gm display
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NAME
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display - display an image on any workstation running X
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Contents
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Synopsis
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gm display [ options ...] file
[options...]file
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Description
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Examples
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To scale an image of a cockatoo to exactly 640 pixels in width and 480
pixels in height and position the window at location (200,200), use:
gm display -geometry 640x480+200+200! cockatoo.miff
To display an image of a cockatoo without a border centered on a backdrop,
use:
gm display +borderwidth -backdrop cockatoo.miff
To tile a slate texture onto the root window, use:
gm display -size 1280x1024 -window root slate.png
To display a visual image directory of all your JPEG images, use:
gm display 'vid:*.jpg'
To display a MAP image that is 640 pixels in width and 480 pixels in height
with 256 colors, use:
gm display -size 640x480+256 cockatoo.map
To display an image of a cockatoo specified with a World Wide Web (WWW)
uniform resource locator (URL), use:
gm display ftp://wizards.dupont.com/images/cockatoo.jpg
To display histogram of an image, use:
gm gm convert file.jpg HISTOGRAM:- | gm display -
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Options
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Options are processed in command line order. Any option you specify on
the command line remains in effect until it is explicitly changed by specifying
the option again with a different effect. For example to display three images,
the first with 32 colors, the second with an unlimited number of colors,
and the third with only 16 colors, use:
gm display -colors 32 cockatoo.miff -noop duck.miff -colors 16 macaw.miff
Display options can appear on the command line or in your X resources
file. See X(1). Options on the command line supersede values specified
in your X resources file.
For a more detailed description of each option, see
Options, above.
GraphicsMagick(1).
| decrypt image with this password |
| display the image centered on a backdrop. |
| surround the image with a border of color |
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-borderwidth <geometry>
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| preferred number of colors in the image |
| annotate an image with a comment |
| the type of image compression |
| enhance or reduce the image contrast |
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-crop <width>x<height>{+-}<x>{+-}<y>{%}
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| preferred size and location of the cropped image |
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-debug <events>
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| add coder/decoder specific options |
| display the next image after pausing |
| horizontal and vertical resolution in pixels of the image |
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-despeckle
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| reduce the speckles within an image |
| specifies the X server to contact |
| apply Floyd/Steinberg error diffusion to the image |
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-edge <radius>
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| detect edges within an image |
| specify endianness (MSB, LSB, or Native) of image |
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-enhance
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| apply a digital filter to enhance a noisy image |
| use this type of filter when resizing an image |
| use this font when annotating the image with text |
| define the foreground color |
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-frame <width>x<height>+<outer bevel width>+<inner bevel width>
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| surround the image with an ornamental border |
| level of gamma correction |
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-geometry <width>x<height>{+-}<x>{+-}<y>{%}{@}{!}{^}{<}{>}
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| Specify dimension, offset, and resize options. |
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-help
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| specify the icon geometry |
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-iconic
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-immutable
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| the type of interlacing scheme |
| assign a label to an image |
| Disk, File, Map, Memory, Pixels, Width, Height, Read, or Threads resource limit |
| Specify format for debug log |
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-magnify <factor>
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| display image using this type. |
| store matte channel if the image has one |
| specify the color to be used with the -frame option |
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-monitor
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-monochrome
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| transform the image to black and white |
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-name
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| replace every pixel with its complementary color |
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-page <width>x<height>{+-}<x>{+-}<y>{%}{!}{<}{>}
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| size and location of an image canvas |
| disable progress monitor and busy cursor |
| JPEG/MIFF/PNG/TIFF compression level |
| lighten or darken image edges |
| perform a X11 remote operation |
| roll an image vertically or horizontally |
| scale image using pixel sampling |
| chroma subsampling factors |
| range of image scene numbers to read |
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-set <attribute> <value>
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-segment <cluster threshold>x<smoothing threshold>
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-size <width>x<height>{+offset}
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| width and height of the image |
| font for writing fixed-width text |
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-texture <filename>
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| name of texture to tile onto the image background |
| assign title to displayed image [animate, display, montage] |
| tree depth for the color reduction algorithm |
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detect when image file is modified and redisplay. |
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-use-pixmap
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| print detailed information about the image |
| print GraphicsMagick version string |
| animate images using this X visual type |
| make image the background of a window |
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-window-group
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| write the image to a file [display] |
For a more detailed description of each option, see
Options, above.
GraphicsMagick(1).
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Mouse Buttons
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The effects of each button press is described below. Three buttons are
required. If you have a two button mouse, button 1 and 3 are returned.
Press ALT and button 3 to simulate button 2.
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1
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Press this button to map or unmap the Command
widget . See the next section for more information about the Command
widget. |
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2
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Press and drag to define a region of the image to magnify. |
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3
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Press and drag to choose from a select set of display(1)
commands. This button behaves differently if the image being displayed
is a visual image directory. Choose a particular tile of the directory
and press this button and drag to select a command from a pop-up menu.
Choose from these menu items: |
- Open
- Next
- Former
- Delete
- Update
If you choose Open, the image represented by the tile is displayed.
To return to the visual image directory, choose Next from the Command
widget (refer to Command Widget).
Next and Former
moves to the next or former image respectively. Choose Delete to
delete a particular image tile. Finally, choose Update to synchronize
all the image tiles with their respective images. See
montage
and
miff for more details.
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Command Widget
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The Command widget lists a number of sub-menus and commands. They are
- File
- Open...
