Turn off quantization?

[jbrownkramer]

Is it possible to turn off quantization? We'd prefer not to take the data loss.

[catid]

Yeah feel free to make any edits you like

[dotproduct3d]

@catid How is Zdepth a lossless format when there is quantization?

[catid]

@catid How is Zdepth a lossless format when there is quantization?

It is because the sensor itself is inaccurate, so we are basically just chopping off the noise

[PiotrGizaB3D]

@jbrownkramer @dotproduct3d Thank you guys for opening this topic. I tried to compress custom 3D data (not from Kinect) using zdepth. The algorithm reached astonishing compression ratio value of ~0.11. But all data verification tests failed: vectors were just different after performing compression/decompression. Then I tried to disable quantization. It seemed that the "12bit-packing" must be disabled as well (otherwise values higher than 4095 could be saturated). Compression ratio was still good (about ~0.25). All tests in zdpeth_test were successful. But when I tried to compress my own data, I only got "Corrupted" errors. I dived into the code and discovered that in DecompressImage() method there is a cast from int returned by UndoPrediction() to an uint16_t. In some cases this cast cannot be valid since the result of UndoPrediction() may be negative (hence the problems).

I do not say that it is impossible to use zdepth with custom data from devices other than Kinect, but it will surely be a very complex task.