Bug #10738

Some exported images completely black

Added by Kristian Niemi about 4 years ago. Updated about 4 years ago.

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Using a current build of dev-darktable, on export, I currently sometimes get completely black images. Not always, but sometimes. It is not limited to camera, exposure, or some such.

I do not know how to reproduce it --- but it does seem that opening the image in darktable and changing (for instance) cropping slightly at times solves the problem. At times not.

I've exported far larger images without a problem, and it's not about cropping the image into something smaller (that sometimes solves it), but changing the crop --- as in moving it, enlargening it or whatever.

I uninstalled darktable, removed local cache, and rebuilt it (git version 2.0rc2+40~g0d208c2-dirty).

Still same (bad) result.

Exporting file 151101_173549_Assi_ghat_01.NEF.xmp results in the black image "151101_173549_Assi_ghat_01.jpg".

I duplicated the image in darktable, and only changed area of crop --- moved the box; size is identical. And it (151101_173549_Assi_ghat_02.NEF.xmp) resulted in a "image with features" ("151101_173549_Assi_ghat_02.jpg"). Made no other changes. (Is it the cropping module that is at fault?)

The same results are reproduced each and every time I export these two images (01.NEF.xmp and 02.NEF.xmp).

From a batch of about 200 images, I've gotten this result (black image) in circa 10. I've yet to see a pattern why it happens to some, not others. (Which makes it all the more annoying.)

As NEF exceeds 39.1MB it is available here:

151101_173549_Assi_ghat_01.NEF.xmp (5.83 KB) 151101_173549_Assi_ghat_01.NEF.xmp xmp which results in black image Kristian Niemi, 11/24/2015 08:49 PM
darktable__debug-151124_1810 (232 KB) darktable__debug-151124_1810 darktable -d all (on export) Kristian Niemi, 11/24/2015 08:49 PM
151101_173549_Assi_ghat_02.NEF.xmp (5.83 KB) 151101_173549_Assi_ghat_02.NEF.xmp xmp which results in good image Kristian Niemi, 11/24/2015 08:50 PM

Associated revisions

Revision 8f02be02 (diff)
Added by Roman Lebedev about 4 years ago

Exposure iop: compute_correction(): IEEE 754. Fixes #10738.

total = 100663569 and d->deflicker_percentile = 100.0f
Result in thr = 100663576.000000
Which is bigger than total, so we never find bin.


#1 Updated by Roman Lebedev about 4 years ago

  • % Done changed from 0 to 20
  • Assignee set to Roman Lebedev
  • Status changed from New to Triaged

Nice catch!

#2 Updated by Roman Lebedev about 4 years ago

  • % Done changed from 20 to 100
  • Status changed from Triaged to Fixed

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