|
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 two images,
the first with 32 colors, and the second with only 16 colors, use:
display -colors 32 cockatoo.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.
| display the 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.
|
| surround the image with a border of color |
|
See X(1) for details
about the geometry specification.
|
| megabytes of memory available to the pixel cache |
|
Image pixels are stored in memory until 80 megabytes of memory have been
consumed. Subsequent pixel operations are cached on disk. Operations to
memory are significantly faster but if your computer does not have a sufficient
amount of free memory you may want to adjust this threshold value.
|
|
Choose between shared or private.
|
|
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. Choose Private and the image colors
appear exactly as they are defined. However, other clients may
go technicolor when the image colormap is installed. |
| preferred number of colors in the image |
|
The actual number of colors in the image may be less than your request,
but never more. Note, this is a color reduction option. Images with less
unique colors than specified with this option will have any duplicate or
unused colors removed. Refer to quantize for
more details.
|
|
Note, options -dither, -colorspace, and -treedepth
affect the color reduction algorithm.
|
|
Choices are: GRAY, OHTA, RGB,
Transparent,
XYZ,
YCbCr, YIQ, YPbPr,
YUV, or CMYK.
|
|
Color reduction, by default, takes place in the RGB color space. Empirical
evidence suggests that distances in color spaces such as YUV or YIQ correspond
to perceptual color differences more closely than do distances in RGB space.
These color spaces may give better results when color reducing an image.
Refer to quantize for more details.
|
|
The Transparent color space behaves uniquely in that it preserves
the matte channel of the image if it exists.
|
|
The -colors or -monochrome option is required for this
option to take effect.
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| annotate an image with a comment |
|
Use this option to assign a specific comment to the image. You can include the
image filename, type, width, height, or other image attribute by embedding
special format characters:
|
%b file size
%c comment
%d directory
%e filename extention
%f filename
%h height
%i input filename
%k number of unique colors
%l label
%m magick
%n number of scenes
%o output filename
%p page number
%q quantum depth
%s scene number
%t top of filename
%u unique temporary filename
%w width
%x x resolution
%y y resolution
\n newline
\r carriage return
-comment "%m:%f %wx%h"
|
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.
|
|
If the first character of string is @, the image comment
is read from a file titled by the remaining characters in the string.
|
| the type of image compression |
|
Choices are: None, BZip, Fax,
Group4,
JPEG,
LZW, RLE or Zip.
|
|
Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file.
|
| enhance or reduce the image contrast |
|
This option enhances the intensity differences between the lighter and
darker elements of the image. Use -contrast to enhance
the image
or +contrast to reduce the image contrast.
|
|
-crop <width>x<height>{+-}<x offset>{+-}<y offset>{%}
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| preferred size and location of the cropped image |
|
See X(1) for details
about the geometry specification.
|
|
The width and height give the size of the image that remains after cropping,
and the offsets give the location of the top left corner of the cropped
image with respect to the original image. To specify the amount to be
removed, use -shave instead.
|
|
To specify a percentage width or height to be removed instead, append
%. For example
to crop the image by ten percent (five percent on each side of the image),
use -crop 10%.
|
|
Use cropping to apply image processing options to, or display, a particular
area of an image.
|
|
Omit the x and y offset to generate one or more subimages of a uniform
size.
|
|
Use cropping to crop a particular area of an image. Use -crop 0x0
to trim edges that are the background color. Add an x and y offset to leave
a portion of the trimmed edges with the image.
|
| display the next image after pausing |
|
This option is useful for regulating the animation of GIF images
within Netscape. Delay/100 seconds must expire
before the display
of the next image. The default is no delay between each showing of the
image sequence. The maximum delay is 65535.
|
|
You can specify a delay range (e.g. -delay 10-500) which sets the
minimum and maximum delay.
|
| vertical and horizontal resolution in pixels of the image |
|
This option specifies an image density when decoding a PostScript
or Portable Document page. The default is 72 dots per inch in the horizontal
and vertical direction. This option is used in concert with -page.
|
|
This is the number of bits in a pixel. The only acceptable
values are 8 or 16. Use this option to specify the depth of raw images whose
depth is unknown such as GRAY, RGB, or CMYK, or to change the depth of any
image after it has been read.
|
| reduce the speckles within an image |
| specifies the X server to contact |
|
Here are the valid methods:
|
0 No disposal specified.
1 Do not dispose between frames.
2 Overwrite frame with background color from header.
3 Overwrite with previous frame.
| apply Floyd/Steinberg error diffusion to the 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 option.
|
|
The -colors or -monochrome option is required for this option
to take effect.
|
|
Use +dither to render Postscript without text or graphic aliasing.