- Next
- Former
- Select...
- Save...
- Print...
- Delete...
- Canvas...
- Visual Directory...
- Quit
- View
- Half Size
- Original Size
- Double Size
- Resize...
- Apply
- Refresh
- Restore
- Transform
- Crop
- Chop
- Flop
- Flip
- Rotate Right
- Rotate Left
- Rotate...
- Shear...
- Roll...
- Trim Edges
- Enhance
- Hue...
- Saturation...
- Brightness...
- Gamma...
- Spiff...
- Dull
- Equalize
- Normalize
- Negate
- GRAYscale
- Quantize...
- Effects
- Despeckle
- Emboss
- Reduce Noise
- Add Noise
- Sharpen...
- Blur...
- Threshold...
- Edge Detect...
- Spread...
- Shade...
- Raise...
- Segment...
- F/X
- Solarize...
- Swirl...
- Implode...
- Wave...
- Oil Paint...
- Charcoal Draw...
- Image Edit
- Annotate...
- Draw...
- Color...
- Matte...
- Composite...
- Add Border...
- Add Frame...
- Comment...
- Launch...
- Region of Interest...
- Miscellany
- Image Info
- Zoom Image
- Show Preview...
- Show Histogram
- Show Matte
- Background...
- Slide Show
- Preferences...
- Help
- Overview
- Browse Documentation
- About Display
Menu items with a indented triangle have a sub-menu. They are represented
above as the indented items. To access a sub-menu item, move the pointer
to the appropriate menu and press button 1 and drag. When you find the
desired sub-menu item, release the button and the command is executed.
Move the pointer away from the sub-menu if you decide not to execute a
particular command.
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Keyboard Accelerators
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Accelerators are one or two key presses that effect a particular command.
The keyboard accelerators that
display understands is:
Ctl+O Press to load an image from a file.
space Press to display the next image.
If the image is a multi-paged document such as a
PostScript document,
you can skip ahead several pages by preceding this command with a number.
For example to display the fourth page beyond the current page,
press 4space.
backspace Press to display the former image.
If the image is a multi-paged document such as a
PostScript document,
you can skip behind several pages by preceding this command with a number.
For example to display the fourth page preceding the current page, press
4n.
Ctl-S Press to save the image to a file.
Ctl-P Press to print the image to a
PostScript printer.
Ctl-D Press to delete an image file.
Ctl-N Press to create a blank canvas.
Ctl-Q Press to discard all images and exit program.
Ctl+Z Press to undo last image transformation.
Ctl+R Press to redo last image transformation.
Ctl-X Press to cut a region of
the image.
Ctl-C Press to copy a region of
the image.
Ctl-V Press to paste a region to
the image.
< Press to halve the image size.
. Press to return to the original image size.
> Press to double the image size.
% Press to resize the image to a width and height
you specify.
Cmd-A Press to make any image transformations
permanent.
By default, any image size transformations are
applied to the original image to create the
image displayed on the X server. However, the
transformations are not permanent (i.e. the
original image does not change size only the
X image does). For example, if you press ">"
the X image will appear to double in size, but
the original image will in fact remain the same
size. To force the original image to double in
size, press ">" followed by "Cmd-A".
@ Press to refresh the image window.
C Press to crop the image.
[ Press to chop the image.
H Press to flop image in the horizontal direction.
V Press to flip image in the vertical direction.
/ Press to rotate the image 90 degrees clockwise.
\ Press to rotate the image 90 degrees
counter-clockwise.
* Press to rotate the image
the number of degrees you specify.
S Press to shear the image the number of degrees
you specify.
R Press to roll the image.
T Press to trim the image edges.
Shft-H Press to vary the color hue.
Shft-S Press to vary the color saturation.
Shft-L Press to vary the image brightness.
Shft-G Press to gamma correct the image.
Shft-C Press to spiff up the image contrast.
Shft-Z Press to dull the image contrast.
= Press to perform histogram equalization on
the image.
Shft-N Press to perform histogram normalization on
the image.
Shft-~ Press to negate the colors of the image.
. Press to convert the image colors to gray.
Shft-# Press to set the maximum number of unique
colors in the image.
F2 Press to reduce the speckles in an image.
F2 Press to emboss an image.
F4 Press to eliminate peak noise from an image.
F5 Press to add noise to an image.
F6 Press to sharpen an image.
F7 Press to blur image an image.
F8 Press to threshold the image.
F9 Press to detect edges within an image.
F10 Press to displace pixels by a random amount.
F11 Press to shade the image using a distant light
source.
F12 Press to lighten or darken image edges to
create a 3-D effect.
F13 Press to segment the image by color.
Meta-S Press to swirl image pixels about the center.
Meta-I Press to implode image pixels about the center.
Meta-W Press to alter an image along a sine wave.
Meta-P Press to simulate an oil painting.
Meta-C Press to simulate a charcoal drawing.
Alt-X Press to composite the image
with another.
Alt-A Press to annotate the image with text.
Alt-D Press to draw a line on the image.
Alt-P Press to edit an image pixel color.
Alt-M Press to edit the image matte information.
Alt-X Press to composite the image with another.
Alt-A Press to add a border to the image.
Alt-F Press to add a ornamental frame to the image.
Alt-Shft-! Press to add an image comment.
Ctl-A Press to apply image processing techniques to a
region of interest.
Shft-? Press to display information about the image.
Shft-+ Press to map the zoom image window.
