Comment 52 for bug 217908

Created an attachment (id=329705)
patch update - upscaling about:config pref

After testing the patch in a few environments, I discovered that the scrolling quality could be sluggish when Firefox was used on a thin client with an application server having low resources. Since we can assume that a thin client’s backend should have the minimum ressources to support mallocs without using the swap area, there should be no visible difference of usage on a thin client.

To give users control over image manipulation, I added the “browser.gdk_interpolation_threshold_percent” preference variable that allows values between 1-100 and has for effect to either use or bypass GDK image manipulations. The default value is 50% which only affects images being scaled by a factor of 50% or 200% and images with a visible portion under 50%. Lowering this value to it’s minimum (1%) would turn the feature off while using 100% will premanipulate any image overflowing it’s container.

Finally, as Joe from #gfx did mention, I added support for images upscaling with GDK to increase the image quality by also using the bilinear interpolation algorithm.