andreamarucci wrote:Should be interesting to find a way to have a watermarking option that doesn't interfere with the image quality; don't know if it's possible though...
Although I have known this for a while, I did some more research, and it just isn't technically/logically possible on server to render a watermark on a JPG image and re-save it as JPG without re-compressing. In many cases, using relatively low compression (high-quality jpg), you might not see any visible difference, but it will nevertheless need to recompress as JPG.
With new Html5 browsers, there does in fact exist some advanced method for adding a watermark in the upload process with library
watermarkjs. However, there would be two problems with this approach:
1. You would be forced to use the X3 upload-resize, which has debatable image-resize quality.
2. Since the original uploaded image has a watermark applied, the watermarks will inherit upon small images and thumbnails, which is not very nice.
3. If we add this to the frontend in real-time, the original non-watermarked images can still be found by advanced viewers, because it is handled by the browser/client.
The other option is to simply offer an option "watermark this image" from panel (handled by the server), that adds a watermark and recompresses the JPG. The result might be same file size with almost same visual quality, but ultimately not a preferred approach.
As you can see, it is complicated.