• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 99 subscribers
  • Views 649 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DM6446 preview engine RGB blend tuning.

Manjur13397
Prodigy 60 points

Hi folks,

I have an issue on dm6446 preview engine which is that the color of video image is not little bit greenish. 

At the beginning it was yellowish video. Then I have changed the RGB2RGB blending matrix and got little bit better image. But it turns to greenish image.

It would be great if someone give me direction how to tune the preview engine of dm6446 with my Aptina MT9V034 camera so that I can get good color.

The camera capture path is

CCDC ----> DDR (raw image)----> preview -----> DDR (yuv422 iamge)

 

 

  • 0
    TI__Mastermind 37340 points

    As you may know, DM6446 treats RAW input into preview engine as Bayer Pattern data (detailed on VPFE User Guide); therefore, you need to make sure that this is what the Aptina sensor is feeding to DM6446.  If sensor was feeding RGB data instead of Bayer Pattern data. this would explain the behavior you are seeing. 

    If you are indeed feeding Bayer Pattern data into preview engine and not seeing the correct color out, then we would need to investigate a little further... where did you get the driver to exercise your sensor?  I believe Leopard imaging provides a Aptina sensor (not the same one) based daughter card that sits on top of our DM6446 EVM; they also provide the software for their daghter card.  Even though it is not the same sensor as yours, it can offer insight into how the DM6446 portion needs to be programmed by the driver.

  • 0 in reply to Juan Gonzales
    Prodigy 60 points

    Thanks Juan for your reply. The camera I am using gives Bayer Pattern data. I have collected driver from ti-davinci mvl4.0.1.  The output from my camera is good regardless the actual color. I dont know how to tune the preview engine with rgb2rbg blending matrix, white balance/dark frame. I believe preview engine parameter should be tuned with different type of cameras. I have changed the rgb2rgb matrix value and got better color though it is not so perfect.

    Here is a screenshot of my camera attached here. The white color is not real white as well as other colors from my colorchecker chart.I had to do all possible combination of rgb blending matrix and checked the image(looking at the screen hours for hours) to find this current color. But this process is time consuming.

    Is there any systematic procedure to measure the preview engine parameter?

  • 0 in reply to Juan Gonzales
    Prodigy 150 points

    HI,
       I am using DM6446 and debugging Video process sub system.

       CCD module of VPFE (video processing front end ) gets video data from adv7189 decoder.
     
       I want to know if the data that has been processed  by VPFE must be stored   into  external SDRAM.
      
       Can I store/read directly some data that has been processed by VPFE  into on-chip RAM of DM6446 ??
     
       How ??

       Thanks!!

  • 0 in reply to wang shu
    TI__Mastermind 37340 points

    wang shu said:

       
       Can I store/read directly some data that has been processed by VPFE  into on-chip RAM of DM6446 ??
     
       How ??

    Unfortunately, I do not believe this is possible.  VPSS either sends video data to the next stage in the VPSS pipeline or uses buil-in DMA to send data to DDR2.  User application can access data from DDR2.