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Raw format PGM in Gimp 2.6.7

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Raw format PGM in Gimp 2.6.7 Kevin O'Gorman 12 Feb 23:52
  Raw format PGM in Gimp 2.6.7 Liam R E Quin 13 Feb 01:01
Kevin O'Gorman
2010-02-12 23:52:36 UTC (almost 15 years ago)

Raw format PGM in Gimp 2.6.7

I notice that the Gimp can read and work with PGM files in raw and plain formats so long as the grayscale formats are in the 0-255 range. However, the PGM documentation specifies a variant of the raw format in which the values may go up to 65535. I have some images like that, and the Gimp complains about an invalid "maxval". Other tools like eog(1) and Irfanview(Windows) read the images just fine. I have attached one, which may be small enough to make it through (ungzipped it's just over 37K).

Is this omission intentional?

Liam R E Quin
2010-02-13 01:01:22 UTC (almost 15 years ago)

Raw format PGM in Gimp 2.6.7

On Fri, 2010-02-12 at 14:52 -0800, Kevin O'Gorman wrote:

[...]

the PGM documentation specifies a variant of the raw format in which the values may go up to 65535.

GIMP is currently limited to 8-bit values. This is being worked on, but the work progresses slowly because there are not many gimp developers (and some of them are forced to wear shoes during the day).

The right fix is probably to wait for the gegl-based support of greater colour depths. In the meatime, you can probably use "convert" from ImageMagick or pgmtopnm to dither or approximate the images using 8 bits.

Liam