Color difference in 32 bit per channel input image to filter

Hi All

If I select the "RGB Color -  32 bit" color mode, there is a significant color difference between Photoshop preview and the input image to my filter as shown below.

The first image is snapshot of Photoshop preview. Second one is the input frame in my filter.

Note that, original image is 8 bits per channel and looks exactly like the first image. My code is similar to dissolve filter sample for accessing 32 bit image input.
Any idea about what could be going wrong?

Regards,

Chandan