Images with alpha channel broken under non sRGB color space in Sequencer
Closed, ResolvedPublic


System Information
Ubuntu 17.04 - Intel Integrated Graphics

Blender Version
Broken: 2.78 - blender-2.78-80095645036-linux-glibc219-i686.tar.bz2
Worked: 2.77

Short description of error
Images with alpha channel are displayed incorrectly under any non sRGB color space (i.e. Linear, Filmic...) in Sequencer. Changing the alpha mode to Premul doesn't prevent the bug.

Exact steps for others to reproduce the error

  • Place a image with transparency over an opaque one
  • Change the Sequencer Color Space from sRGB to Linear, Filmic, RAW...


  • Working under sRGB in 2.78:

  • Broken under Linear in 2.78:

  • Working under Linear in 2.77:

Blend file


Brecht Van Lommel (brecht) triaged this task as Confirmed priority.Jul 16 2017, 1:30 AM

Confirmed, looks as if premultiplied alpha is not being taken into account properly when doing the color space conversion.

Sergey Sharybin (sergey) closed this task as Resolved.Sep 13 2017, 3:54 PM
Sergey Sharybin (sergey) claimed this task.

This issue was already fixed by 71f0c32dad8.

Thanks for the report anyway!