Shft-P Press to preview an image enhancement, effect,
or f/x.
F1 Press to display helpful information about
the "display" utility.
Find Press to browse documentation about
GraphicsMagick.
1-9 Press to change the level of magnification.
Use the arrow keys to move the image one pixel up, down, left, or right
within the magnify window. Be sure to first map the magnify window by pressing
button 2.
Press ALT and one of the arrow keys to trim off one pixel from any side
of the image.
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X Resources
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Display options can appear on the command line or in your X resource
file. Options on the command line supersede values specified in your X
resource file. See X(1) for more information on X resources.
Most display options have a corresponding X resource. In addition,
display
uses the following X resources:
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background (class Background)
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Specifies the preferred color to use for the Image window background. The
default is #ccc. |
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borderColor (class BorderColor)
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Specifies the preferred color to use for the Image window border. The default
is #ccc. |
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borderWidth (class BorderWidth)
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Specifies the width in pixels of the image window border. The default is
2. |
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browseCommand (class browseCommand)
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Specifies the name of the preferred browser when displaying GraphicsMagick
documentation. The default is netscape %s. |
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confirmExit (class ConfirmExit)
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Display pops up a dialog box to confirm exiting the program when
exiting the program. Set this resource to False to exit without
a confirmation. |
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displayGamma (class DisplayGamma)
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Specifies the gamma of the X server. |
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You can apply separate gamma values to the red, green, and blue channels
of the image with a gamma value list delineated with slashes (i.e. 1.7/2.3/1.2). |
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displayWarnings (class DisplayWarnings)
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Display pops up a dialog box whenever a warning message occurs.
Set this resource to False to ignore warning messages. |
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font (class FontList)
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Specifies the name of the preferred font to use in normal formatted text.
The default is 14 point Helvetica. |
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font[1-9] (class Font[1-9])
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Specifies the name of the preferred font to use when
annotating
the image window with text. The default fonts are fixed, variable, 5x8,
6x10, 7x13bold, 8x13bold, 9x15bold, 10x20, and 12x24. |
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foreground (class Foreground)
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Specifies the preferred color to use for text within the image window.
The default is black. |
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gammaCorrect (class gammaCorrect)
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This resource, if true, will lighten or darken an image of known gamma
to match the gamma of the display (see resource displayGamma). The
default is True. |
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geometry (class Geometry)
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Specifies the preferred size and position of the image window. It is not
necessarily obeyed by all window managers. |
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Offsets, if present, are handled in X(1) style. A negative x offset is
measured from the right edge of the screen to the right edge of the icon,
and a negative y offset is measured from the bottom edge of the screen
to the bottom edge of the icon. |
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iconGeometry (class IconGeometry)
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Specifies the preferred size and position of the application when iconified.
It is not necessarily obeyed by all window managers. |
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Offsets, if present, are handled in the same manner as in class Geometry. |
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iconic (class Iconic)
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This resource indicates that you would prefer that the application's windows
initially not be visible as if the windows had be immediately iconified
by you. Window managers may choose not to honor the application's request. |
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magnify (class Magnify)
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specifies an integral factor by which the image should be enlarged. The
default is 3. |
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This value only affects the magnification window which is invoked with
button
number 3 after the image is displayed. |
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matteColor (class MatteColor)
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Specify the color of windows. It is used for the backgrounds of windows,
menus, and notices. A 3D effect is achieved by using highlight and shadow
colors derived from this color. Default value: #697B8F. |
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name (class Name)
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This resource specifies the name under which resources for the application
should be found. This resource is useful in shell aliases to distinguish
between invocations of an application, without resorting to creating links
to alter the executable file name. The default is the application name. |
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pen[1-9] (class Pen[1-9])
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Specifies the color of the preferred font to use when
annotating
the image window with text. The default colors are black, blue, green,
cyan, gray, red, magenta, yellow, and white. |
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printCommand (class PrintCommand)
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This command is executed whenever Print is issued. In general, it is the
command to print PostScript to your printer. Default value: lp
-c -s %i. |
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sharedMemory (class SharedMemory)
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This resource specifies whether display should attempt use shared memory
for pixmaps. GraphicsMagick must be compiled with shared memory support,
and the display must support the MIT-SHM extension. Otherwise, this
resource is ignored. The default is True. |
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textFont (class textFont)
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Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text. The default is 14 point Courier. |
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title (class Title)
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This resource specifies the title to be used for the image window. This
information is sometimes used by a window manager to provide a header identifying
the window. The default is the image file name. |
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undoCache (class UndoCache)
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Specifies, in mega-bytes, the amount of memory in the undo edit cache.
Each time you modify the image it is saved in the undo edit cache as long
as memory is available. You can subsequently undo one or more of
these transformations. The default is 16 Megabytes. |
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usePixmap (class UsePixmap)
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Images are maintained as a XImage by default. Set this resource to True
to utilize a server Pixmap instead. This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image. Panning is much faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with discretion. |
To set the geometry of the Magnify or Pan or window, use the geometry resource.
For example, to set the Pan window geometry to 256x256, use:
gm display.pan.geometry: 256x256
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Image Loading
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To select an image to display, choose Open of the File sub-menu
from the Command widget. A file browser is displayed.
To choose a particular image file, move the pointer to the filename and
press any button. The filename is copied to the text window. Next, press
Open
or press the RETURN key. Alternatively, you can type the image file
name directly into the text window. To descend directories, choose a directory
name and press the button twice quickly. A scrollbar allows a large list
of filenames to be moved through the viewing area if it exceeds the size
of the list area.
