PROCESSING(1) COMMAND REFERENCE PROCESSING(1) NAME processing - perform corrections and user-selected alterations to a GRF screen_data file SYNOPSIS processing [ -h ] [ -o device ] [ -C local|none ] [ -B local|none ] [ -G local|none ] [ -I local|color1=color2|none ] [ -D [rotate:]matrix_size[:local] ] [ -b border_color ] [ -f forms ] [ -M colormap_file ] [ -d dither_file ] [ -g gamma_file ] DESCRIPTION The processing command does picture image processing on Generic Raster Format (GRF) files; it takes a GRF screendata file, makes it suitable for color printing, and produces a GRF copydata file. The processing command performs both required and optional functions, including dithering, intensity and color corrections, and adding picture borders; it adds or modifies some GRF tags to reflect data changes it makes. Other options are turned into printer commands by the GRF protocol drivers (tcprdrv_Tek.4692(8mdqs), tcprdrv_Tek4693D(8mdqs), and tcprdrv_Tek.4696(8mdqs)) that send output to a color printer. The functions of this program are largely under user control. Vital file information such as the scan size, color map, color units and field widths are obtained from the GRF header, normally written by the screencopy command (see screencopy(1)). Optional and user-alterable parameters are specified on the command line. The GRF screendata input file is read from standard input. The GRF copydata output file is written to standard output. The processing command acts as a filter by reading in the GRF header from the image file and adding or changing GRF tags based on user-supplied command line arguments. The resulting set of GRF tags are interpreted to process the image file. GRF tags that result in processing are deleted from the header when the image file is written out. GRF tag parameter values not recognized by the processing command are not interpreted and passed on in the header. For more information on GRF headers and tags, see grf(5). The following set of GRF tags and parameters process the image file: colorcorrection {local} Performs built-in color correction. A colorcorrection Printed 5/19/88 1
PROCESSING(1) COMMAND REFERENCE PROCESSING(1) tag value other than local passes on in the GRF header of the copydata output file for interpretation by a GRF protocol driver. Color correction matches the screen colors to the ink colors of the printer. blackcorrection {local} Performs built-in black correction. A blackcorrection tag value other than local is passed on in the GRF header of the copydata output file for interpretation by a GRF protocol driver. Black correction matches gray levels of the screen to the grays of the printer. gammacorrection {local|[d,256]|[d,3,256]} Performs built-in gamma correction using a table of 256 gamma intensity values. A gammacorrection tag value of local uses a table of default gamma intensity values found in the default file /usr/lib/tcpr/tcprgamma or specified by the -g command line option. A table of gamma intensity values can also be included by a GRF tag gammacorrection [d,256] followed by a 256 entry table of gamma intensity values or a gammacorrection [d,3,256] followed by three 256 entry tables, one for each primary. Any other tag value for gammacorrection is passed on in the GRF header of the copydata output file. Gamma correction matches the intensity of the screen to the color printer. ditheringmatrix {[rotate90]localnxn|[rotate90][d,n,n]} Performs built-in ordered dithering using the specified matrix of size n. The dither matrix size n can be 2, 4, 8, or 16 which corresponds to a 2 by 2, 4 by 4, 8 by 8, or 16 by 16 square matrix used in the dithering process. The various matrix sizes allow for the tradeoff between the truer colors obtained with a larger dither size and the finer detail of a smaller dither size for an image. The dithermatrix tag value local reads a matrix of size n read from the default file /usr/lib/tcpr/tcprdither. A dither matrix can also be included by using the GRF tag dithermatrix [d,n,n]. Dither patterns can be rotated 90 degrees by prepending the GRF tag value with rotate90. An alternate file of dithering matrices can be specified by the -d command line option. invertbw {local|color1=color2} Performs built-in inversion of any two color pixels. The tag value local inverts black and white pixels. Text is best reproduced on paper as black letters on a white background, whereas it is frequently displayed on Printed 5/19/88 2
PROCESSING(1) COMMAND REFERENCE PROCESSING(1) terminal screens as white letters on a black background. Black and white pixel inversion prints white letters displayed on the terminal screen as black letters on the color printer. Color values are swapped using the color1=color2 tag value. The processing command recognizes, at a minimum, the colors red, green, blue, cyan, magenta, yellow, white and black. Additional colors can be defined in the header of the image file. An invertbw tag value other than the two described is passed on in the GRF header of the copydata output file. bordercolor {red|green|blue|cyan|magenta|yellow| white|black|none} Places a border of a specific color, or no border, around the color image. The bordercolor GRF tag is interpreted by the processing command only and has no meaning to the GRF protocol drivers. A white border places white pixels around the image, making the edges white if on paper and clear if on a transparency. Other border color values create a border by filling all unused image border with the specified color value. A black border is best when making transparencies for an overhead projector. The default is none. It specifies no border. This is the same as specifying white, except the image border is not filled in. OPTIONS -h Generates a help message containing additional information on the processing command line options and their parameter values. -o device Overrides the destinationdevice GRF tag in the GRF header of the screendata image file. This tag specifies the type of output device-dependent processing performed on the GRF image file. Valid output devices are the following Tektronix color printers: 4693d, 4692, and 4696. -C local|none Enables (local) or disables (none) the local built-in color correction function. This overrides the GRF tag colorcorrection found in the GRF header of the Printed 5/19/88 3
