Poor quality png image

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ebody_cut

Poor quality png image

PostFri Jan 15, 2021 1:46 pm

Hi,

i use a png image with transparent background in my video. But the quality is terrible. The size is 200x200 pixel and use it a little bit smaler. I zoom the png image to scale it.

If i use the image in photoshop or drag it to a browser it´s all fine.

How do i get a clean png image into the video?

Best regards,
ebody
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Jim Simon

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Re: Poor quality png image

PostFri Jan 15, 2021 2:15 pm

What version of Resolve?
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ebody_cut

Re: Poor quality png image

PostFri Jan 15, 2021 2:18 pm

Jim Simon wrote:What version of Resolve?


16.2.8.005
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Jim Simon

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Re: Poor quality png image

PostFri Jan 15, 2021 3:06 pm

Alright.

I didn't see any image scaling issues in 16 (I do in 17), so I'm not sure what's the issue.

Just to get you moving forward, maybe scale the image in Photoshop to the correct size?
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waltervolpatto

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Re: Poor quality png image

PostFri Jan 15, 2021 4:19 pm

If you scale that in the edit page, open the inspector and set the scaling option algorithm to "softer"
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richards

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Re: Poor quality png image

PostFri Jan 15, 2021 8:48 pm

The issue is that PNG's only support Straight alpha, which means that there's hidden colour data in the transparent areas of your image - most likely black or white, but it could be anything. When you resize the image, you're stretching both the (separate) transparency and the colour data, which results in the normally-hidden colour data in the transparent areas bleeding into the non-transparent areas.

The correct solution is to use Premultiplied alpha, which PNG's do not support. If you go this route (IIRC TIFF's do support Premultiplied) but I can't remember the exact workflow to get them out of Photoshop correctly - it's a pain from memory, really hard to verify, and therefore really easy to mess up and wonder why it's not working...
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