512.halftone 512.liberty Amanatides argc argv ascii ccir601 ccitt CHAN Chan chan chrominance CMAP cmap colormap CW e.g filename i.e infile int LIBERTY.anticlassic malloc nbytes NCHAN NTSC nul perror pfile1 pfile2 PIC Picclose picclose PICFILE Picfile picfile picfile's picfile.h picfiles Picgetprop picgetprop picpack Picputprop picputprop Picread picread picseek pictell Picunpack picunpack picwrite pid pid1 pid2 ptr RES rgb rgbaz rgbrgbrgb rgbz runcode SAMEARGS sed SHOESIZE SUNs tl usr xres Y,U,V yiq yres yuv zdepth