bpy.image['name'].pixels[0] shows wrong value #61977

New Issue

evgenvasilev · 2019-02-26T13:57:40+01:00

evgenvasilev commented

2019-02-26 13:57:40 +01:00

System Information
Operating system: ubuntu 18.04

Blender Version
Broken: 2.79b

Short description of error
Same image saved with different depths has different values printed with bpy.image['name'].pixels- [x] (much more than could be caused with changing depth).

Exact steps for others to reproduce the error

open attached test.blend
paste to console:

  bpy.image['test8.png'].pixels[0]
  bpy.image['test16.png'].pixels[0]

notice that output is 0.7372549176216125 and 0.5000087022781372 respectively, but images don't differ so much
test.blend
Don't worry if you don't notice images, their size is 1x1

**System Information** Operating system: ubuntu 18.04 **Blender Version** Broken: 2.79b **Short description of error** Same image saved with different depths has different values printed with bpy.image['name'].pixels- [x] (much more than could be caused with changing depth). **Exact steps for others to reproduce the error** 1. open attached test.blend 2. paste to console: ``` bpy.image['test8.png'].pixels[0] bpy.image['test16.png'].pixels[0] ``` 3. notice that output is 0.7372549176216125 and 0.5000087022781372 respectively, but images don't differ so much [test.blend](https://archive.blender.org/developer/F6717188/test.blend) ![test8.png](https://archive.blender.org/developer/F6717199/test8.png) ![test16.png](https://archive.blender.org/developer/F6717205/test16.png) Don't worry if you don't notice images, their size is 1x1

evgenvasilev commented

2019-02-26 13:57:40 +01:00

Added subscriber: @nthyjrn

Sebastian Parborg commented

2019-02-26 18:12:27 +01:00

Added subscribers: @brecht, @ZedDB

Sebastian Parborg commented

2019-02-26 18:12:27 +01:00

I can confirm this on 2.8 too.

You will get the same value if you change the color management setting to Raw.

@brecht Does this fall in with #54659 as the rest of the 16bit problems?

I can confirm this on 2.8 too. You will get the same value if you change the color management setting to Raw. @brecht Does this fall in with #54659 as the rest of the 16bit problems?

Brecht Van Lommel commented

2019-02-27 19:44:52 +01:00

Changed status from 'Open' to: 'Archived'

Brecht Van Lommel closed this issue

2019-02-27 19:44:52 +01:00

Brecht Van Lommel self-assigned this 2019-02-27 19:44:52 +01:00

Brecht Van Lommel commented

2019-02-27 19:44:52 +01:00

It's not really related to that. It's a weirdness in the API which we should improve once, but outside the scope of the bug tracker.

Blender loads 8-bit images in a byte buffer to keep memory low, without color space conversion. Higher bit depth images are always converted to scene linear color space in a float buffer.

So what you have are pixels in two different color spaces. image.is_float can be used to detect which type of image it is.

It's not really related to that. It's a weirdness in the API which we should improve once, but outside the scope of the bug tracker. Blender loads 8-bit images in a byte buffer to keep memory low, without color space conversion. Higher bit depth images are always converted to scene linear color space in a float buffer. So what you have are pixels in two different color spaces. `image.is_float` can be used to detect which type of image it is.

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bpy.image['name'].pixels[0] shows wrong value #61977