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ra_ps - convert RADIANCE picture to a PostScript file


ra_ps [ -b|c ][ -A|B|C ][ -e +/-stops ][ -n ncopies ] [ input [ output ] ]


Ra_ps translates a RADIANCE picture to a greyscale or color Adobe PostScript file for printing on a laser printer or importing to a page layout program. The -c option tells ra_ps to produce color output. (The default is greyscale, which may be specified explicitly with the -b option.)

The -A option specifies that the output should be in uncompressed ASCII hexstring format (the default). The -B option specifies that the output should be in uncompressed binary string format. The file size will be roughly half that of the ASCII equivalent, but some printers and especially some printer connections do not support binary transfer, so this option should be used with caution. The -C option specifies that the output should be in run-length compressed ASCII format. The file size will be one half to one tenth as large as the hexstring equivalent and can be sent over any network or by e-mail. The only disadvantage is that it will actually take longer to print on some printers, since the "readhexstring" procedure is generally faster than a custom replacement.

The -e option specifies an exposure compensation in f-stops (powers of two). Only integer stops are allowed, for efficiency. The -n option specifies the number of copies to print of this image. It is often preferable to use this option instead of the -#N option of lpr(1), since the latter often results in duplication of the input file with a large associated cost.

The output from ra_ps is designed to be compatible with the Encapsulated PostScript standard, which means that the resulting file may be incorporated into documents by page layout programs that can read in EPS files. Unfortunately, there is currently no option for generating a preview bitmap, so the image will show up on the screen as a rectangular area only.


Ra_ps assumes an output page that is 8.5 inches (21.5 cm) wide by 11 inches (28 cm) tall. The image will be centered on such a page, with 0.5 inch minimum margins on each side. If the actual output page is larger, the image will be towards the lower left corner. If the output page is smaller, part of the image may be cut in the upper right corner. If the image fits better on its side (ie. landscape mode), it will be rotated automatically.

PostScript printers are notoriously slow at printing large images, and the halftoning methods used are often inadequate for producing nice grey levels.


Greg Ward


pfilt(1), ra_bn(1), ra_pr(1), ra_pr24(1), ra_t8(1), ra_t16(1), ra_ppm(1), ra_tiff(1), ximage(1)

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RA_PS(1) RADIANCE (10/5/95) RA_PS(1)
Page 1 (printed 7/17/96)

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