PROCESSING(1) COMMAND REFERENCE PROCESSING(1) screendata input file. If this option is not used the default is specified by the colorcorrection GRF tag entry in the input file. If no colorcorrection tag is found the default is none. -B local|none Enables (local) or disables (none) the local built-in black correction function. This overrides the GRF tag blackcorrection in the GRF header of the screendata input file. If this option is not used the default is specified by the blackcorrection GRF tag entry in the input file. If no blackcorrection tag is found the default is none. -G local|none Enables (local) or disables (none) the local built-in gamma correction function. This overrides the GRF tag gammacorrection found in the GRF header of the screendata input file. If this option is not used the default is specified by the gammacorrection GRF tag entry in the input file. If no gammacorrection tag is found it defaults to none. -I local|color1=color2|none Enables or disables color pixel inversion, excluding the image border. This overrides the GRF tag invertbw in the GRF header of the screendata input file. The local option enables black and white pixel inversion. The color1=color2 option enables color pixel inversion. Valid colors are red, green, blue, cyan, magenta, yellow, white, and black. If this option is not used the default is specified by the invertbw GRF tag entry in the input file. If no invertbw tag is found it defaults to none. -D [rotate:]matrix_size[:local] Specifies the size of the n by n matrix to use in the local ordered dithering. This overrides the GRF tag ditheringmatrix found in the GRF header of the screendata input file. The dither matrix_size parameter can be 2, 4, 8, or 16 which corresponds to a 2 by 2, 4 by 4, 8 by 8, or 16 by 16 matrix. A dither matrix_size of 0 disables all dithering. If this option is not used the default is specified by the ditheringmatrix GRF tag entry in the input file. If no ditheringmatrix tag is found it defaults to no dithering. -b border_color Specifies the border color, or no border, to place Printed 5/19/88 4
PROCESSING(1) COMMAND REFERENCE PROCESSING(1) around the image. Overrides the GRF tag bordercolor found in the GRF header of the screendata input file; border_color values are red, green, blue, cyan, magenta, yellow, white, black, or none. If this option is not used the default is specified by the bordercolor GRF tag entry in the input file. If no bordercolor tag is found it defaults to none. -f forms Specifies the media forms for the GRF image file. The forms type is needed to place the border around the image. Valid forms must correspond to the printer type the image is processed for and is found in the tcprforms file (see tcprforms(5)). -M colormap_file Specifies an alternate file to read in the color map for the GRF image; it replaces the existing color map. The colormap_file must be a GRF file containing the colormap and colorunits GRF tags to describe the color map. -d dither_file Specifies an alternate file of ordered dithering matrices. This file replaces the default file used by the processing command. The dither_file must be a GRF file containing a set of ditheringmatrix GRF tags to describe a set of 2 by 2, 4 by 4, 8 by 8, or 16 by 16 ordered matrices. -g gamma_file Specifies an alternate file of gamma intensity correction. This file replaces the default file used by the processing command. The gamma_file must be a GRF file containing the GRF tag entry gammacorrection [d,256] followed by a table of 256 gamma intensity values or a gammacorrection [d,3,256] tag followed by three 256 entry tables, one for each primary. EXAMPLES The following example reads the GRF screendata file file1 from standard input, processes it based on the GRF tags found in the input stream, and writes the processed GRF copydata file to file2 using standard output. processing <file1 >file2 The following example does local color and gamma correction on the GRF screendata input file file1 and places a black border around the image; the resulting copydata output file is spooled to the color printer using the tcpr command. These options override the GRF tags found in the input file. Printed 5/19/88 5
PROCESSING(1) COMMAND REFERENCE PROCESSING(1) processing -C local -G local -b black <file1 | tcpr The following example processes the screendata input file file1 with a 16 by 16 ordered dithering matrix read from the file /usr/johns/ditherfile, instead of from the default file, /usr/lib/tcpr/tcprdither. processing -D 16 -d /usr/johns/ditherfile <file1 >file2 FILES /usr/lib/tcpr/tcprdither Contains the processing command's default set of ordered dithering matrices. The file contains entries for 16 by 16, 8 by 8, 4 by 4, and 2 by 2 ordered matrices. The matrices in this file give good results on Tektronix color printers. /usr/lib/tcpr/tcprgamma Contains the processing command's default gamma intensity correction values. The gamma intensity values in this file give good results when doing gamma correction for Tektronix 410X series color terminals. /usr/lib/tcpr/tcprforms Contains the valid set of tcpr media forms for all valid Tektronix color printers. stdin Image input is a GRF screendata file. stdout Image output is a GRF copydata file. RETURN VALUE [NO_ERRS] Command completed without error. [USAGE] Incorrect command line syntax. Execution terminated. [NP_WARN] An error warranting a warning message occurred. Execution continues. [NP_ERR] An error occurred that was not a system error. Execution terminated. [P_WARN] A system error occurred. Execution continues. See intro(2) for more information on system errors. Printed 5/19/88 6
PROCESSING(1) COMMAND REFERENCE PROCESSING(1) [P_ERR] A system error occurred. Execution terminated. See intro(2) for more information on system errors. DIAGNOSTICS The processing command can issue more than 50 different error messages, mostly for bad parameter syntax and erroneous input values. SEE ALSO grf_compress(1), grf_expand(1), screencopy(1), st_grf(1), x_grf(1), tcpr(1mdqs), tchc(4), grf(5), tcprdither(5), tcprforms(5), tcprgamma(5), mdqsd(8mdqs), tcprdrv_Tek4692(8mdqs), tcprdrv_Tek4693D(8mdqs), tcprdrv_Tek4696(8mdqs), and tcprserver(8mdqs). REFERENCES For more information, consult the Users Manual for your system. Printed 5/19/88 7
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