[vtkusers] vtkAVIWriter with renderer gradient background shows distinct lines

[Cory Quammen]

Great, glad to hear it. What compression options did you settle on in
case someone runs into this issue in the future?
On Fri, Nov 30, 2018 at 8:30 AM Santosh Biradar <scbiradar at gmail.com> wrote:
>
> Thanks Cory. I was able to try different compression options and was able to remove the background lines appearing because of the gradient albeit with large size of the AVI files.
> Thanks Andras for pointing me to an alternate to vtkAVIWriter. I will explore the MKV container.
>
> Santosh
>
> On Wed, Nov 28, 2018 at 1:01 PM Andras Lasso <lasso at queensu.ca> wrote:
>>
>> In 3D Slicer we use VP9 codec with MKV container and it works well. VP9 is not as widely used as H264 but it is completely royalty-free and offers good compression ratio and acceptable speed even with lossless settings.
>>
>>
>>
>> We build required libraries (VP9, libwbm, yasm) using CMake superbuild on Windows/Linux/Mac. Container file reading/writing implementation is here: https://github.com/IGSIO/IGSIO/blob/master/Source/VideoIO/MKV/vtkMKVWriter.cxx, and VP9 codec is here: https://github.com/IGSIO/SlicerIGSIO/blob/master/VideoIO/Codecs/vtkVP9VolumeCodec.cxx.
>>
>>
>>
>> Andras
>>
>>
>>
>> From: vtkusers <vtkusers-bounces at public.kitware.com> On Behalf Of Cory Quammen
>> Sent: Tuesday, November 27, 2018 10:11 AM
>> To: santosh <scbiradar at gmail.com>
>> Cc: vtkusers <vtkusers at vtk.org>
>> Subject: Re: [vtkusers] vtkAVIWriter with renderer gradient background shows distinct lines
>>
>>
>>
>> I'm afraid I don't have a lot of experience with the AVI compression options. You might experiment with vtkAVIWriter::SetCompressorFourCC() to see if you can find a compressor that gives more satisfactory results.
>>
>>
>>
>> Personally I prefer to dump animation frames and assemble them with outside video software.
>>
>>
>>
>> Cory
>>
>>
>>
>> On Tue, Nov 27, 2018 at 9:26 AM Santosh Biradar <scbiradar at gmail.com> wrote:
>>
>> Thanks for the quick response Cory.
>>
>> I tried setting quality to 0,1,2. The quality of the movie was best for 2 and worst for 0 but the background remained the same in each case.
>>
>> The quality of the output of the  filter (in this case, a vtkContourFilter) reduces with reduction in SetQuality but the background remains of the same quality.
>>
>> There is no difference in the quality of the background.
>>
>>
>>
>> I also get the same behavior in Paraview's Save Animation feature (version 5.5 on windows)
>>
>>
>>
>> Thanks,
>>
>> Santosh
>>
>>
>>
>>
>>
>> On Tue, Nov 27, 2018 at 7:29 PM Cory Quammen <cory.quammen at kitware.com> wrote:
>>
>> Sounds like quantization/compression artifacts. You can try changing the quality setting to reduce compression via vtkAVIWriter::SetQuality().
>>
>>
>>
>> HTH,
>>
>> Cory
>>
>>
>>
>> On Tue, Nov 27, 2018 at 8:55 AM Santosh Biradar <scbiradar at gmail.com> wrote:
>>
>> I am trying to create a movie of an animation using vtkAVIWriter.
>>
>> The renderer has a gradient background. The .avi file created has distinct lines/bands in the background because of the gradient. Is it possible to get rid of these lines. I notice that if I use a vtkBMPWriter and write an image, the image seems fine without any such lines/bands.
>>
>>
>>
>> A code snippet of what I am doing:
>>
>>
>>
>> window_to_image = vtk.vtkWindowToImageFilter()
>> window_to_image.SetInput(renWin.GetRenderWindow())
>> window_to_image.SetInputBufferTypeToRGB()
>> window_to_image.ReadFrontBufferOff()
>>
>> writer = vtk.vtkAVIWriter()
>> writer.SetInputConnection(window_to_image.GetOutputPort())
>>
>> I am running python wrapper of VTK-6.3.0 on windows
>>
>>
>>
>> Thanks,
>>
>> Santosh
>>
>>
>>
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
>>
>> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>>
>> Search the list archives at: http://markmail.org/search/?q=vtkusers
>>
>> Follow this link to subscribe/unsubscribe:
>> https://public.kitware.com/mailman/listinfo/vtkusers
>>
>>
>>
>>
>> --
>>
>> Cory Quammen
>> Staff R&D Engineer
>> Kitware, Inc.
>>
>>
>>
>>
>> --
>>
>> Cory Quammen
>> Staff R&D Engineer
>> Kitware, Inc.



-- 
Cory Quammen
Staff R&D Engineer
Kitware, Inc.