To make better use of memory, 32-bit opaque images are
reduced to 16-bit images when Flash Player detects a 16-bit screen.
This downsampling consumes half the memory resources, and images
render more quickly. This feature is available only in Flash Player
10.1 for Windows Mobile.
Before Flash Player 10.1, all pixels created
in memory were stored in 32 bits (4 bytes). A simple logo of 300
x 300 pixels consumed 350 KB of memory (300*300*4/1024). With this
new behavior, the same opaque logo consumes only 175 KB. If the
logo is transparent, it is not downsampled to 16 bits, and it keeps
the same size in memory. This feature applies only to embedded bitmaps
or runtime-loaded images (PNG, GIF, JPG).
On mobile devices, it can be hard to tell the difference between
an image rendered in 16 bits and the same image rendered in 32 bits.
For a simple image containing just a few colors, there is no detectable
difference. Even for a more complex image, it is difficult to detect
the differences. However, there can be some color degradation when
zooming in on the image, and a 16-bit gradient can look less smooth
than the 32-bit version.