Why does some values of a disparity map exceed 95?

yoon

I know that the range of disparity search is limited by 95.

But when I analyze disparity maps from Steredepth node, there are points that exceed 95.

I am using subpixel mode with 3 fractional bits and I know this feature make disparity level expand 8 times further.

Should I devide disparity value by 2^{fractional bit}?

erik

Hi yoon ,
Why would you divide the disparity values? For visialuzation purposes, you can use:

disparityMultiplier = 255 / stereo.initialConfig.getMaxDisparity()
# ...
dispFrame = inDepth.getFrame()
dispFrameColor = (dispFrame * disparityMultiplier).astype(np.uint8)

Thoughts?
Thanks, Erik

yoon

Just I would like to know actual disparity.

If I use fractuinal bits 3 and disparity value is 240, actual disparity will be 30. Am I right?

jakaskerl

Hi yoon
Yes, I believe so. You just need to use the formula for total subpixel disparity steps:
94 depth steps * 8 subpixel depth steps + 2 (min/max values) = 754 depth steps

Alternatively, you could cross-check with normal disparity to see if the values match you expectations/calculations.

Hope this helps,
Jaka

yoon

jakaskerl Thank you so much. Sorry for late reply.