DPYIMAGE 1D 02 April 2001 NIST NFIS Reference Manual dpyimage displays the image contents of Baseline JPEG, Lossless JPEG, WSQ, IHead, and raw pixmap files. dpyimage options image-file -r w,h,d,wp -A -s n -a n -v -x -b n -N n -O -k -W n -H n -X n -Y n -n -T title -t -D dir -d display Dpyimage reads various image file formats, decompresses and reconstructs pixmaps as needed, and displays image contents in an X11 window. Supported file formats include Baseline JPEG (lossy), Lossless JPEG, WSQ (lossy), NIST IHead, and raw pixmap files. Raw pixmaps containing either grayscale or interleaved RGB color pixels are supported. This utility automatically differentiates between these different formats. If only one file (or the -n option) is specified on the command line, the image or images are simply read from disk and then displayed. If multiple files are specified, dpyimage attempts to minimize the display waiting time by forking a background process to pre-read images from disk. By default, the child transfers images to the parent via a pipe. This always allows at least one image to be read in from disk while the user is viewing the current image. Since a process writing on a pipe is blocked (until a read on the other end of the pipe) after transferring four kilobytes, the child will only be one image ahead of the parent except when handling smaller images. If the -t option appears on the command line, the processes use temporary files as the means of exchanging image data. Therefore, the child is not constrained on the number of images it may pre-read for the parent. However, the filesystem on which the directory for temporary files resides must have enough space for copies of all images in uncompressed state or an error may occur. This is the suggested mode for viewing compressed images for which decompression takes considerably longer than disk I/O. If the image is too large to be displayed on the screen, the upper lefthand corner will be displayed and the rest of the image can be moved into view by holding down a mouse button, moving in the direction desired, and then releasing the button. Button presses when another button(s) is already down and button releases when another button(s) is still down are ignored. Users may exit from the program by striking keys 'x' or 'X'. Advancing to the next image is accomplished by any other keystroke. -r w,h,d,wp raw pixmap attributes: w - pixel width, h - pixel height, d - pixel depth, wp - white pixel value bi-level wp=0|1 grayscale wp=0|255 RGB wp=0 (value ignored) -A automatically advances through images. -s n in automatic mode, sleeps n seconds before advancing to the next image [2]. -a n sets drag accelerator to n — changes in pointer position will result in n shifts in the displayed image [1]. -v turns on verbose output. -x turns on debug mode, causing a core dump when an X11 error occurs. -b n sets border width to n pixels [4]. -N n the child I/O process is niced to level n. -O overrides the redirect on windows (no window manager). -k informs utility that there is no keyboard input. -W n displays image in a window of width n pixels. -H n displays image in a window of height n pixels. -X n positions image window with top-left corner n pixels to the right of the display's top-left corner [0]. -Y n positions image window with top-left corner n pixels below the display's top-left corner [0]. -n does not fork to display multiple images. -T title sets window name to title [file]. -t uses temporary files to transfer multiple images to parent [via pipe]. -D directory creates temporary files in directory [/tmp]. -d display connects to alternate display. image-file ... one or more image files whose pixmaps are to be displayed. If the environment variable TMPDIR is set and the -D option is not set on the command line, dpyimage uses this directory as the location for temporary files. From test/imgtools/execs/dpyimage/dpyimage.src: % dpyimage -r 500,500,8,255 ../../data/finger/gray/raw/finger.raw displays a fingerprint image from a raw pixmap file. % dpyimage ../../data/finger/gray/jpegl/finger.jpl displays a reconstructed fingerprint image from a Lossless JPEG file. % dpyimage ../../data/finger/gray/wsq/finger.wsq displays a reconstructed fingerprint image from a WSQ file. % dpyimage ../../data/face/gray/jpegb/face.jpb displays a reconstructed grayscale face image from a Baseline JPEG file. % dpyimage -r 768,1024,24,0 ../../data/face/rgb/raw/intrlv/face.raw displays a color face image from a raw pixmap file. % dpyimage ../../data/face/rgb/jpegb/face.jpb displays a reconstructed color face image from a Baseline JPEG file. % dpyimage ../../data/face/rgb/jpegl/face.jpl displays a reconstructed color face image from a Lossless JPEG file. an2ktool(1C), cjpegb(1D), cjpegl(1D), cwsq(1D), djpegb(1D), djpegl(1D), dpyan2k(1C), dwsq(1D) NIST/ITL/DIV894/Image Group