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BradLarson / GPUImage

An open source iOS framework for GPU-based image and video processing
http://www.sunsetlakesoftware.com/2012/02/12/introducing-gpuimage-framework
BSD 3-Clause "New" or "Revised" License
20.25k stars 4.61k forks source link

how to get original screen coordinates of pixel when adapting histogram filter #2298

Closed kallipigous closed 8 years ago

kallipigous commented 8 years ago

I'm trying to adapt the histogram filter so that it create a video waveform. Essentially the x of the original pixel stays the same but the Y is dictated by the luminance of the pixel. The obvious place to start was the histogram filter but it looks like the pipeline no longer has the position data (the vertex shader position seems to have the rgb values instead and are used to calculate the luminance). In the histogram filter the x and y are dictated programatically and bear no relation to the original pixel position so presumably it's no longer needed.

Is there a way to get the screen coordinates to change only the Y but keep the original x position of the pixel.

Cheers

Toby

BradLarson commented 8 years ago

Given that we discussed this offline and came to a conclusion, I'll close out this particular issue.

kallipigous commented 8 years ago

Yes of course.

Many thanks.

.

On Jun 8, 2016, at 9:41 AM, Brad Larson notifications@github.com wrote:

Given that we discussed this offline and came to a conclusion, I'll close out this particular issue.

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub https://github.com/BradLarson/GPUImage/issues/2298#issuecomment-224650960, or mute the thread https://github.com/notifications/unsubscribe/AAlNgRDCMEczaEhlS5dKyt3pfCXlwUYNks5qJvC3gaJpZM4ItCMz.