You can trim the list of file names by using shell globbing characters.
For example, type *.jpg to list only files that end
with .jpg.
To select your image from the X server screen instead of from a file, Choose
Grab of the Open widget.
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Visual Image Directory
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To create a Visual Image Directory, choose Visual Directory of the File
sub-menu from the Command widget . A file browser is
displayed. To create a Visual Image Directory from all the images in the
current directory, press Directory or press the RETURN key.
Alternatively, you can select a set of image names by using shell globbing
characters. For example, type *.jpg to include only files that
end with .jpg. To descend directories, choose a directory name
and press the button twice quickly. A scrollbar allows a large list of
filenames to be moved through the viewing area if it exceeds the size of
the list area.
After you select a set of files, they are turned into thumbnails and tiled
onto a single image. Now move the pointer to a particular thumbnail and
press button 3 and drag. Finally, select Open. The image represented
by the thumbnail is displayed at its full size. Choose Next from
the File sub-menu of the Command widget to return to the Visual
Image Directory.
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Image Cutting
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Note that cut information for image window is not retained for colormapped
X server visuals (e.g. StaticColor,
StaticColor, GRAYScale,
PseudoColor).
Correct cutting behavior may require a TrueColor or DirectColor
visual or a Standard Colormap.
To begin, press choose Cut of the Edit sub-menu from the
Command
widget. Alternatively, press
F3 in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in cut mode. In cut mode, the Command widget has these
options:
To define a cut region, press button 1 and drag. The cut region is defined
by a highlighted rectangle that expands or contracts as it follows the
pointer. Once you are satisfied with the cut region, release the button.
You are now in rectify mode. In rectify mode, the Command widget has these
options:
You can make adjustments by moving the pointer to one of the cut rectangle
corners, pressing a button, and dragging. Finally, press Cut to commit
your copy region. To exit without cutting the image, press Dismiss.
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Image Copying
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To begin, press choose Copy of the Edit sub-menu from the
Command
widget. Alternatively, press
F4 in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in copy mode. In copy mode, the Command widget has
these options:
To define a copy region, press button 1 and drag. The copy region is defined
by a highlighted rectangle that expands or contracts as it follows the
pointer. Once you are satisfied with the copy region, release the button.
You are now in rectify mode. In rectify mode, the Command widget has these
options:
You can make adjustments by moving the pointer to one of the copy rectangle
corners, pressing a button, and dragging. Finally, press Copy to commit
your copy region. To exit without copying the image, press Dismiss.
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Image Pasting
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To begin, press choose Paste of the Edit sub-menu from the
Command
widget. Alternatively, press
F5 in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in Paste mode. To exit immediately, press Dismiss.
In Paste mode, the Command widget has these options:
- Operators
- over
- in
- out
- atop
- xor
- plus
- minus
- add
- subtract
- difference
- multiply
- bumpmap
- replace
- Help
- Dismiss
Choose a composite operation from the Operators sub-menu of the
Command
widget. How each operator behaves is described below. image window
is the image currently displayed on your X server and image is the
image obtained with the File Browser widget.
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over
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The result is the union of the two image shapes, with image obscuring
image
window in the region of overlap. |
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in
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The result is simply image cut by the shape of
image window.
None of the image data of image window is in the result. |
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out
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The resulting image is image with the shape of
image window
cut out. |
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atop
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The result is the same shape as image window, with
image
obscuring image window where the image shapes overlap. Note this
differs from over because the portion of image outside
image window's
shape does not appear in the result. |
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xor
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The result is the image data from both image and
image window
that is outside the overlap region. The overlap region is blank. |
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plus
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The result is just the sum of the image data. Output values are cropped
to the maximum value (no overflow). This operation is independent of the
matte channels. |
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minus
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The result of image - image window, with underflow cropped
to zero. The matte channel is ignored (set to opaque, full coverage). |
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add
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The result of image + image window, with overflow wrapping
around (mod MaxRGB+1). |
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subtract
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The result of image - image window, with underflow wrapping
around (mod MaxRGB+1). The add and subtract operators can be used to perform
reversible transformations. |
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difference
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The result of abs(image - image window). This is useful for
comparing two very similar images. |
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multiply
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The result of image * image window. This is useful for
the creation of drop-shadows. |
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bumpmap
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The result of image window shaded by window. |
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replace
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image.
Here the matte information is ignored. |
The image compositor requires a matte, or alpha channel in the image for
some operations. This extra channel usually defines a mask which represents
a sort of a cookie-cutter for the image. This is the case when matte is
255 (full coverage) for pixels inside the shape, zero outside, and between
zero and 255 on the boundary. If image does not have a matte channel, it
is initialized with 0 for any pixel matching in color to pixel location
(0,0), otherwise 255. See Matte Editing for a method
of defining a matte channel.
Note that matte information for image window is not retained for colormapped
X server visuals (e.g. StaticColor, StaticColor, GrayScale, PseudoColor).
Correct compositing behavior may require a
TrueColor or DirectColor
visual or a Standard Colormap.
Choosing a composite operator is optional. The default operator is replace.
However, you must choose a location to composite your image and press button
1. Press and hold the button before releasing and an outline of the image
will appear to help you identify your location.
