Undesirable smoothing effect and gamma problems on HDMI with Silverlight

  • Hi,
    actually we detected some problems regarding the image creation on the HDMI-output when we use Silverlight.
    The general impression is that the image is darker and it seems to be fuzzy/blurred when using Silverlight. If we generate the same image with Blit-function of the Win32API instead of Silverlight everything seems to be OK.

    Our configuration in detail:
    - ArmStone A9 QuadCore
    - SDK WEC7 from 25.11.2014
    - Kernel from 25.11.2014
    - Expression Blend 3
    - Windows Embedded Silverlight Tools Version 3.0.2845.0

    Please find the three testpattern in attachment. One is the original bitmap, one is generated with Silverlight and the third is generated with the Blit-Function of Win32API.
    The Silverlight and the WinAPI bitmaps are captured with a framegrabber on the HDMI output.

    We found out that the general impression arises with the following facts in detail, when using Silverlight:
    - thin white lines on black background will be converted to wider lines with a gray outline so they seem to be darker
    - a black/white checkerboard pattern results in a black/gray checkerboard pattern
    - color areas with one exact color are rasterized with a mixture of darker and brighter pixels
    - the gamma value is lower

    Is there a way to configure some parameters for the image generation via Silverlight to fix that problems?

    Best regards,