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| detect edges within an image |
|
Good order values are odd numbers from 3 to 31.
|
| apply a digital filter to enhance a noisy image |
| use this type of filter when resizing an image |
|
Use this option to affect the resizing operation of an image (see
-geometry).
Choose from these filters:
|
Point
Box
Triangle
Hermite
Hanning
Hamming
Blackman
Gaussian
Quadratic
Cubic
Catrom
Mitchell
Lanczos
Bessel
Sinc
|
The default filter is Lanczos
|
|
reflect the scanlines in the vertical direction.
|
|
reflect the scanlines in the horizontal direction.
|
| use this font when annotating the image with text |
|
You can tag a font to specify whether it is a Postscript, Truetype, or OPTION1
font. For example, Arial.ttf is a Truetype font, ps:helvetica
is Postscript, and x:fixed is OPTION1.
|
| define the foreground color |
|
-frame
<width>x<height>+<outer bevel width>+<inner bevel width>
|
| surround the image with an ornamental border |
|
See X(1) for details
about the geometry specification.
|
|
The color of the border is specified with the
-mattecolor command
line option.
|
| level of gamma correction |
|
The same color image displayed on two different workstations may look different
due to differences in the display monitor. Use gamma correction to adjust
for this color difference. Reasonable values extend from 0.8 to
2.3.
|
|
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).
|
|
Use +gamma value
to set the image gamma level without actually adjusting
the image pixels. This option is useful if the image is of a known gamma
but not set as an image attribute (e.g. PNG images).
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|
-geometry <width>x<height>{+-}<x offset>{+-}<y offset>{%}{@}{!}{<}{>}
|
| preferred size and location of the Image window. |
|
See X(1) for details
about the geometry specification. By default, the window size is the image
size and the location is chosen by you when it is mapped.
|
|
By default, the width and height are maximum values. That is, the image
is expanded or contracted to fit the width and height value while maintaining
the aspect ratio of the image. Append an exclamation point to the geometry
to force the image size to exactly the size you specify. For example,
if you specify 640x480! the image width is set to 640 pixels and
height to 480. If only one factor is specified, both the width and height
assume the value.
|
|
To specify a percentage width or height instead, append %. The image size
is multiplied by the width and height percentages to obtain the final image
dimensions. To increase the size of an image, use a value greater than
100 (e.g. 125%). To decrease an image's size, use a percentage less than
100.
|
|
Use @ to specify the maximum area in pixels of an image.
|
|
Use > to change the dimensions of the image only if
its size exceeds the geometry specification. < resizes the image
only
if its dimensions is less than the geometry specification. For example,
if you specify '640x480>' and the image size is 512x512, the image
size does not change. However, if the image is 1024x1024, it is resized
to 640x480.
|
|
Use < to change the dimensions of the image only if
its size exceeds the geometry specification. > resizes the image
only
if its dimensions is less than the geometry specification. For example,
if you specify 640x480> and the image size is 512x512, the image
size does not change. However, if the image is 1024x1024, it is resized
to 640x480.
|
|
There are 72 pixels per inch in PostScript coordinates.
|
| specify the icon geometry |
| the type of interlacing scheme |
|
Choices are: None, Line, Plane,
or Partition. The default is None.
|
|
This option is used to specify the type of interlacing scheme for raw image
formats such as RGB or YUV. None means do not interlace
(RGBRGBRGBRGBRGBRGB...), Line uses scanline interlacing
(RRR...GGG...BBB...RRR...GGG...BBB...),
and Plane uses plane interlacing (RRRRRR...GGGGGG...BBBBBB...).
Partition
is like plane except the different planes are saved to individual files
(e.g. image.R, image.G, and image.B).
|
|
Use Line, or Plane to create an
interlaced PNG or GIF or
progressive JPEG image.
|
| assign a label to an image |
|
Use this option to assign a specific label to the image. Optionally you
can include the image filename, type, width, height, or other image attribute
by embedding special format character. See -comment for details.
|
-label "%m:%f %wx%h"
|
produces an image label of MIFF:bird.miff 512x480 for an image titled
bird.miff
and whose width is 512 and height is 480.
|
|
If the first character of string is @, the image label is
read from a file titled by the remaining characters in the string.
|
|
When converting to PostScript, use this option to specify a header
string to print above the image. Specify the label font with
-font.
|
|
display image using this type. |
|
Choose from these Standard Colormap types: |
best
default
gray
red
green
blue
|
The X server must support the Standard Colormap you choose,
otherwise an error occurs. Use list as the type and display
searches the list of colormap types in top-to-bottom order until
one is located. See xstdcmap(1) for one way of creating Standard
Colormaps. |
| store matte channel if the image has one |
|
If the image does not have a matte channel, create an opaque one.
|
| transform the image to black and white |
| replace every pixel with its complementary color |
|
The red, green, and blue intensities of an image are negated.