The actual colors of the pasted image is saved. However, the color that
appears in image window may be different. For example, on a monochrome
screen image window will appear black or white even though your pasted
image may have many colors. If the image is saved to a file it is written
with the correct colors. To assure the correct colors are saved in the
final image, any PseudoClass image is promoted to DirectClass.
To force a
PseudoClass image to remain PseudoClass,
use -colors.
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Image Cropping
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To begin, press choose Crop of the Transform submenu from
the Command widget. Alternatively,
press C in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in crop mode. In crop mode, the Command widget has
these options:
To define a cropping region, press button 1 and drag. The cropping region
is defined by a highlighted rectangle that expands or contracts as it follows
the pointer. Once you are satisfied with the cropping region, release the
button. You are now in rectify mode. In rectify mode, the Command widget
has these options:
You can make adjustments by moving the pointer to one of the cropping rectangle
corners, pressing a button, and dragging. Finally, press Crop to commit
your cropping region. To exit without cropping the image, press Dismiss.
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Image Chopping
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An image is chopped interactively. There is no command line argument to
chop an image. To begin, choose Chop of the Transform sub-menu
from the Command widget. Alternatively,
press [ in the Image window.
You are now in Chop mode. To exit immediately, press
Dismiss.
In Chop mode, the Command widget has these options:
If the you choose the horizontal direction (this is the default), the area
of the image between the two horizontal endpoints of the chop line is removed.
Otherwise, the area of the image between the two vertical endpoints of
the chop line is removed.
Select a location within the image window to begin your chop, press and
hold any button. Next, move the pointer to another location in the image.
As you move a line will connect the initial location and the pointer. When
you release the button, the area within the image to chop is determined
by which direction you choose from the Command widget.
To cancel the image chopping, move the pointer back to the starting point
of the line and release the button.
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Image Rotation
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Press the / key to rotate the image 90 degrees or \ to rotate -90 degrees.
To interactively choose the degree of rotation, choose
Rotate...
of the Transform submenu from the Command Widget.
Alternatively, press * in the image window.
A small horizontal line is drawn next to the pointer. You are now in rotate
mode. To exit immediately, press Dismiss. In rotate mode, the Command widget
has these options:
- Pixel Color
- black
- blue
- cyan
- green
- gray
- red
- magenta
- yellow
- white
- Browser...
- Direction
- Help
- Dismiss
Choose a background color from the Pixel Color sub-menu. Additional background
colors can be specified with the color browser. You can change the menu
colors by setting the X resources pen1 through pen9.
If you choose the color browser and press Grab, you can select the
background color by moving the pointer to the desired color on the screen
and press any button.
Choose a point in the image window and press this button and hold. Next,
move the pointer to another location in the image. As you move a line connects
the initial location and the pointer. When you release the button, the
degree of image rotation is determined by the slope of the line you just
drew. The slope is relative to the direction you choose from the Direction
sub-menu of the Command widget.
To cancel the image rotation, move the pointer back to the starting point
of the line and release the button.
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Image Segmentation
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Choose Effects->Segment to segment an image by analyzing the histograms
of the color components and identifying units that are homogeneous with
the fuzzy c-means technique. The scale-space filter analyzes the histograms
of the three color components of the image and identifies a set of classes.
The extents of each class is used to coarsely segment the image with thresholding.
The color associated with each class is determined by the mean color of
all pixels within the extents of a particular class. Finally, any unclassified
pixels are assigned to the closest class with the fuzzy c-means technique.
The fuzzy c-Means algorithm can be summarized as follows:
-
Build a histogram, one for each color component of the image.
-
For each histogram, successively apply the scale-space filter and build
an interval tree of zero crossings in the second derivative at each scale.
Analyze this scale-space "fingerprint" to determine which peaks or valleys
in the histogram are most predominant.
-
The fingerprint defines intervals on the axis of the histogram. Each interval
contains either a minima or a maxima in the original signal. If each color
component lies within the maxima interval, that pixel is considered "classified"
and is assigned an unique class number.
-
Any pixel that fails to be classified in the above thresholding pass is
classified using the fuzzy c-Means technique. It is assigned to one of
the classes discovered in the histogram analysis phase.
The fuzzy c-Means technique attempts to cluster a pixel by finding the
local minima of the generalized within group sum of squared error objective
function. A pixel is assigned to the closest class of which the fuzzy membership
has a maximum value.
For additional information see:
Young Won Lim, Sang Uk Lee, "On The Color Image Segmentation
Algorithm Based on the Thresholding and the Fuzzy c-Means Techniques",
Pattern Recognition, Volume 23, Number 9, pages 935-952, 1990.
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Image Annotation
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An image is annotated interactively. There is no command line argument
to annotate an image. To begin, choose
Annotate of the Image
Edit sub-menu from the Command widget. Alternatively,
press a in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in annotate mode. To exit immediately, press Dismiss.
In annotate mode, the Command widget has these options:
-
Font Name
-
fixed
-
variable
-
5x8
-
6x10
-
7x13bold
-
8x13bold
-
9x15bold
-
10x20
-
12x24
-
Browser...
-
Font Color
-
black
-
blue
-
cyan
-
green
-
gray
-
red
-
magenta
-
yellow
-
white
-
transparent
-
Browser...
-
Box Color
-
black
-
blue
-
cyan
-
green
-
gray
-
red
-
magenta
-
yellow
-
white
-
transparent
-
Browser...
-
Rotate Text
-
-90
-
-45
-
-30
-
0
-
30
-
45
-
90
-
180
-
Dialog...
