# defective png screenshots by SaveScreenshot of pvpython

**URL:** https://discourse.paraview.org/t/defective-png-screenshots-by-savescreenshot-of-pvpython/12422
**Category:** ParaView Support
**Created:** [June 30, 2023, 5:49pm UTC](https://discourse.paraview.org/t/defective-png-screenshots-by-savescreenshot-of-pvpython/12422 "2023-06-30T17:49:34Z")
**Posts on this page:** 5
**Page:** 1

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### Author: ![cfd\_ow](https://discourse.paraview.org/user_avatar/discourse.paraview.org/cfd_ow/32/9715_2.png) [@cfd\_ow](https://discourse.paraview.org/u/cfd_ow)
#### Post date: [June 30, 2023, 5:49pm UTC](https://discourse.paraview.org/t/defective-png-screenshots-by-savescreenshot-of-pvpython/12422/1 "2023-06-30T17:49:35Z")

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Have anyone seen such defective png files exported by Paraview?  
The problem is that the exported png files by SaveScreenshot of pvpython are defective. Some pixels have wrong rendering. Also, this problem seems to be related to the hardware. I ran the same python script by the same version of pvpython on another machine, the png file looks good. I post the defective and healthy png files for comparison:

 ![mpp_good](https://discourse.paraview.org/uploads/default/original/2X/a/aea5639f3ab2661db98277d5209b8e386ecf3b34.jpeg)  
 ![mpp_bad](https://discourse.paraview.org/uploads/default/original/2X/1/17648799935fa5fe48c27c11054e30c29caeaa4b.jpeg)

The information on my machine, which generated the defective png files:

> OS: Ubuntu 20.04.3 LTS  
> Version of Paraview: ParaView-5.11.0-egl-MPI-Linux-Python3.9-x86\_64  
> Graphics card: Nvidia data center GPUs (not gaming cards)

Another information is that the Osmesa version of Paraview could generate good png files but it is much slower than the above egl version, so I won’t want to use osmesa version.

The above 2 machines mentioned have the same hardware and libs, but they generate good and bad png files respectively. I know that it is very hard to replicate this issue on other machines. If anyone has encountered this issue before, it would be helpful to give me some suggestions to try. Thank you.

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [July 3, 2023, 5:05am UTC](https://discourse.paraview.org/t/defective-png-screenshots-by-savescreenshot-of-pvpython/12422/2 "2023-07-03T05:05:43Z")

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Hi @cfd_ow

To me that looks like a faulty hardware or faulty driver, you may want to run generic rendering test to validate that.

Best,

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### Author: ![cfd\_ow](https://discourse.paraview.org/user_avatar/discourse.paraview.org/cfd_ow/32/9715_2.png) [@cfd\_ow](https://discourse.paraview.org/u/cfd_ow)
#### Post date: [July 3, 2023, 2:14pm UTC](https://discourse.paraview.org/t/defective-png-screenshots-by-savescreenshot-of-pvpython/12422/3 "2023-07-03T14:14:15Z")

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Hi @mwestphal , thanks. Do you know how to run generic rendering test? Is it included in Paraview source code?

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [July 4, 2023, 9:35am UTC](https://discourse.paraview.org/t/defective-png-screenshots-by-savescreenshot-of-pvpython/12422/4 "2023-07-04T09:35:29Z")

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glxinfo, glxgears. Tools not related to ParaView.

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### Author: ![cfd\_ow](https://discourse.paraview.org/user_avatar/discourse.paraview.org/cfd_ow/32/9715_2.png) [@cfd\_ow](https://discourse.paraview.org/u/cfd_ow)
#### Post date: [July 13, 2023, 3:37pm UTC](https://discourse.paraview.org/t/defective-png-screenshots-by-savescreenshot-of-pvpython/12422/5 "2023-07-13T15:37:09Z")

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Thanks.