Various discussion boards for XnView and related products
https://newsgroup.xnview.com/
Right, 8 bit greyscale.dma_k wrote:I have noticed that when I apply the rotation (Image → Rotate → Custom) to the 1bit (binary) image, it is converted to 8bit.
Rotation of binary pixels is possible, but not interpolation ("Smooth"). If interpolation is desired, the image must be "upgraded". There is still a flaw BTW, the image should be upgraded to 16 bit linear greyscale ... note that 8 bit linear greyscale is not feasible, and doing linear interpolation on 8 bit non-linear brightness is incorrect and causes unnecessary quality and brightness loss.That is unexpected. Is rotation not possible for binary data? It should be even more simpler
I am not sure, what you actually mean for interpolation ("smoothing") during the rotation... Could you be more verbose?DOS386 wrote:Rotation of binary pixels is possible, but not interpolation ("Smooth"). If interpolation is desired, the image must be "upgraded". There is still a flaw BTW, the image should be upgraded to 16 bit linear greyscale ... note that 8 bit linear greyscale is not feasible, and doing linear interpolation on 8 bit non-linear brightness is incorrect and causes unnecessary quality and brightness loss.
See http://newsgroup.xnview.com/viewtopic.php?t=19897 why
Try to rotate (by 30 deg maybe) with and without "Smooth" ... check the results.not sure, what you actually mean for interpolation ("smoothing") during the rotation... Could you be more verbose?
Sure, but this is a lossy conversion and might be usually a bad idea, so it's OFF for now ...In any case, the image can be automatically converted back to binary after the rotation, right?
The point where I see an urgent need for improvement is to auto convert to 16bppc (thus 64 bpp total for RGBA) linear whenever necessary to do things right (zoom (except NN)), blur, rotate (except NN AKA "non-smooth"), trapez/barrel corrections (not implemented yet), ...). I see no point to keep 1 bpp binary on rotate (except 90 deg).So what do you think: the current behaviour is OK, or it can/should be improved?
dma_k wrote:I am not sure, what you actually mean for interpolation ("smoothing") during the rotation... Could you be more verbose?
I have made a try for this image. I personally see no results for rotation without and with smoothing:DOS386 wrote:Try to rotate (by 30 deg maybe) with and without "Smooth" ... check the results.
Perhaps that could be a preference option ([x] Stay in the same color depth with rotating / zooming the image) or automatically stay in binary when smoothing is OFF?DOS386 wrote:Sure, but this is a lossy conversion and might be usually a bad idea, so it's OFF for now ...In any case, the image can be automatically converted back to binary after the rotation, right?
Link is dead but rotate works for me, I do get results and they are different. Look better or count coloursdma_k wrote:I have made a try for http://dead???files.com/files/7wot0u1d2 this image. I personally see no results for rotation without and with smoothing
That's because smoothing is only applied to the preview thumbnail, even if Apply to image is activateddma_k wrote:I personally see no results for rotation without and with smoothing:
Not all binary images are created equaldma_k wrote:XnTriq, thank you for links. I understand the principle of anliasing, but for me it makes sense only for non-binary images.
In my tests (30° clockwise w/o smoothing) the color depth of Scan001.TIF was't increaseddma_k wrote:Perhaps that could be a preference option ([x] Stay in the same color depth with rotating / zooming the image) or automatically stay in binary when smoothing is OFF?
Thank you! I have overlooked that if smoothing is off, then the color depth is not changing.XnTriq wrote:In my tests (30° clockwise w/o smoothing) the color depth of Scan001.TIF was't increased
