PNG Transparency?
Posted Wednesday, September 23, 2009 at {ts '2018-04-23 18:22:00'}

I seem to be having loads of issues with ImageCFC.watermark and PNG transparency. I'm not sure whether it's how Photoshop (CS3) is writing the PNG, or what.

First, if I save as an 8-bit PNG, Photoshop insists on saving an indexed CLUT, which, in the case of this particular image I'm working with means a palette of only 8 or 9 colors. And this results in an error about "LUT has improper length!". I only mention that because I'll bet some other folks are having the same issue. And it's actually traced back to a bug in the java image object, so I wouldn't expect ImageCFC to be able to do anything about it.

I tried saving as a 24-bit PNG, but this seems to lose all transparency for the original image. This DOES seem to be an ImageCFC issue, because if the watermark image is 24-bit, it does NOT lose it's transparency. It's only the original (base) image.

I saved the base image as 8-bit, exploded the CLUT so there were more than 32 colors in it, and when I apply the watermark, the transparent area of the base image turns dark grey, though the watermark images retained their transparency just fine.

It looks like the base image just can't have any transparency. Is anyone else experiencing this?