Merge "Fix crash when quantizing" into sc-dev

            // Note: they don't _have_ to be ignored, for example, we could instead turn them

            // opaque. Traditionally, including outside Android, quantizers ignore transparent

            // pixels, so that strategy was chosen.

            int alpha = (pixel >> 24);

            int alpha = (pixel >> 24) & 0xff;

            if (alpha < 255) {

                continue;

            }