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PICFILE(5) File Formats Manual PICFILE(5) NAME picfile - raster graphic image format DESCRIPTION Files in this format store images represented as two-dimensional arrays of multiple-channel pixels. A picfile consists of an ASCII header fol- lowed by binary data encoding the pixels in row-major order. The header is a list of attribute/value pairs separated by newlines, termi- nated by an empty line. Each header line has the form name=value. The name may not contain an ASCII NUL, newline or the value may not contain null or newline. The last line of a header is empty. The standard attributes are described below; all but TYPE and WINDOW are optional. TYPE must come first; otherwise order is irrelevant. As any unrecognised attribute is passed over uninterpreted by all standard software, applications are welcome to include arbitrary annotations, like SHOESIZE=10, if they wish. TYPE=type How the pixels are encoded. Standard types are runcode A run-length encoding. The data are a sequence of (nchan+1)-byte records each containing a count k and nchan bytes giving a pixel value to be repeated k+1 times. A run may not span scanlines. dump A two-dimensional array of nchan-byte records in row ma- jor order. bitmap One-bit pixels, packed into bytes high bit leftmost. Zero bits are white, one bits are black. Rows are padded with zeros to a multiple of 16 bits. ccitt-g4 A black-and-white image under CCITT FAX Group 4 compres- sion. This format is highly compressive on images of text and line art. Similarly, and for Group 3, 1-D and 2-D. pico A sequence of nchan two-dimensional arrays of single bytes. ccir601 Pixels are in dump order, 2 bytes per pixel encoded ac- cording to the IEEE digital component video standard. WINDOW=x0 y0 x1 y1 The x,y coordinates of the upper left corner and the point just diagonally outside the lower right corner, x increasing to the right, y down. NCHAN=nchan The number of channels, default 1. CHAN=value The order of channels. RES=x y The digitizing resolution horizontally and vertically, in pix- els/inch. CMAP= (The value is empty.) A color map, a 256x3-byte translation ta- ble for color values, follows the header. In a full-color pic- ture, each color-map row maps pixel values of the corresponding channel. In a monochrome picture, pixel values index the color map to yield red, green and blue, like this: unsigned char cmap[256][3]; red=cmap[pixel][0]; green=cmap[pixel][1]; blue=cmap[pixel][2]; EXAMPLES sed '/^$/q' image Print a header. A sample header follows. TYPE=dump WINDOW=0 0 512 512 NCHAN=1 CHAN=m RES=300 300 CMAP= COMMAND= antiquantize 'halftone CLASSIC' 512.halftone LIBERTY.anticlassic COMMAND= halftone CLASSIC 512.liberty 512.halftone 1.75 512.halftone COMMAND= transpose IN OUT COMMAND= resample 512 IN OUT COMMAND= transpose IN OUT COMMAND= resample 512 IN OUT COMMAND= clip 400 400 LIBERTY OUT SEE ALSO bcp(1), cscan(1), imscan(1), pico(1), flicks(9.1), mugs in face(9.7), rebecca(9.1), flickfile(9.5) T. Duff, `The 10th Edition Raster Graphics System', this manual, Vol- ume 2 PICFILE(5)