Compositor altering images anti aliasing Compositor is altering the colors and anti aliasing of images. I have outputed 2 image sequences in png highest quality. One opengl and one freestyle render with alpha transparency. 

When combining those image sequences in Blender (simple image sequence node with alpha over) the compositor is altering the freestyle image on load. It is altering the line thickness and some white lines (on the blue crystal) are appearing thicker and jagged now. If using the same input in photoshop the white lines appear correct and are way thinner. 

Any insight on this problem? I have the feeling it is something with transparency.

Blender composer output


Photoshop output
The worthless format known as PNG.

Render using half float 16 bit EXR.

The issue is crappy unassociated alpha that is enforced with that abysmal format known as PNG. You could also use the "Convert Premul" option to properly associate the alpha channel.