White becomes black,
yellow becomes blue, etc.
Use +negate
to only negate the grayscale pixels of the image.
|
|
-page <width>x<height>{+-}<x offset>{+-}<y offset>{%}{!}{<}{>}
|
| size and location of an image canvas |
|
Use this option to specify the dimensions of the
PostScript page
in dots per inch or a TEXT page in pixels. The choices for a Postscript
page are:
|
11x17 792 1224
Ledger 1224 792
Legal 612 1008
Letter 612 792
LetterSmall 612 792
ArchE 2592 3456
ArchD 1728 2592
ArchC 1296 1728
ArchB 864 1296
ArchA 648 864
A0 2380 3368
A1 1684 2380
A2 1190 1684
A3 842 1190
A4 595 842
A4Small 595 842
A5 421 595
A6 297 421
A7 210 297
A8 148 210
A9 105 148
A10 74 105
B0 2836 4008
B1 2004 2836
B2 1418 2004
B3 1002 1418
B4 709 1002
B5 501 709
C0 2600 3677
C1 1837 2600
C2 1298 1837
C3 918 1298
C4 649 918
C5 459 649
C6 323 459
Flsa 612 936
Flse 612 936
HalfLetter 396 612
|
For convenience you can specify the page size by media (e.g. A4, Ledger,
etc.). Otherwise, -page behaves much like
-geometry (e.g.
-page
letter+43+43>).
|
|
To position a GIF image, use -page{+-}<x offset>{+-}<y
offset> (e.g. -page +100+200).
|
|
For a Postscript page, the image is sized as in -geometry and positioned
relative to the lower left hand corner of the page by
{+-}<xoffset>{+-}<y
offset>. Use
-page 612x792>, for example, to center the
image within the page. If the image size exceeds the Postscript page, it
is reduced to fit the page.
|
|
The default page dimensions for a TEXT image is 612x792.
|
|
This option is used in concert with -density.
|
| JPEG/MIFF/PNG compression level |
|
For the JPEG image format, quality is 0 (worst) to 100 (best). The default
quality is 75.
|
|
Quality for the MIFF and PNG image format sets the amount of image compression
(quality / 10) and filter-type (quality % 10). Compression quality values
range from 0 (worst) to 100 (best). If filter-type is 4 or less, the specified
filter-type is used for all scanlines:
|
0: none
1: sub
2: up
3: average
4: Paeth
|
If filter-type is 5, adaptive filtering is used when quality is greater
than 50 and the image does not have a color map, otherwise no filtering
is used.
|
|
If filter-type is 6 or more, adaptive filtering with minimum-sum-of-absolute-values
is used.
|
|
The default is quality is 75. Which means nearly the best compression with
adaptive filtering.
|
|
For further information, see the PNG
specification.
|
| lighten or darken image edges |
|
This will create a 3-D effect. See X(1) for
details about the geometry specification.
|
|
Use -raise to create a raised effect, otherwise use +raise.
|
| perform a remote operation |
|
The only command recognized at this time is the name of
an image file to load.
|
|
-roll {+-}<x offset>{+-}<y offset>
|
| roll an image vertically or horizontally |
|
See X(1) for details about
the geometry specification.
|
|
A negative x offset rolls the image left-to-right. A negative y
offset rolls the image top-to-bottom.
|
| apply Paeth image rotation to the image |
|
Use > to rotate the image only if its width exceeds the height.
< rotates the image only if its width is less than the
height. For example, if you specify -90> and the image size is
480x640, the image is not rotated by the specified angle. However, if the
image is 640x480, it is rotated by -90 degrees.
|
|
Empty triangles left over from rotating the image are filled with the color
defined as background (class backgroundColor). See X(1)
for details.
|
| scale image with pixel sampling |
|
See -geometry for details about
the geometry specification.
|
| image scene number or range |
|
Use this option to specify an image sequence with a single filename. See
the discussion of file below for details. |
|
-segment <cluster threshold>x<smoothing threshold>
|
|
Segment an image by analyzing the histograms of the color components and
identifying units that are homogeneous with the fuzzy c-means technique.
|
|
Specify cluster threshold as the number of pixels in each cluster
must exceed the the cluster threshold to be considered valid. Smoothing
threshold eliminates noise in the second derivative of the histogram.
