Re: [ gnuplot-Bugs-1575425 ] "with image" ignores gamma for postscript output (fwd)

[Daniel J S. <dan...@ie...>]

Daniel J Sebald wrote:

> I'm guessing that the gamma correction is part of the palette created
> in the PostScript file and the image code is not using the palette.
> I'll investigate.  May not be a quick fix.

Actually the fix might not be too bad.  Here is the issue:

    /* Color and gray scale images do not need a palette and can use
     * the 5 operand form of the image routine.
     */
    if ((color_mode == IC_RGB) || (sm_palette.colorMode == SMPAL_COLOR_MODE_GRAY) || !ps_params->color)
        five_operand_image = TRUE;
    else
        five_operand_image = FALSE;

I would like to keep the images condensed if possible.  Is there a way to tell if the grayscale is linear from within post.trm?  Or should I write a short little routine to verify it is?

I never new the default grayscale palette had gamma=1.5.  Well, now I do.

Dan