Several times a week on this forum, people ask how to reduce flicker in still photos that are moved using pan/crop. I have a huge project with over 1,000 still photos, and I wanted to make sure, before I rendered, that I was doing everything correctly. I found the worst photo of the bunch -- worst in terms of the artifacts created when using pan/crop to move it -- and then tried all sorts of things to eliminate the problems.
This is not an exhaustive test. I'm sure the results will depend on the source material, file format, render type, and many other variables. However, you may find the results useful.
I took my test photo and created some pan/crop moves (zoom, diagonal move, rotation). I then duplicated this and then tried various things, one at a time. Here are the things that made the most difference, starting with the one that made the biggest difference. I rendered to NTSC, created a DVD using DVDA, and then played through my DVD player onto a 45" television monitor.
1. Reduce resolution before importing into Vegas. This helped the most. My original file was a 1536 x 2048 JPEG image. I used "Match Output Aspect Ratio" in the pan/crop which gave me 1536x1126. If I hadn’t zoomed, then I could have reduced the resolution, using PhotoShop, by 50% and still have had enough pixels. However, since my pan/crop movements included a zoom of about 30%, I needed an image with about 30% more resolution than the 720x480 of my NTSC final output. By reducing the image to 61% of its original size (in Photoshop), I ended up with a 937 x 1249 image. This left just enough resolution to zoom in 30% and not end up with an image that had fewer pixels in either direction than 720x480.
The flicker, staircasing, and other artifacts around hard transitions from light to dark, were dramatically reduced using this technique. I didn't see any noticeable new artifacts, nor did the image seem to be degraded. One other benefit is that the lower-res files render faster.
2. Reduce Interlace Flicker. I was surprised to see that this helped quite a bit. It is definitely worth doing. I didn't see any noticeable new artifacts, nor did the image seem to be degraded. There are several scripts bouncing around various sites that automate the process of applying this attribute (I am at the moment too lazy to find the links — sorry).
3. Gaussian Blur. I applied the Gaussian Blur fX and used the smallest possible setting (0.001). This definitely helped but, even using this small amount, it slightly reduced the "edge" of the picture. I wouldn't call it soft or out of focus, but it just wasn't quite as snappy as before. I have seen a number of different suggestions about using other types of blurring, and I didn't have time to experiment with these. Perhaps someone else would like to experiment. I was less intrigued with this approach because it is obvious that the picture will be degraded. Also, rendering times using Gaussian Blur were quite a bit longer.
4. Best Rendering. When you choose "Render As" and then click the "Custom" button, the first option you see on the Project tab is "Video Rendering Quality." This is normally set to "Good." The Vegas help system has this to say about this setting: "If you're using high-resolution stills (or video) that will be scaled down to the final output size, choosing Best can prevent artifacts." Based on this, and on posts in this forum, I have been recommending to people to use the Best setting when rendering a project that contains lots of high-resolution still images. While the results were better than with good, the differences were quite subtle compared to 1-3 above, and the rendering time was MUCH longer (1:48 for good and 3:23 for best).
5. Supersampling. I have read several posts that claim the Video Bus supersampling envelope can help. I applied it to the original picture, but was unable to detect any noticeable improvement. At least in this one test case, Supersampling was a waste of time.
Conclusion For 95% of "problem" images, reducing resolution down to 720x480, multiplied by the maximum zoom you plan to use, gives you the most bang for the buck, although it requires you to spend time with each image in PhotoShop (or your favorite editor which, for me, is PhotoImpact). If you combine this with Reduce Interlace flicker, even a problem image like the one I used can be made almost artifact free. Taking the next step and using resolution reduction and reduce interlace flicker along with Best rendering gets you very close to no artifacts at all. If you absolutely must kill every last bit of flicker, then go ahead and apply some form of blur (as already noted, I used the Gaussian Blur at the 0.001 setting). All four settings together will pretty much kill flicker in any image.
One related note: As Ed Troxel noted in this thread (), you should use Pan/Crop to generate motion with images and not track motion because track motion operates at video resolution, after the still has already been down-sampled. You can easily verify this for yourself by putting the same image on two tracks, one above the other. On the top track, zoom way in on some detail in your picture using the pan/crop event setting. On the track below, use track motion. The track motion zoom will be totally blurry compared to pan/crop. For video, this problem doesn’t exist at all because video is already, by definition, at video resolution. This issue only applies when the source material is high resolution or generated by Vegas itself.
