I’ve been trying to edit my photos to upload to instagram in the 5:4 aspect ratio. When I apply this ratio to my crop and export with the pixel size 1080x1350, I get exactly those pixels. However, when I apply a frame with the framing module, sometimes the image is 1079x1350 or 1080x1349, event though I have specified 5:4 in the framing module as well.
The image is large enough to crop to it and I’ve tried with allow upscaling on. Is there something I’m missing or is this intentional?
‘Image information’ in the left panel has fields ‘export width’ and ‘export height.’ I assume those will give you an accurate size before you export, so you can check and adjust the crop by 1 pixel if necessary?
Rounding errors can easily cause a one pixel difference.
Even if the initial crop allows a perfect scaling, adding the frame can throw that off just enough to get the error.
Possible, but better use the zoom function while adjusting the crop. You can’t specify a crop dimension in pixels, unfortunately.
I ended up just resizing and add a row/column of white pixels in gimp as it seemed easier than messing around with it more. Even if the frame is uneven by one now it isn’t noticeable for my purposes
Which version of Darktable ?
5.6.0
I had the same problem. When I submit images to contests, one side has to be exactly a specific pixel count, otherwise they are rejected by the registration site. If it’s 1 pixel off after export from dt I usually crop again ever so slightly until I get the correct pixel count. In general after one or two trials I get it right.
Hard to say, this looks like a precision issue and we have fixed one recently in Darktable. If you have a RAW + xmp we could try to reproduce with the current dev version.
