I noticed that images are quite degraded in Gallery Box. It seems Gallery Box is applying a strong compression to images when rendered in the browser. I have tested the images inserted directly into WordPress and I don’t see that problem. So it’s Gallery Box the issue. Can anybody help?
Thank you for your question.
You can easily change image quality by setting. You need to select the settings tab then need to adjust the image quality by thumbnail size setting.
Please see screenshot http://i.prntscr.com/dsiGHJbBR_y0o5ciVyI0Cg.png
I hope now you can improve your image quality.