KNLMeansCL: OpenCL NLMeans de-noising algorithm [2018-01-29]

[WolframRhodium]

Originally Posted by anton_foy

Too bad, it is really fast and has so much better temporal stability compared to knlmeansCL.

The output of nlm-cuda should be closed to KNLMeansCL and should not result in an increase in image quality.

[anton_foy]

Originally Posted by WolframRhodium

The output of nlm-cuda should be closed to KNLMeansCL and should not result in an increase in image quality.

My mistake, yes they seem to give identical results yet only the first 4 frames seems to differ from eachother even when both using the same settings. But that doesn't bother me. Great plugin

@Tormento
Is the author here on Doom9 still? I cannot access his own forum.

[tormento]

Originally Posted by anton_foy

Is the author here on Doom9 still? I cannot access his own forum.

I think he is lurking but not officially here.

You can’t access or you can’t register?

In the second case, perhaps some users here and on his forum can ask him to create you an account.

He is very capable but also a bit weird.

[JamesJohnston]

I reported this issue on GitHub, but I'm not sure if anyone's monitoring that, so posting it here as well. More details in the GitHub issue: https://github.com/pinterf/KNLMeansCL/issues/6

In short, if the image width is a multiple of 64, KNLMeansCL outputs garbage - as seen in this test case:

plugin_dir = "C:\VideoProject\Software\AviSynth-plugin\"
LoadPlugin(plugin_dir + "KNLMeansCL.dll")

function test(int width) {
    input = ColorBars(width=width, height=480, pixel_type="YV24").Trim(0, 50).Subtitle(String(width), size=36).FadeOut(50).ConvertToY8()
    output = input.KNLMeansCL(ocl_x=8, ocl_y=16, ocl_r=1)
    StackVertical(input, output)
}

StackHorizontal( \
    test(8*1),  test(8*2),  test(8*3),  test(8*4),  test(8*5),  test(8*6),  test(8*7),  test(8*8),  \
    test(8*9),  test(8*10), test(8*11), test(8*12), test(8*13), test(8*14), test(8*15), test(8*16), \
    test(8*17), test(8*18), test(8*19), test(8*20), test(8*21), test(8*22), test(8*23), test(8*24), \
    test(8*25), test(8*26), test(8*27), test(8*28), test(8*29), test(8*30), test(8*31), test(8*32), \
    test(8*33), test(8*34), test(8*35), test(8*36), test(8*37), test(8*38), test(8*39), test(8*40), \
    test(8*41), test(8*42), test(8*43), test(8*44), test(8*45), test(8*46), test(8*47), test(8*48) \
)

I posted an example of an output frame in the GitHub issue. But what happens is the bottom row (filter output) is missing outputs (they are all black) whenever width is a multiple of 64.

In real-world videos, I've seen where the filter output gets stuck at a specific frame, and doesn't change when I move the AvsPmod slider bar to other frames. Other times, it will show partial or total garbage pixels, as if it was displaying uninitialized memory.

In practice, I'm trying to crop a standard definition 720x480 video down by a multiple of 16, which is coming out with a width of 704. That seems like it would be a fairly common scenario...? but that's a multiple of 64, so the rendered output comes out as garbage.