XnConvert B/W Tiff to JP2 Converted file is not opened in Photoshop

[Raja2401]

I have converted some Black and white Tiff files to JP2 format using XnConvert and found following issues with JP2 output files, kindly clarify/Advise.

1) Input B/W Tiff - Expected result: B/W JP2
Why Converted JP2 output is in Grayscale mode and not retaining the original B/W mode?

2) Why Converted JP2 output is not opened in Photoshop?

Thanks in advance.

[cday]

I have converted some Black and white Tiff files to JP2 format using XnConvert and found following issues with the JP2 output files:

1) Input B/W Tiff - Expected result: B/W JP2
Why is the converted JP2 output in Grayscale mode and not retaining the original B/W mode?

If the output image has 8-bit depth, I suspect that JP2 does not support 1-bit output: JPEG2000 according to Wikipedia is related to the JPEG format which only outputs to colour and grayscale.

I presume that the output image displays as nominally black and white, but in the file info the number of colours may be greater than two.

2) Why Converted JP2 output is not opened in Photoshop?

If possible and it is still relevant, could you upload an example file for Pierre to examine?

Edit:

Do you particularly need to convert to JPEG2000, if you need is to reduce file size then there are better options.