imageapi provides a 'desaturate' option, that's used by imagecache and causes a bug in imagecache_actions see http://drupal.org/node/291925
This is because imageapi-imagemagick is actually converting to the greyscale colourspace instead of truly desaturating the image. If instead of using:
-colorspace GRAY
we use modulate (which accepts three parameters: brightness, saturation, hue) and leave the brightness alone whilst reducing the saturation to 0 and ignoring hue:
-modulate 100,0
all is ok.
Which is not to say that a true greyscale option isn't desirable, but it's not the same as desaturate. Patch to follow.
| Comment | File | Size | Author |
|---|---|---|---|
| #1 | imageapi-issue_291928-desaturate.patch | 364 bytes | adrinux |
Comments
Comment #1
adrinux commentedAh, I spoke too soon. All is not ok with this patch, it only works for jpg files in my testing, not png. I would guess it's tied up with the default colourspace for a particular image format and is a lot more complicated than I first thought :(
Patch applies to both 6.x and 5.x but obviously needs more work.
Comment #2
adrinux commentedMore to the point this still doesn't fix the problem with imagecache_actions colorshift. So now I'm just confused and feel like deleting this whole issue :(
Comment #3
adrinux commentedClosing this because I can't figure out where to take it from here.