-
Help
-
Dismiss
Choose a font name from the Font Name sub-menu. Additional font
names can be specified with the font browser. You can change the menu names
by setting the X resources font1 through font9.
Choose a font color from the Font Color sub-menu. Additional font
colors can be specified with the color browser. You can change the menu
colors by setting the X resources pen1 through pen9.
If you select the color browser and press Grab, you can choose the
font color by moving the pointer to the desired color on the screen and
press any button.
If you choose to rotate the text, choose Rotate Text from the menu
and select an angle. Typically you will only want to rotate one line of
text at a time. Depending on the angle you choose, subsequent lines may
end up overwriting each other.
Choosing a font and its color is optional. The default font is fixed and
the default color is black. However, you must choose a location to begin
entering text and press a button. An underscore character will appear at
the location of the pointer. The cursor changes to a pencil to indicate
you are in text mode. To exit immediately, press Dismiss.
In text mode, any key presses will display the character at the location
of the underscore and advance the underscore cursor. Enter your text and
once completed press Apply to finish your image annotation. To correct
errors press BACK SPACE. To delete an entire line of text, press
DELETE.
Any text that exceeds the boundaries of the image window is automatically
continued onto the next line.
The actual color you request for the font is saved in the image. However,
the color that appears in your Image window may be different. For example,
on a monochrome screen the text will appear black or white even if you
choose the color red as the font color. However, the image saved to a file
with -write is written with red lettering. To assure the correct
color text in the final image, any PseudoClass image is promoted
to DirectClass (see miff(5)). To force a PseudoClass image
to remain
PseudoClass, use -colors.
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Image Compositing
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An image composite is created interactively. There is no command line
argument to composite an image. To begin, choose Composite of
the Image Edit from the Command widget. Alternatively,
press x in the Image window.
First a popup window is displayed requesting you to enter an image name.
Press Composite, Grab or type a file name. Press Cancel
if you choose not to create a composite image. When you choose Grab,
move the pointer to the desired window and press any button.
If the Composite image does not have any matte information, you
are informed and the file browser is displayed again. Enter the name of
a mask image. The image is typically grayscale and the same size as the
composite image. If the image is not grayscale, it is converted to grayscale
and the resulting intensities are used as matte information.
A small window appears showing the location of the cursor in the image
window. You are now in composite mode. To exit immediately, press Dismiss.
In composite mode, the Command widget has these options:
-
Operators
-
over
-
in
-
out
-
atop
-
xor
-
plus
-
minus
-
add
-
subtract
-
difference
-
bumpmap
-
replace
-
Blend
-
Displace
-
Help
-
Dismiss
Choose a composite operation from the Operators sub-menu of the Command
widget. How each operator behaves is described below. image window is the
image currently displayed on your X server and image is the image obtained
|
over
|
|
The result is the union of the two image shapes, with image obscuring
image
window in the region of overlap. |
|
in
|
|
The result is simply image cut by the shape of
image window.
None of the image data of image window is in the result. |
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out
|
|
The resulting image is image with the shape of
image window
cut out. |
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atop
|
|
The result is the same shape as image window, with
image
obscuring image window where the image shapes overlap. Note this
differs from over because the portion of image outside
image window's
shape does not appear in the result. |
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xor
|
|
The result is the image data from both image and
image window
that is outside the overlap region. The overlap region is blank. |
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plus
|
|
The result is just the sum of the image data. Output values are cropped
to 255 (no overflow). This operation is independent of the matte channels. |
|
minus
|
|
The result of image - image window, with underflow cropped
to zero. The matte channel is ignored (set to 255, full coverage). |
|
add
|
|
The result of image + image window, with overflow wrapping
around (mod 256). |
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subtract
|
|
The result of image - image window, with underflow wrapping
around (mod 256). The add and subtract operators can be used to perform
reversible transformations. |
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difference
|
|
The result of abs(image - image window). This is useful for
comparing two very similar images. |
|
bumpmap
|
|
The result of image window shaded by window. |
|
replace
|
|
The resulting image is image window replaced with
image.
Here the matte information is ignored. |
The image compositor requires a matte, or alpha channel in the image for
some operations. This extra channel usually defines a mask which represents
a sort of a cookie-cutter for the image. This is the case when matte is
255 (full coverage) for pixels inside the shape, zero outside, and between
zero and 255 on the boundary. If image does not have a matte channel, it
is initialized with 0 for any pixel matching in color to pixel location
(0,0), otherwise 255. See Matte Editing for a method
of defining a matte channel.
If you choose blend, the composite operator becomes over.
The image matte channel percent transparency is initialized to factor.
The image window is initialized to (100-factor). Where factor is the value
you specify in the Dialog widget.
Displace shifts the image pixels as defined by a displacement map.
With this option, image is used as a displacement map. Black, within
the displacement map, is a maximum positive displacement. White is a maximum
negative displacement and middle gray is neutral. The displacement is scaled
to determine the pixel shift. By default, the displacement applies in both
the horizontal and vertical directions. However, if you specify
mask,
image
is the horizontal X displacement and
mask the vertical Y displacement.
Note that matte information for image window is not retained for colormapped
X server visuals (e.g.
StaticColor, StaticColor, GrayScale, PseudoColor).
Correct compositing behavior may require a TrueColor or
DirectColor
visual or a Standard Colormap.
Choosing a composite operator is optional. The default operator is replace.
