Blackmagic Forum

If I apply a fusion transition on a cropped image, a thin black outline appears during the transition.

I created a simple project by using a screenshot image from BMD website to demonstrate the problem
Here is the download link: https://www.dropbox.com/s/ngkm49ec2re07 ... e.zip?dl=1

Here is an example GIF, if you pay attention closely, a thin outline appears on each element during the zoom animation, it's more clearly visible on the "Latest Videos" text


Edit: It happens also with non-fusion transitions, for example push transition. The problem goes away after enabling "Retain Image Position"

I've had a similar result with images where a green background has been removed. A thin surrounding line around the image still remains even after cropping. It doesn't seem that softening or additional color matching (drawing more color-to-be-removed-identifying lines...even when those lines are adjacent to the unwanted thin lines) helps at all. I had similar "unwanted frames" around green-screen removed images in Pinnacle which was one of the main reasons for trying Resolve.

Is there a workaround?

The issue seems to be that the crop occurs on the source image before it gets resized to fit your timeline, so when it does get resized Resolve blurs the alpha mask that the crop generated. If you look at the transition effect in the Fusion tab, put the Media In in the viewer, change it so only the alpha channel is visible, then zoom in - you can see the edge of the crop is blurry, which is what's generating the black outline (Resolve doesn't handle alpha compositing correctly, which is discussed in another thread).

Only workarounds I'm aware of are:

1. Change the clip's scaling to Crop in Inspector > Retime and Scaling > Scaling.
2. Set Project Settings > Image Scaling > Input Scaling to "Center crop with no resizing".

For some reason, the Resize Filter specified in both the Inspector and Project settings > Image Scaling has no effect on this, though it should (if it did, Nearest Neighbour would be another workaround, but nope)!

I think I get your instruction #2
(scroll box below down if necessary)
(I selected "Center Crop with no sizing"

but I'm confused by #1.
Is this the right place to make change #1 (if not please indicate where)


and, if the picture above shows the right place, change what fields to what?

Also, does that limit your resizing (zooming) and only allow cropping or is it just a workaround with no loss involved?
Thanks!
John

panos_mts wrote:If I apply a fusion transition on a cropped image, a thin black outline appears during the transition.

I created a simple project by using a screenshot image from BMD website to demonstrate the problem
Here is the download link: https://www.dropbox.com/s/ngkm49ec2re07 ... e.zip?dl=1

Here is an example GIF, if you pay attention closely, a thin outline appears on each element during the zoom animation, it's more clearly visible on the "Latest Videos" text


Edit: It happens also with non-fusion transitions, for example push transition. The problem goes away after enabling "Retain Image Position"

I have observed the same problem just adding a jpg over a white background in Davinci Resolve. The only fix that I found was to take the image into Paint.net, use the magic wand to turn the white areas transparent, then save it as a PNG. The thin black lines are probably still there, but since they are now at the edges of the black text its not visible. Of course this method won't work if the picture has colors that you want to save, but I just needed a jpg to fade in over a white background in the edit page.