[Edit] After many people replied, it was pointed out that you only need to set the vertical amount of Gaussian blur to 0.001, and leave the horizontal setting at zero. This should provide most of the flicker reduction, without as much softening of the image.
This is not an exhaustive test. I'm sure the results will depend on the source material, file format, render type, and many other variables. However, you may find the results useful.
I took my test photo and created some pan/crop moves (zoom, diagonal move, rotation). I then duplicated this and then tried various things, one at a time. Here are the things that made the most difference, starting with the one that made the biggest difference. I rendered to NTSC, created a DVD using DVDA, and then played through my DVD player onto a 45" television monitor.
1. Reduce resolution before importing into Vegas. This helped the most. My original file was a 1536 x 2048 JPEG image. I used "Match Output Aspect Ratio" in the pan/crop which gave me 1536x1126. If I hadn’t zoomed, then I could have reduced the resolution, using PhotoShop, by 50% and still have had enough pixels. However, since my pan/crop movements included a zoom of about 30%, I needed an image with about 30% more resolution than the 720x480 of my NTSC final output. By reducing the image to 61% of its original size (in Photoshop), I ended up with a 937 x 1249 image. This left just enough resolution to zoom in 30% and not end up with an image that had fewer pixels in either direction than 720x480.
The flicker, staircasing, and other artifacts around hard transitions from light to dark, were dramatically reduced using this technique. I didn't see any noticeable new artifacts, nor did the image seem to be degraded. One other benefit is that the lower-res files render faster.
2. Reduce Interlace Flicker. I was surprised to see that this helped quite a bit. It is definitely worth doing. I didn't see any noticeable new artifacts, nor did the image seem to be degraded. There are several scripts bouncing around various sites that automate the process of applying this attribute (I am at the moment too lazy to find the links — sorry).
3. Gaussian Blur. I applied the Gaussian Blur fX and used the smallest possible setting (0.001). This definitely helped but, even using this small amount, it slightly reduced the "edge" of the picture. I wouldn't call it soft or out of focus, but it just wasn't quite as snappy as before. I have seen a number of different suggestions about using other types of blurring, and I didn't have time to experiment with these. Perhaps someone else would like to experiment. I was less intrigued with this approach because it is obvious that the picture will be degraded. Also, rendering times using Gaussian Blur were quite a bit longer.
4. Best Rendering. When you choose "Render As" and then click the "Custom" button, the first option you see on the Project tab is "Video Rendering Quality." This is normally set to "Good." The Vegas help system has this to say about this setting: "If you're using high-resolution stills (or video) that will be scaled down to the final output size, choosing Best can prevent artifacts." Based on this, and on posts in this forum, I have been recommending to people to use the Best setting when rendering a project that contains lots of high-resolution still images. While the results were better than with good, the differences were quite subtle compared to 1-3 above, and the rendering time was MUCH longer (1:48 for good and 3:23 for best).
5. Supersampling. I have read several posts that claim the Video Bus supersampling envelope can help. I applied it to the original picture, but was unable to detect any noticeable improvement. At least in this one test case, Supersampling was a waste of time.
Conclusion For 95% of "problem" images, reducing resolution down to 720x480, multiplied by the maximum zoom you plan to use, gives you the most bang for the buck, although it requires you to spend time with each image in PhotoShop (or your favorite editor which, for me, is PhotoImpact). If you combine this with Reduce Interlace flicker, even a problem image like the one I used can be made almost artifact free. Taking the next step and using resolution reduction and reduce interlace flicker along with Best rendering gets you very close to no artifacts at all. If you absolutely must kill every last bit of flicker, then go ahead and apply some form of blur (as already noted, I used the Gaussian Blur at the 0.001 setting). All four settings together will pretty much kill flicker in any image.
One related note: As Ed Troxel noted in this thread (), you should use Pan/Crop to generate motion with images and not track motion because track motion operates at video resolution, after the still has already been down-sampled. You can easily verify this for yourself by putting the same image on two tracks, one above the other. On the top track, zoom way in on some detail in your picture using the pan/crop event setting. On the track below, use track motion. The track motion zoom will be totally blurry compared to pan/crop. For video, this problem doesn’t exist at all because video is already, by definition, at video resolution. This issue only applies when the source material is high resolution or generated by Vegas itself.
[Edit] After many people replied, it was pointed out that you only need to set the vertical amount of Gaussian blur to 0.001, and leave the horizontal setting at zero. This should provide most of the flicker reduction, without as much softening of the image.