However, you must choose a location to composite your image and press button
1. Press and hold the button before releasing and an outline of the image
will appear to help you identify your location.
The actual colors of the composite image is saved. However, the color that
appears in image window may be different. For example, on a monochrome
screen Image window will appear black or white even though your composited
image may have many colors. If the image is saved to a file it is written
with the correct colors. To assure the correct colors are saved in the
final image, any PseudoClass image is promoted to DirectClass (see
miff).
To force a PseudoClass image to remain PseudoClass,
use -colors.
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Color Editing
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Changing the the color of a set of pixels is performed interactively. There
is no command line argument to edit a pixel. To begin, choose Color
from the Image Edit submenu of the Command widget.
Alternatively, press c in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in color edit mode. To exit immediately, press Dismiss.
In color edit mode, the
Command widget has these options:
-
Method
-
point
-
replace
-
floodfill
-
reset
-
Pixel Color
-
black
-
blue
-
cyan
-
green
-
gray
-
red
-
magenta
-
yellow
-
white
-
Browser...
-
Border Color
-
black
-
blue
-
cyan
-
green
-
gray
-
red
-
magenta
-
yellow
-
white
-
Browser...
-
Fuzz
-
Undo
-
Help
-
Dismiss
Choose a color editing method from the Method sub-menu of
the Command
widget. The point method recolors any pixel selected with the
pointer unless the button is released. The replace method recolors
any pixel that matches the color of the pixel you select with a button
press. Floodfill recolors any pixel that matches the color of the
pixel you select with a button press and is a neighbor.
Whereas filltoborder
changes the matte value of any neighbor pixel that is not the border color.
Finally reset changes the entire image to the designated color.
Next, choose a pixel color from the Pixel Color sub-menu. Additional
pixel colors can be specified with the color browser. You can change the
menu colors by setting the X resources pen1 through
pen9.
Now press button 1 to select a pixel within the Image window to change
its color. Additional pixels may be recolored as prescribed by the method
you choose. additional pixels by increasing the Delta value.
If the Magnify widget is mapped, it can be helpful in positioning
your pointer within the image (refer to button 2). Alternatively you can
select a pixel to recolor from within the Magnify widget. Move the
pointer to the Magnify widget and position the pixel with the cursor
control keys. Finally, press a button to recolor the selected pixel (or
pixels).
The actual color you request for the pixels is saved in the image. However,
the color that appears in your Image window may be different. For example,
on a monochrome screen the pixel will appear black or white even if you
choose the color red as the pixel color. However, the image saved to a
file with -write is written with red pixels. To assure the correct color
text in the final image, any PseudoClass image is promoted
to DirectClass
To force a PseudoClass image to remain
PseudoClass, use -colors.
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Matte Editing
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Matte information within an image is useful for some operations such as
image compositing. This extra channel usually defines
a mask which represents a sort of a cookie-cutter for the image. This is
the case when matte is 255 (full coverage) for pixels inside the shape,
zero outside, and between zero and 255 on the boundary.
Setting the matte information in an image is done interactively. There
is no command line argument to edit a pixel. To begin, and choose Matte
of the Image Edit sub-menu from the Command widget.
Alternatively, press m in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in matte edit mode. To exit immediately, press Dismiss.
In matte edit mode, the Command widget has these options:
-
Method
-
point
-
replace
-
floodfill
-
reset
-
Border Color
-
black
-
blue
-
cyan
-
green
-
gray
-
red
-
magenta
-
yellow
-
white
-
Browser...
-
Fuzz
-
Matte
-
Undo
-
Help
-
Dismiss
Choose a matte editing method from the Method sub-menu of the Command
widget. The point method changes the matte value of the any
pixel selected with the pointer until the button is released. The replace
method changes the matte value of any pixel that matches the color
of the pixel you select with a button press. Floodfill changes the
matte value of any pixel that matches the color of the pixel you select
with a button press and is a neighbor. Whereas
filltoborder recolors
any neighbor pixel that is not the border color. Finally reset changes
the entire image to the designated matte value.
Choose Matte Value and a dialog appears requesting a matte value.
Enter a value between 0 and 255. This value is assigned as the matte
value of the selected pixel or pixels.
Now, press any button to select a pixel within the Image window to change
its matte value. You can change the matte value of additional pixels by
increasing the Delta value. The Delta value is first added then subtracted
from the red, green, and blue of the target color. Any pixels within the
range also have their matte value updated.
If the Magnify widget is mapped, it can be helpful in positioning
your pointer within the image (refer to button 2). Alternatively you can
select a pixel to change the matte value from within the
Magnify widget.
Move the pointer to the Magnify widget and position the pixel with
the cursor control keys. Finally, press a button to change the matte value
of the selected pixel (or pixels).
Matte information is only valid in a DirectClass image. Therefore,
any PseudoClass image is promoted to
DirectClass. Note that
matte information for PseudoClass is not retained for colormapped
X server visuals (e.g. StaticColor, StaticColor, GrayScale, PseudoColor)
unless you immediately save your image to a file (refer to Write). Correct
matte editing behavior may require a TrueColor or DirectColor
visual or a Standard Colormap.
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Image Drawing
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An image is drawn upon interactively. There is no command line argument
to draw on an image. To begin, choose Draw of the Image Edit
sub-menu from the Command widget.
Alternatively, press d in the image window.
