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pnminvert - invert a PNM image |
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pnminvert [pnmfile] |
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This program is part of Netpbm(1). pnminvert reads a PNM image as input, inverts it black for white, and produces a PNM image as output. If the image is grayscale, pnminvert replaces a pixel with one of complementary brightness, i.e. if the original pixel has gamma-adjusted gray value G, the output pixel has gray value maxval - G. If the image is color, pnminvert inverts each individual RGB component the same as for a grayscale image. |
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pnm(1) |
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Copyright (C) 1989 by Jef Poskanzer. |