Re: [Paraview] png image file size - screenshot vs animation

[Utkarsh Ayachit]

I may have spoken the other way around. In any case, just hold on till
5.5 is out and this will be addressed.

Utkarsh

On Wed, Mar 28, 2018 at 1:13 PM, Stief, Alexander
 wrote:
> This does not fit my observation.
> Saving as a screenshot, I get a reasonably small png file size.
> Saving the same scene as an animation instead, I get huge png files instead 
> regardless of the image content.
>
> I tried again with a plain white scene and a resolution of 6428x3764
> File size using save screenshot (image quality 100): 85.2KiB
> File size using save animation (image quality 100): 69.3Mib
> File size using save animation (image quality 80): 327.2Kib
>
>
>
> Alex,
>
> In 5.4, save screenshot didn't compress the images at all. This was
> done simply to improve the performance since compression took
> considerable amount of time for larger images. However, it's been
> changed in 5.5 to a more sensible default for both animations and save
> screenshots.
>
> Also note, with PNG compression doesn't affect image quality since
> it's always lossless.
>
> Utkarsh
>
> On Wed, Mar 28, 2018 at 7:20 AM, Stief, Alexander
>  wrote:
>> Hi,
>>
>> PV version is 5.4.1
>> when making a png screenshot in PV with a resolution of 3840x2160, the file
>> size I get with default settings is ~1.4MB. This is due to the fact that
>> around 80% of the image are plain white space. So far, so normal.
>> However, when I create an animation and export to png images with the exact
>> same default settings for image quality, the image file size for the exact
>> same scene is ~28MB.
>> Only when I dial down the image quality manually to around 60 the file size
>> becomes similar to the png file from the screenshot. And the image quality
>> is not visibly worse than with 100% setting.
>> This must be some kind of bug, I never had this issue with previous
>> versions.
>>
>> tl;dr: png image file size differs greatly between screenshot and animation
>> with the exact same default settings.
>>
>> Regards
>> Alex
>>
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[Paraview] png image file size - screenshot vs animation

[Stief, Alexander]

Hi,

PV version is 5.4.1
when making a png screenshot in PV with a resolution of 3840x2160, the file 
size I get with default settings is ~1.4MB. This is due to the fact that around 
80% of the image are plain white space. So far, so normal.
However, when I create an animation and export to png images with the exact 
same default settings for image quality, the image file size for the exact same 
scene is ~28MB.
Only when I dial down the image quality manually to around 60 the file size 
becomes similar to the png file from the screenshot. And the image quality is 
not visibly worse than with 100% setting.
This must be some kind of bug, I never had this issue with previous versions.

tl;dr: png image file size differs greatly between screenshot and animation 
with the exact same default settings.

Regards
Alex
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