Why is brightness changing when using the Malvar algorithm?

[song4me]

Hi,
When using the Malvar algorithm I get an output image which is much brighter than the original input image.
This change is different for different images. What is the reason this happens?

[KelSolaar]

Hi @song4me,

How are you reading the image? Is it a linear floating-point image in [0, 1] range?

Cheers,

Thomas

[song4me]

Hi Thomas,
Thanks for your quick reply.
I read the image using colour.io.read_image and indeed got a linear floating-point image in the range of [0, 1].
I disabled the eotf_inverse_sRGB function (which was causing some of the brightness change and is not needed for me), but there's still a slight change in colors which I can't trace.

The code I'm using is the one below

IMAGE = colour.io.read_image('in.bmp')
im_out = colour_demosaicing.demosaicing_CFA_Bayer_Malvar2004(IMAGE, pattern='RGGB')
colour.io.write_image(im_out, 'out.bmp')

Thanks,
Shirley

[KelSolaar]

Hello,

Would you have an example and/or the source image?

Cheers,

Thokas

[song4me]

Hi,
I'm attaching the input :

Result with opencv (for color comparison)

Results with Malvar from the colour demosaicing lib:

thanks