Re: [PUSHED] Re: [PUSHED] Re: [PATCH] fdo#46378: Poor Resampling Image quality
Hi Tomaž, On 2012-06-06 at 23:22 +0200, Tomaž Vajngerl wrote: > > Great stuff - I have pushed your patch, and also my patches to default > > to Lanczos filter. Can you please add an example of "before" and > > "after" where the advantages of the Lanzcos filter are nicely visible to > > the Release Notes (http://wiki.documentfoundation.org/ReleaseNotes/3.6)? > Done. Great picture, thanks a lot! > > Adding the QA list to the CC: - thanks to Tomaz, we have changed the > > default of the image resize operations to a new scaling operation. > > Please be careful about bugs that involve scaling of images, quality of > > eg. PDF output, or speed of such operations. > Regarding bugs.. I have found a problem with creation of Bitmaps in > ImplScaleLanczos. I have fixed so the Bitmaps are created in the same > way as in ImplScaleInterpolate - the patch is attached. This problem > is visible if you go into impress and set the background of a slide to > a bitmap which is tiled. I have not found any reports in bugzilla > about this yet. Pushed :-) Actually - can you ask for push access? Your patches are consistent, look good, and you know what you are doing, so would be great if you could push them yourself. Of course in case of doubts, you can still ask for a review on the ML first. http://wiki.documentfoundation.org/Development/NewAccount Please CC: michael.me...@novell.com on the bug you create. > > Tomaz - what interests you next? :-) You've already outlined some ideas > > regarding the filters, correct? > I am working now to on blur/soften filter which uses > ImplHorizontalConvolution and ImplVerticalConvolution - which are also > used in Lanczos resampling. I have this already working with a > parameterized blur radius. Currently the soften filter only uses a > fixed 3x3 convolution matrix with 2D convolution algorithm. My > solution should be faster and more flexible than the current one. I > still need to add a dialog to select the blur radius which I will do > in step 2. > > Other ideas I have is to add "reduce image resolution" function > directly to bitmap so a user could change the image resolution not > only in PDF export but in general. When a user applies a filter, the > image is changed and saved as a new PNG image into the document. So to > create something like this should not be hard. > > In a long run I want to improve the quality of images in export but I > think this is a problem of whole page rendering and not so simple to > solve. That sounds great, should you need any code pointers, I'll be glad to help. All the best, Kendy ___ LibreOffice mailing list LibreOffice@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/libreoffice
Re: [PUSHED] Re: [PUSHED] Re: [PATCH] fdo#46378: Poor Resampling Image quality
Hi, On Tue, Jun 5, 2012 at 11:33 AM, Jan Holesovsky wrote: > Great stuff - I have pushed your patch, and also my patches to default > to Lanczos filter. Can you please add an example of "before" and > "after" where the advantages of the Lanzcos filter are nicely visible to > the Release Notes (http://wiki.documentfoundation.org/ReleaseNotes/3.6)? Done. > Adding the QA list to the CC: - thanks to Tomaz, we have changed the > default of the image resize operations to a new scaling operation. > Please be careful about bugs that involve scaling of images, quality of > eg. PDF output, or speed of such operations. Regarding bugs.. I have found a problem with creation of Bitmaps in ImplScaleLanczos. I have fixed so the Bitmaps are created in the same way as in ImplScaleInterpolate - the patch is attached. This problem is visible if you go into impress and set the background of a slide to a bitmap which is tiled. I have not found any reports in bugzilla about this yet. > Tomaz - what interests you next? :-) You've already outlined some ideas > regarding the filters, correct? I am working now to on blur/soften filter which uses ImplHorizontalConvolution and ImplVerticalConvolution - which are also used in Lanczos resampling. I have this already working with a parameterized blur radius. Currently the soften filter only uses a fixed 3x3 convolution matrix with 2D convolution algorithm. My solution should be faster and more flexible than the current one. I still need to add a dialog to select the blur radius which I will do in step 2. Other ideas I have is to add "reduce image resolution" function directly to bitmap so a user could change the image resolution not only in PDF export but in general. When a user applies a filter, the image is changed and saved as a new PNG image into the document. So to create something like this should not be hard. In a long run I want to improve the quality of images in export but I think this is a problem of whole page rendering and not so simple to solve. Regards, Tomaž 0001-Fix-new-Bitmap-creation-in-Lanczos-resampling.patch Description: Binary data ___ LibreOffice mailing list LibreOffice@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/libreoffice
[PUSHED] Re: [PUSHED] Re: [PATCH] fdo#46378: Poor Resampling Image quality
Hi Tomaz, On 2012-06-05 at 07:34 +0200, Tomaž Vajngerl wrote: > I found the problem - rescaling did not work correctly when upscaling > the image. I don't see any artifacts with this fix anymore when I use > Lanczos for all scale operations. Great stuff - I have pushed your patch, and also my patches to default to Lanczos filter. Can you please add an example of "before" and "after" where the advantages of the Lanzcos filter are nicely visible to the Release Notes (http://wiki.documentfoundation.org/ReleaseNotes/3.6)? Adding the QA list to the CC: - thanks to Tomaz, we have changed the default of the image resize operations to a new scaling operation. Please be careful about bugs that involve scaling of images, quality of eg. PDF output, or speed of such operations. Tomaz - what interests you next? :-) You've already outlined some ideas regarding the filters, correct? Thank you a lot, Kendy ___ LibreOffice mailing list LibreOffice@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/libreoffice
