Following my previous topic, nobody has given me an answer that can help me, I'll rephrase my question to be as simple as possible.
Watch this image and you will understand my problem : img.imagesia.com/fichiers/hd/sans-titre-2-imagesia-com-hczj_imagesia-com_hd1h.png
I precise that I left 640, 480 in "Window size". Properties: puu.sh/7AjEV.png
In "Emulate" from XDK Intel, the image quality is good.
I export my game with AndroiD, not Crosswalk because it does not work.
The quality is bad on my samsung galaxy tab 2 & samsung nexus mobile (and I think all the other tablets/mobile).
How can I get the best images quality on mobile / tablets?