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Is my capture raw image right?(VPFE Tuning using ITT)

wq p
Prodigy 180 points

I use the DM368 + Image Tuning Tool to tune the image color.But when I captured the *.rawTI image data, i doubt it was not right, because the image looks very dark and the brightness was not  the same as  show in  video.

I think the image that I captured and the video i saw are under different processing. I read the VPFE datasheet,and I think if I turn off the RGB2RGB blender, and bypass the White balance , and bypass the Gamma, the raw data and video should be in the same brightness.

In Image Tuning Tool, I read back the parameter,and set the diagonal value of RGB2RGB to 256 and others 0, and the same as RGB2RGB2 ,and bypass the Gamma ,and white balance I set to 512 (it should be 1.0x). Although I tried this ,but the video image is still brighter to the raw data image(I have turned AEWB off).

can anyone tell me what is getting wrong ?

Any input is appreciate much!

  • 0
    TI__Guru 58830 points

    There is not anything wrong.

    Raw images (rawTI files) are supposed to be dark, since no gamma correction is applied.

    If you capture the yuvTI files, you will get images very close to your video.

  • 0 in reply to Gang Hua
    Prodigy 180 points

    Hi, Gang Hua !

         Thank you very much for caring my problem!

         I know that there are two data paths when processing the image data. And one path is the image data written into DDR2, and then the image data are captured.  Another path is that to Encoder, and the image data become video after H.264 encoding.  

         But I think , if two  data path have the same Gain , the raw data and the video are supposed to be the same brightness . So in IPIPE, I bypass the Gamma, bypass the  RGB2RGB ,RGB2RGB2, and the white balance. But the really video is still brighter than the raw data. Is still any gain applied to the video data ?

        Regards,

        WqPang.

  • 0 in reply to wq p
    TI__Mastermind 22145 points

    Hi WqPang,

    This could be because of the right shift done on the RAW image saved to DDR. Can you check the CCDW value in "ISIF_MODESET". I am guessing that the RAW data stored is 10 bit.

    Regards,

    Kumar

  • 0 in reply to wq p
    TI__Guru 58830 points

    You are thinking along the right path.

    However, there is no way to "really" bypass Gamma and there is no standard way to comparing 12-bit raw against 8-bit yuv for brightness.

    Plus, there is no way to display 12-bit raw images directly on a normal PC display.

    Please do this as a simple exercise: if the input raw image is 512 for every pixel, what is the output yuv image when you bypass everything?

    Once you have those numbers, do you think it is brighter or darker than the original raw image?