- -backdrop
- 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.
- -colormap type
- the type of colormap: 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.
- -colors value
- 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.
- -colorspace value
- the type of colorspace: 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.
- -crop <width>{%}x<height>{%}{+-}<x
offset>{+-}<y offset>
- preferred size and location of the cropped image.
See X(1) for details about the geometry
specification.
- To specify a percentage width or height instead,
append %. For example to crop the image by ten
percent on all sides of the image, use -crop 10%.
- Use cropping to apply image processing options to, or
display, a particular area of an image. Use -crop 0x0 to remove edges
that are the background color.
- The equivalent X resource for this option is
cropGeometry (class CropGeometry). See X
Resources for details.
- -delay <1/100ths of a second>x
- display the next image after pausing.
This option is useful for regulating the display of the
sequence of images. 1/100ths of a second must
expire before the display of the next image. The
default is 6/100th of a second between each frame of the image sequence.
The second value is optional. It specifies the
number of seconds to pause before repeating your animation
sequence.
- -density <width>x<height>
- 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 pixels per inch in the horizontal and vertical
direction.
- -display host:display[.screen]
- specifies the X server to contact; see X(1).
- -dither
- 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.
- -gamma value
- 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 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).
- -geometry <width>{%}x<height>{%}{+-}<x
offset>{+-}<yoffset>{!}{<}{>}
- 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 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.
- When displaying an image on an X server, <x offset>
and <y offset> is relative to the root window.
- The equivalent X resource for this option is geometry
(class Geometry). See X Resources for details.
- -interlace type
- the type of interlacing scheme: 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 GIF
or progressive JPEG image.
- -map type
- display image using this Standard Colormap 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.
- -monochrome
- transform the image to black and white.
- -remote string
- execute a command in an remote display process.
- The only command recognized at this time is the name of an image file to
load.
- -rotate degrees{<}{>}
- 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 bordercolor (class
borderColor). See X(1) for details.
- -scene value
- image scene number.
- Use this option to specify an image sequence with a
single filename. See the discussion of file below
for details.
- -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 to skip any header information in the image or tell the
number of colors in a MAP image file, (e.g. -size 640x512+256).
- -title string
- 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 scene number in the label by embedding special format
characters. Embed %f for filename, %d for directory,
%e for filename extention, %t for top of filename,
%m for magick, %w for width, %h for height,
%s for scene number, or %b for file size in kilobytes.
For example,
-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.
- -treedepth value
- Normally, this integer value is zero or one. A zero
or one tells display to choose a 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.
- -verbose
- 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.
- -visual type
- display image using this 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 X server screen is chosen.
- -window id
- set the background pixmap of this window to the
image.
- 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.
Image manipulation software that works like magic.