Does anyone have an opinion whether Zenphoto's image processing (caching/resizing/unsharp mask etc.) slightly degrades image quality? I ask because my images look better on my local computer than on my website. But maybe I am seeing things. If this is true, is there a way to improve displayed image quality?

Are you talking about sharpness or color? The latter is most common a problem of color profiles, except for Safari no browser can use them, so that pictures can look a little bland (Firefox 3 can too if it is told manually).

I meant color. Well I am using sRGB color space so I cannot imagine why it should be a problem. Oh well.

The pictures do not look that bad on your site, of course I don't know how they should look like...
Might have to do with the watermark overlay and the gd lib in general. Anyway, these color profile / color issues on computers can really be annoying...

@acrylian. Well I think they look very good but I was comparing to the preview in Adobe Lightroom and wondering if people experience any alteration in image quality. I suppose it is a minor point.

@acrylian. Well I think they look very good but I was simply comparing to the preview in Adobe Lightroom and wondering if people routinely experience any alteration in image quality. I suppose it is a minor point.