Cant Render in Vegas 7.0. Not Jpeg Friendly?

[Dave Haynie]

[Bob Peterson] “Let me expand. In Photoshop, the recommended method for decreasing a photo’s size is bicubic sharper while the recommended method for increasing a photo’s size is bicubic smoother. Unless, I’ve missed something, Vegas lacks this degree of sophistication. It can certainly resize, but it does not produce the same level of quality.”

Ok, Vegas is far from ideal for upscaling photos. Photoshop is no great shakes, either. The best blowup you’re going to get is with specialized tools, though I’m fairly convinced that stair-interpolating in Photoshop does enlargements better than simply one-shot resizing. Surprisingly, Photoshop (as of CS4 anyway) doesn’t offer any of the more modern algorithms. You’ll get even better results on most material with windowed sinc (Lanczos 3) or spline resizing.. you can get sinc in The Gimp, InfranView, Virtualdub, AVISynth, etc. And there’s some argument for the various proprietary upscalers, such as reshade, BlowUp, or Perfect Resize (nee Genuine Fractals). But this is largely a print photograpy problem. If I have a small bitmap I need larger for video, I’m probably going to be unhappy with any upscaling alone. So I’m going to add blurring, art effects, something in my bag of tricks to hide the fact it’s a lousy image.

Vegas is only really designed to do down-scaling well. Which makes sense; you don’t usually upscale video, and when you do (eg, SD material into HD), you really want specialized processing. Vegas controls this with the “Full resolution rendering quality” setting in your project preferences. If you set “Good”, you get bilinear scaling, which is fast. If you set “Best”, you get bicubic scaling (“with integration”), not so fast, but better. And pretty similar to what Photoshop is going to give you. Sinc, spline, gaussian, etc. probably produce a better looking result, at the cost of time.

This is more applicable to Vegas anyway; Photoshop is NOT optimized for small image manipulation, it’s optimized for print work, lots of pixels. I have 750MB .PSD files around here. Vegas is pretty much only concerned with 8Mpixel and below (and usually, 2Mpixel and below), but also speed. The other thing about video; you don’t really have the time to spot small differences in resizing when displayed at 24-60fps. I assume that’s why Vegas has never bothered with a kernel more sophisticated than bicubic — you might see the difference, zoomed down in a photo editor. But on-screen? I’m personally not sure.

Of course, if you have the time, there’s the Content Aware resizing tool in Photoshop, which can be kind of magical… particular in dealing with aspect-ratio problems (there’s a plug-in for The Gimp that does similar things). It’s ok if you’re resizing a couple of photos, and it will produce a superior result. But for a large number in a complex video project, I’m probably not going there.

[Bob Peterson] “Certainly, if panning or zooming is needed, Vegas should have a larger image to accommodate that function, but routinely giving it 18 megapixel photos strikes me as a recipe of extremely long render times.
“

Certainly, for lots of static images, there’s no point in not resizing elsewhere just to make Vegas run faster. It depends quite a bit on how much you’re zooming/panning, and how much you’re using stills. If it’s all stills, I’ll bet the scaling time becomes significant enough (though still less work than, say, decoding AVC); if just a little here and there, I’m wasting time if I need a special step to resize in Photoshop.

Truth of the matter is, anything from my camera was shot in 18Mpixel RAW, and even though Vegas 11 supports RAW, that’s kind of joke, since they use Microsoft’s RAW decoder, which is like a decade out of date. So I’m almost certainly converting from RAW and/or 16-bit TIFF, selecting photos in Lightroom, which uses pretty much the same adaptive bicubic resizing algorithm that’s built-in on Photoshop.

-Dave

[Dave Haynie]

So.. this got me curious. Just what IS the impact of image size. Having 100’s of 18Mpixel shots around from a current photo project, I tried it. I created one 5min project with the 18Mpixel images, 5sec per image, and the same one with images resized by Lightroom to be 1080 pixels high. No crossfades, nothing but JPEG (since Lightroom doesn’t batch-convert PNGs) just image after image for 5 minutes. I render using Sony’s Blu-ray 1080/24p 16Mb/s preset. GPU rendering is on… I didn’t see enough GPU activity to worry about A/B-ing it.

Good/8-bit Best/8-bit Best/32-bit
Large 7:22 7:21 10:41
Small 7:10 7:06 10:37

So… yawn… not much of a win here in pre-resizing. There’s a difference, but it’s very insignificant compared to all the other work involved. There’s nothing shouting out quality-wise, either, though I didn’t do a photo-nerd-style examination of close up features. Maybe some other time.

So I did a slow zoom, so Vegas has to re-calculate every frame. In this, the large project has an 18Mpixel PNG, in the small project, that same image in PNG, resized to 4.5Mpixel. This is a zoom out for 1 minute. On the small project, the video starts at a zoomed-in height of 1080 pixels; on the large project, the start position is scaled deliver the same image size, but obviously with four times as many pixels.

Good/8-bit Best/8-bit Best/32-bit
Large 1:41 1:41 3:08
Large noGPU 1:54 1:59 3:12
Small 1:31 1:32 2:52
Small noGPU 1:43 1:49 3:04

Here I saw the GPU busy, so I decided to run both cases. This probably explains why “Good” and “Best” are tied — it’s all overhead, when you use the GPU for scaling. The actual math is fast enough to not be independently measurable. You could claim that the GPU case uses the same scaling algorithm in both cases, and while that’s possible, I have seen other cases in which “Good” vs. “Best” make a difference with the GPU.

Bottom line: if you’re concerned about highest quality, maybe you want to resize your images. If you’re on a low resource computer, also a good idea. But I think you have to go beyond Photoshop for any significant difference in quality, and for performance, you’re going to need a long and complex project before photo resizing makes a big difference.

I should point out a related issue I didn’t benchmark here: drive speed. If you have dozens of 18Mpixel images in the same project, you may kill your HDD performance and bottleneck there, not in the actual rendering pipeline. But this is more related to file size; 18Mpixel JPGs might well render faster than 2Mpixel PNGs, when you have very large numbers. And enough RAM.

I should point out that there has been some evolution here for sure. There was a time when Vegas had issues with larger photo files… and that was back in the 6-8Mpixel days of DSLRs. And Vegas 7.

-Dave