The cursor changes to a crosshair to indicate you are in draw mode. To
exit immediately, press Dismiss. In draw mode, the Command widget has these
options:
-
Primitive
-
point
-
line
-
rectangle
-
fill rectangle
-
circle
-
fill circle
-
ellipse
-
fill ellipse
-
polygon
-
fill polygon
-
Color
-
black
-
blue
-
cyan
-
green
-
gray
-
red
-
magenta
-
yellow
-
white
-
transparent
-
Browser...
-
Stipple
-
Brick
-
Diagonal
-
Scales
-
Vertical
-
Wavy
-
Translucent
-
Opaque
-
Open...
-
Width
-
Undo
-
Help
-
Dismiss
Choose a drawing primitive from the Primitive sub-menu.
Next, choose a color from the Color sub-menu. Additional colors
can be specified with the color browser. You can change the menu colors
by setting the X resources pen1 through pen9. The transparent
color updates the image matte channel and is useful for image compositing.
If you choose the color browser and press Grab, you can select the
primitive color by moving the pointer to the desired color on the screen
and press any button. The transparent color updates the image matte channel
and is useful for image compositing.
Choose a stipple, if appropriate, from the Stipple sub-menu. Additional
stipples can be specified with the file browser. Stipples obtained from
the file browser must be on disk in the X11 bitmap format.
Choose a line width, if appropriate, from the Width sub-menu. To
choose a specific width select the Dialog widget.
Choose a point in the image window and press button 1 and hold. Next, move
the pointer to another location in the image. As you move, a line connects
the initial location and the pointer. When you release the button, the
image is updated with the primitive you just drew. For polygons, the image
is updated when you press and release the button without moving the pointer.
To cancel image drawing, move the pointer back to the starting point of
the line and release the button.
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Region of Interest
|
|
To begin, press choose Region of Interest of the Pixel Transform sub-menu
from the Command widget.
Alternatively, press R in the image window.
A small window appears showing the location of the cursor in the image
window. You are now in region of interest mode. In region of interest mode,
the Command widget has these options:
To define a region of interest, press button 1 and drag. The region of
interest is defined by a highlighted rectangle that expands or contracts
as it follows the pointer. Once you are satisfied with the region of interest,
release the button. You are now in apply mode. In apply mode the Command
widget has these options:
-
File
-
Edit
-
Transform
-
Flip
-
Flop
-
Rotate Right
-
Rotate Left
-
Enhance
-
Hue...
-
Saturation...
-
Brightness...
-
Gamma...
-
Spiff
-
Dull
-
Equalize
-
Normalize
-
Negate
-
GRAYscale
-
Quantize...
-
Effects
-
Despeckle
-
Emboss
-
Reduce Noise
-
Add Noise
-
Sharpen...
-
Blur...
-
Threshold...
-
Edge Detect...
-
Spread...
-
Shade...
-
Raise...
-
Segment...
-
F/X
-
Solarize...
-
Swirl...
-
Implode...
-
Wave...
-
Oil Paint
-
Charcoal Draw...
-
Miscellany
-
Image Info
-
Zoom Image
-
Show Preview...
-
Show Histogram
-
Show Matte
-
Help
-
Dismiss
You can make adjustments to the region of interest by moving the pointer
to one of the rectangle corners, pressing a button, and dragging. Finally,
choose an image processing technique from the Command widget. You can choose
more than one image processing technique to apply to an area. Alternatively,
you can move the region of interest before applying another image processing
technique. To exit, press Dismiss.
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Image Panning
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When an image exceeds the width or height of the X server screen, display
maps a small panning icon. The rectangle within the panning icon shows
the area that is currently displayed in the the image window. To pan about
the image, press any button and drag the pointer within the panning icon.
The pan rectangle moves with the pointer and the image window is updated
to reflect the location of the rectangle within the panning icon. When
you have selected the area of the image you wish to view, release the button.
Use the arrow keys to pan the image one pixel up, down, left, or right
within the image window.
The panning icon is withdrawn if the image becomes smaller than the dimensions
of the X server screen.
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User Preferences
|
|
Preferences affect the default behavior of display(1). The preferences
are either true or false and are stored in your home directory
as .displayrc:
-
display image centered on a backdrop
-
This backdrop covers the entire workstation screen and is useful for hiding
other X window activity while viewing the image. The color of the backdrop
is specified as the background color. Refer to X Resources
for details.
-
confirm on program exit
-
Ask for a confirmation before exiting the display(1) program.
-
correct image for display gamma
-
If the image has a known gamma, the gamma is corrected to match that of
the X server (see the X Resource displayGamma).
-
display warning messages
-
Display any warning messages.
-
apply Floyd/Steinberg error diffusion to image
-
The basic strategy of dithering is to trade intensity resolution for spatial
resolution by averaging the intensities of several neighboring pixels.
Images which suffer from severe contouring when reducing colors can be
improved with this preference.
-
use a shared colormap for colormapped X visuals
-
This option only applies when the default X server visual is
PseudoColor
or GRAYScale. Refer to -visual for more details. By default,
a shared colormap is allocated. The image shares colors with other X clients.
Some image colors could be approximated, therefore your image may look
very different than intended. Otherwise the image colors appear exactly
as they are defined. However, other clients may go technicolor when the
image colormap is installed.
-
display images as an X server pixmap
-
Images are maintained as a XImage by default. Set this resource to True
to utilize a server Pixmap instead. This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image. Panning is much faster with Pixmaps than with a XImage. Pixmaps
are considered a precious resource, use them with discretion.
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load an image from a file