an overlay marking the areas in the image where the image frequency is above a certain threshold, aka these are high contrast edges of "in-focus" elements.
Useful parameters:
- ON/OFF
- threshold
- color/transparency of the overlaid dots
- dot size
Example:
Description
Description
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Please define "image frequency" and explain how it is calculated from the raw Bayer data.
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Here is a great reference: http://www.luminous-landscape.com/forum/index.php?topic=56246.0
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thinking about it now it might also make sense to add "dot size" as parameter as most monitors with lower than FullHD resolution might not be able to display dots of 1 pixel size properly
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Just to sum up, the given algorithms are quite complex and require several rows (min 3) of data.
Is this usually applied to the processed image or the raw data?
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There might be ways to simplify/optimize the processing, after all we just need a rough helper indicator here not a scientific tool.
I guess it is usually applied to the processed image.
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Is it possible (and thus easier) to see this as extreme sharpening applied to the image? On the newer red cameras it looks more like sharpening, and it's very effective to do the focusing.
I guess working on more than previous and next pixels makes things harder or even impossible on the fpga level. Maybe the algo could work on a line basis?
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I find the 'sharpening' approach less helpful than the coloured edges. The former method often leads me feeling a little concerned, whereas the coloured edges leave you in no doubt.
I believe the focus peaking is applied to the processed image, although I can't think of any particular reason it couldn't be applied to the raw image.