As the value is increased, you can expect a smoother second derivative.
The default is 1.5. See Image Segmentation for details.
|
|
This resource specifies whether the utility should attempt use shared memory
for pixmaps. ImageMagick 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.
|
|
Use a gaussian operator of the given radius and
standard deviation (sigma).
|
|
-size <width>x<height>{+offset}
|
| width and height of the image |
|
Use this option to specify the width and height of raw images whose dimensions
are unknown such as GRAY,
RGB, or CMYK. In addition
to width and height, use
-size with an offset to skip any header information in
the image or tell the number of colors in a MAP image
file, (e.g. -size 640x512+256).
|
|
For Photo CD images, choose from these sizes: |
192x128
384x256
768x512
1536x1024
3072x2048
|
Finally, use this option to choose a particular resolution layer of a JBIG
or JPEG image (e.g. -size 1024x768).
|
| font for writing fixed-width text |
|
Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text. The default is 14 point Courier.
|
|
You can tag a font to specify whether it is a Postscript, Truetype, or
OPTION1 font. For example, Courier.ttf is a Truetype font
and x:fixed is OPTION1.
|
| name of texture to tile onto the image background |
| assign a title to the displayed image |
|
Use this option to assign a specific title to the image. This is assigned
to the image window and is typically displayed in the window title bar.
Optionally you can include the image filename, type, width, height, or
other image attribute by embedding special format characters: |
%b file size
%c comment
%d directory
%e filename extention
%f filename
%h height
%i input filename
%k number of unique colors
%l label
%m magick
%n number of scenes
%o output filename
%p page number
%q quantum depth
%s scene number
%t top of filename
%u unique temporary filename
%w width
%x x resolution
%y y resolution
\n newline
\r carriage return
-title "%m:%f %wx%h"
|
produces an image title of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.
|
| tree depth for the color reduction algorithm |
|
Normally, this integer value is zero or one. A zero or one tells display
to choose an optimal tree depth for the color reduction algorithm |
|
An optimal depth generally allows the best representation of the source
image with the fastest computational speed and the least amount of memory.
However, the default depth is inappropriate for some images. To assure
the best representation, try values between 2 and 8 for this parameter.
Refer to
quantize for more details.
|
|
The -colors or -monochrome option is required for this option
to take effect.
|
|
detect when image file is modified and redisplay. |
|
Suppose that while you are displaying an image the file that is currently
displayed is over-written.
display will automatically detect that
the input file has been changed and update the displayed image accordingly.
|
| print detailed information about the image |
|
This information is printed: image scene number; image name; image size;
the image class (DirectClass or PseudoClass); the total number
of unique colors; and the number of seconds to read and transform the image.
Refer to miff for a description of the image class.
|
|
If -colors is also specified, the total unique colors in the image
and color reduction error values are printed. Refer to quantize
for a description of these values.
|
| animate images using this X visual type |
|
Choose from these visual classes:
|
StaticGray
GrayScale
StaticColor
PseudoColor
TrueColor
DirectColor
default
visual id
|
The X server must support the visual you choose, otherwise an error occurs.
If a visual is not specified, the visual class that can display the most
simultaneous colors on the default screen is chosen.
|
| make image the background of a window |
|
id can be a window id or name. Specify root to
select X's root window as the target window.
|
|
By default the image is tiled onto the background of the target
window. If backdrop or -geometry are
specified, the image is surrounded by the background color. Refer to
X RESOURCES for details.
|
|
The image will not display on the root window if the image has more
unique colors than the target window colormap allows. Use
-colors to reduce the number of colors.
|
| write the image to a file |
If file already exists, you will be prompted as to whether it should
be overwritten.
By default, the image is written in the format that it was read in as.
To specify a particular image format, prefix file with the image
type and a colon (i.e. ps:image) or specify the image type as the filename
suffix (i.e. image.ps). See convert(1) for a list of valid image formats.
Specify file as - for standard output. If file has the
extension .Z or
.gz, the file size is compressed using with compress or
gzip
respectively. Precede the image file name with | to pipe to a system command.
If file already exists, you will be prompted as to whether it should
be overwritten.
Use -compress to specify the type of image compression.
The equivalent X resource for this option is
writeFilename (class WriteFilename).
See X Resources for details.
|