Feature: Enhance head pose estimation

[saeidn95]

Changes to rotationMatrixToEulerAngle

Need for dropping the factor of 2 in return values (pitch, yaw and roll) in the function rotationMatrixToEulerAngle (

human/src/face/angles.ts

Line 56 in 1114014

const rotationMatrixToEulerAngle = (r: number[]): { pitch: number, yaw: number, roll: number } => {

)

The formulation can be modified as follows;
var cosThetaZ = math.sqrt(r00 * r00 + _r20 * _r20);
// thetaZ = Math.asin(r10);
thetaZ = Math.tan2(r10, cosThetaZ);

what this change thetaX, thetaY, thetaZ, are within the range of -pi to +pi, and there is no need to scale the return values by 2.

[vladmandic]

why not submit a PR?

[saeidn95]

I could not quite figure how to do that. Let me try again.

[vladmandic]

it would be better as then your name goes to contributors list. if you can't, I'll deal with it next week.

[saeidn95]

Not sure if I did it right, but I did a pull request now.

[vladmandic]

sorry for a long delay, somehow this dropped off the radar.
anyhow, you did a pull request on your fork of this repo, you never submitted it to actual upstream (this) repo.
go to main...saeidn95:human:main and you can click create pr there.

but...your code is non-functional as it is:

var cosThetaZ = math.sqrt(r00 * r00 + _r20 * _r20);

there is no math, it should be Math and there are no _r20 values, so which ones you wanted to use?
i can test on my side and do the changes if you don't want to deal with pull request, but at give me a working code :)

[saeidn95]

Apologies for typos. Please replace _r20 with r20), The equation should be
var cosThetaZ = math.sqrt(r00 * r00 + r20 * r20);

You can double check that by looking at the formulation that you use in section 2.4 in reference https://www.geometrictools.com/Documentation/EulerAngles.pdf

Please go ahead and do the changes yourself. I would appreciate that. That saves doing a pull request on a code that is wong anyway!

BTW: is there a reason you use _r01, and _r02 instead of r01, and r02 in

human/src/face/angles.ts

Line 56 in 1114014

const rotationMatrixToEulerAngle = (r: number[]): { pitch: number, yaw: number, roll: number } => {

[vladmandic]

BTW: is there a reason you use _r01, and _r02 instead of r01, and r02 in

underscore in front of variable visually indicates that variable is not actually used in the code.

Please go ahead and do the changes yourself. I would appreciate that

done, will be pushed to github soon.