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Test Class 2: Noise And Artifact Reduction

Video Quality Tested: GeForce Vs. Radeon In HQV 2.0
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This class is all about improving poor-quality, noisy video. Today’s video processors can remove unwanted noise from video without noticeably blurring or degrading the picture.

Chapter 1: Random Noise Tests

Random noise is the grainy, changing pattern you might notice on poor-quality video. This chapter contains four tests, comprising four different video clips that present unique challenges for random noise removal. A perfect score of five is given for each scene if noise is reduced, but details are intact. The score is lowered to two if noise isn’t significantly reduced, and a score of zero is given if noise isn’t reduced or the details have been softened and smeared.

This test is fairly simple to assess, even if there is an element of subjectivity here. All of the graphics cards we’re testing achieve a perfect score, although we note that the Radeon noise reduction appears superior. GeForce noise reduction isn’t quite as strong when it comes to moving objects, no matter what level the de-noise option is set to.

Random Noise Test Results (out of 5)

Radeon HD 6850Radeon HD 5750Radeon HD 5670Radeon HD 5550Radeon HD 5450
Sailboat5
5
5
5
5
Flower
5
5
5
5
5
Sunrise
5
5
5
5
5
Harbor Night
5
5
5
5
5

GeForce GTX 470GeForce GTX 460GeForce 9800 GTGeForce GT 240GeForce GT 430GeForce 210
Sailboat55
5
5
5
5
Flower5
5
5
5
5
5
Sunrise5
5
5
5
5
5
Harbor Night5
5
5
5
5
5


Chapter 2: Compression Artifacts Tests

Compression artifacts are very different from the grainy patterns in random noise. Compression noise usually manifests as blocky edges on objects or even squared-off areas of the video that contain nothing. This chapter has four test videos that suffer from compression artifacts: a moving text pattern, a roller coaster scene, a Ferris wheel scene, and a large bridge scene with a lot of slowly moving traffic.

To achieve a full score of five in each scene, compression artifacts must be significantly reduced, while the details remain crisp. A reduced score of three is given if the artifacts are substantially but “not fully” reduced, and zero is earned if the artifacts are not lessened or the scene is smeared and detail is softened.

We find the compression artifacts test (and the upscaled compression artifacts test coming up) to be the most difficult tests to judge. The first problem is that the guidelines are quite subjective: five points for “significantly reduced” versus three points for “reduced, but not fully.” The other issue is that while certain cards are able to reduce some compression artifacts, the result isn’t dramatic. The changes are subtle at best.

Compression Artifacts Test Results (out of 5)

Radeon HD 6850Radeon HD 5750Radeon HD 5670Radeon HD 5550Radeon HD 5450
Scrolling Text
5
5
3
3
3
Roller Coaster
5
5
3
3
3
Ferris Wheel
5
5
3
3
3
Bridge Traffic
5
5
3
3
3

GeForce GTX 470GeForce GTX 460GeForce 9800 GTGeForce GT 240GeForce GT 430GeForce 210
Scrolling Text0
0
0
0
0
0
Roller Coaster0
0
0
0
0
0
Ferris Wheel0
0
0
0
0
0
Bridge Traffic0
0
0
0
0
0


Let’s start with the Radeons. It appears that a relatively high de-noise value helps reduce compression artifacts, something that allows even the low-end Radeons to achieve decent scores here. Surprisingly, the de-blocking option doesn’t seem to make much difference, though. Once we reach the Radeon HD 5750, the GPU is powerful enough to enable mosquito noise reduction, and this does appear to have a positive (but relatively subtle) effect on compression artifacts. We do judge that this effect is enough to earn a score of five, however, and this sets the bar for the consumer graphics cards that we’ve tested.

The GeForce cards don’t have a dedicated option to reduce compression artifacts, such as mosquito noise reduction or de-blocking, and the noise reduction setting in the Nvidia driver doesn’t appear to affect anything but grainy noise. Because we can’t see any difference with noise reduction on or off, we’re forced to give the GeForce cards a zero score in this test.

Chapter 3: Upscaled Compression Artifacts Tests

The tests here are identical to the ones we looked at in Chapter 2, the only difference being that the video is now upscaled from a lower resolution. This results in more dramatic compression artifacts and looks more like something you might see from a low-resolution source—think YouTube video.

The GeForce cards still have a hard time with compression artifacts, and the Radeons struggle as well here. As a result, AMD's cards do not achieve the high scores across the board that they did in the previous test.

Upscaled Compression Artifacts Test Results (out of 5)

Radeon HD 6850Radeon HD 5750Radeon HD 5670Radeon HD 5550Radeon HD 5450
Scrolling Text
3
3
3
3
3
Roller Coaster
5
5
3
3
3
Ferris Wheel
3
3
3
3
3
Bridge Traffic
3
3
3
3
3

GeForce GTX 470GeForce GTX 460GeForce 9800 GTGeForce GT 240GeForce GT 430GeForce 210
Scrolling Text0
0
0
0
0
0
Roller Coaster0
0
0
0
0
0
Ferris Wheel0
0
0
0
0
0
Bridge Traffic0
0
0
0
0
0
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