picture rotated when applying a transformation ?

[PicoJr]

Hello,

It appears that pictures are rotated during the transformation:

I haven't found out what is the cause for it yet ^^

But since it occurs for each transformation:

I guess it involves a function that is called regardless of the transformation.

Take care,

[PicoJr]

After further investigation:

Conversion to LMS seems to be the cause for the 1/4 rotation

• image arrays are matrices -> line i, column j, rgb k -> top right pixel is (0, width)
• PIllow images -> cartesian with origin top left -> top right pixel is (width, 0)

edit: the suggestion below only works for square ratio pictures.

editablePhoto[i,j,k] = photo[i,j][k] should be editablePhoto[i,j,k] = photo[j,i][k]

As for the symmetry, the normalization seems to be the cause.

I must admit I don't understand why a normalization is required ^^

Did you find the algorithm described somewhere?

Take care,

[tsarjak]

After further investigation:

Conversion to LMS seems to be the cause for the 1/4 rotation

• image arrays are matrices -> line i, column j, rgb k -> top right pixel is (0, width)
• PIllow images -> cartesian with origin top left -> top right pixel is (width, 0)

edit: the suggestion below only works for square ratio pictures.

editablePhoto[i,j,k] = photo[i,j][k] should be editablePhoto[i,j,k] = photo[j,i][k]

As for the symmetry, the normalization seems to be the cause.

I must admit I don't understand why a normalization is required ^^

Did you find the algorithm described somewhere?

Take care,

Yes, I have the link to the paper. Also checkout the updated version. It fixes all the issues.
https://arxiv.org/pdf/1711.10662.pdf