DEPTH VALUE OF THE EACH PIXEL about midas HOT 12 OPEN

In order to get the true depth using the above method you need to know two true depth pixel values for each relative depth image you correct (realistically you want many more). This could come from a a sensor, sparse structure-from-motion point cloud, etc. if you don't have access to true depth and you need access to metric depth then you should look into Metric depth estimation methods like ZoeDepth, Depth-Anything,and ZeroDepth.

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According to #171 I believe the equation is:
(1.0 / true_depth) = A + (B * midas_output)
so then
true_depth = 1.0 / (A + (B * midas_output))

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The midas models output inverse depth maps (or images). So each pixel of the output corresponds to a value like: 1/depth

However, the mapping is also only relative, it doesn't tell you the exact (absolute) depth. Aside from noise/errors, the true depth value is shifted/scaled compared to the result you get from the midas output after inverting, so more like:

true depth = A + B * (1 / midas output)
(see post below)

Where A is some offset and B is some scaling factor, that generally aren't knowable using the midas models alone. You can try something like ZoeDepth to get actual depth values or otherwise try fitting the midas output to some other reference depth map, like in issue #171

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so then true_depth = 1.0 / (A + (B * midas_output))

Good point! I was thinking these are the same mathematically, but there is a difference, and having the shifting done before inverting makes more sense.

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How are A and B calculated for a video ? @JoshMSmith44

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How are A and B calculated for a video ? @JoshMSmith44

I believe MiDas is a single-image method and therefore there is a different A and B for each frame in the video sequence.

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How are A and B calculated for a video ? @JoshMSmith44

I believe MiDas is a single-image method and therefore there is a different A and B for each frame in the video sequence.

but in MIDAS it calculates using, true depth and calculated depth comparison. What if we have completely new images and want to find metric depth ?

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