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Strange outline when resizing white on white clips


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I'm trying to make an effect with making a image small then big via key-framing. Now, normally that wouldn't be a problem, but take a close look at this video. The intended effect is for it to be a completely white space, then have it fade into place. However, that effect is ruined by a small bug.

You can clearly see the outline of the image, despite it being a pure white image except for the fading effect in the middle. I've tried this with different clips in a completely separate project, and I only notice a problem with white on white images. I've tried reinstalling the program, but it doesn't work. I even tried cropping the image a little bit, no results. I'm on v6.31, on Windows 10 Pro 1809. This bug appears no matter what settings I have the preview/output set to.

Please let me know if any of you can reproduce this bug, or if there's any fix for this.

Edited by CommenterOfComments
for some reason i didn't add the 1 in 6.31
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For convenience of testing, I've created a project file that you can just open and see if the preview bugs out. No additional assets required.

https://drive.google.com/file/d/14aX3yzOWxbStdtRq92MPskVw8GPmqHBX/view

If any of you also get this, please let me know. I honestly don't have a clue if this is something on my end or not.

Edited by CommenterOfComments
broken link
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Sorry about that, for some reason it decided to have an older link instead of the newer one I had made. The visible link was correct, but the actual embedded link was incorrect. Should be fixed now.

Edited by CommenterOfComments
elaborated further
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HI

The outline in grey a  pixel or so wide is visible in the expanding rectangle. Something like this was reported a year or more ago but I think it was associated then with using a png transparent image but may have a similar origin. 

In this case it seems to be due (and its only thought) to the way VP calculates and retains the rectangle in a central position as it reduces in size. An accurate centre is not always achieved with every frame and one or two (or sometimes all) sides (edges) of the rectangle are left with some pixels not white or half transparent (the overlay's background is transparent) Because of this a grey line becomes visible.

You may notice this more easily if you step through the preview a frame at a time at high res, the line appears on different sides in each frame. As I said it's possibly something to do with the way VP keeps the overlay  central. I don't know if NCH will come in with a better (or correct) answer or even if it is something that can be cured.

Nat.

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Hi

The artifact you mention is visible and I notice you are using png files with a transparent background. These had a problem as I mentioned. Not sure how it was resolved. It is also seen with a ,jpg (made as same image but no transparency) and a transparent .gif. NCH may comment.

If you shift the white blank along track 1 and the logo along tracks 3 and 4 and then drag the cursor line along the sequence you can see the grey edges of the expanding png frame of the graded circle against the black "no image video track 1" quite easily. Different sides appear depending on the size of the the rectangle

aa.jpg

It has something to do with the way VP reduces the outline of the  transparent png but no idea how to prevent it.

Nat

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Hi

Tried different things but the grey line persists.  As this is tied to the use of SCALE or other effects that incorporate SCALE use ZOOM

This is how you can do it......

To make things a little simpler it's not necessary to use a transparent .png of your graded circle  You can use a  . jpg of suitable size. **

  • Create a much smaller image of your graded circle on a white background as a normal jpg  Its initial size should be the same apparent size as your starting circle in the  .png before your scale effect was added.**   Put this  image clip on Track 2 in place of your ,png image clip
  • Adjust its duration to that the original. (Same length as the clip on Video Track 3)
  • Now add a ZOOM effect to the graded circle image on Track 2 so that it expands to the desired size at the correct point. The zoom rectangle should start full frame be reduced so it finishes up just outlside the graded circle as shown here.....
  • ss.jpg
  • Instead of FADE at the end of this use the TRANSPARENCY effect with keyframes to get the circle image to fade just as it has filled the large C as here..........
  • vv.jpg

ww.jpg

This is the VP screen above with the .jpg on Video Track 2.

** Using a 1280 x 720 frame your graded circle would be 146 pixels across.

There will be no borders visible during the zoom-in.(As there are  no borders!)

Best of luck

Nat

 

 

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