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.

SK-AM62A-LP: Want to use ISP autofocus functionality with AM62A34

Part Number: SK-AM62A-LP

Hello Team,

We want to use autofocus functionality  on AM62A34. As per Technical reference Manual it is mentioned that chip is supporting autofocus feature on ISP.

Please let me know how can I use this auto focus functionality from ISP to read statics information.

Thanks,

  • Hi Jaimin,

    We have not documented the auto focus feature. Could you please share little more details on your use-case so that we can get try and put something together.

    Thanks

    Yogesh

  • Hi Jaimin,

    As per Technical reference Manual it is mentioned that chip is supporting autofocus feature on ISP.

    To be clear, ISP (VPAC-VISS) only supports collecting some statistics for AF in VPAC-VISS-H3A.

    You may refer to the VPAC-VISS-H3A-AF section in TRM for more details.

  • We have not documented the auto focus feature. Could you please share little more details on your use-case so that we can get try and put something together.

    We are planning to use DRV201YMBR VCM drive autofocus chip from TI which receives lens movement information through I2C from AM62A34 processor. Now on AM62A34 we want to get statistic from ISP's autofocus engine and based on it we want to drive external DRV201YMBR. Now below are our questions.

    1. How we can get statistics data from ISP's autofocus engine?
    2. What data provided in statistics and how we can interpret it for lens movement?
    3. We are using monochrom sensor so considering we will get some image sharpness specific information from autofocus engine and that data we will use to drive for VCM lens movement. Is this correct understanding?

  • Hi Jaimin,

    1. How we can get statistics data from ISP's autofocus engine?

    VISS-H3A will output the statistics to DDR.
    One limitation on AM62A/TDA4 is that VISS-H3A can only output either AF statistics or AEWB statistics for any input raw image frame (not both).

    2. What data provided in statistics and how we can interpret it for lens movement?

    Please refer to AM62A TRM for VISS-H3A-AF details.

    3. We are using monochrom sensor so considering we will get some image sharpness specific information from autofocus engine and that data we will use to drive for VCM lens movement. Is this correct understanding?

    Yes, roughly speaking, H3A-AF measures how sharp the input image is.
    H3A-AF assumes input image is raw 2x2, e.g., Bayer pattern.

  • VISS-H3A will output the statistics to DDR.
    One limitation on AM62A/TDA4 is that VISS-H3A can only output either AF statistics or AEWB statistics for any input raw image frame (not both).

    Is there BSP support available to read this data. I have EVM for AM62A34 and IMX219 sensor. Could you please point me to document how can I read this statistics data?

    Yes, roughly speaking, H3A-AF measures how sharp the input image is.
    H3A-AF assumes input image is raw 2x2, e.g., Bayer pattern.

    We are planning to you auto focus with monochrome image sensor let me know if there is any concern with that.

  • Hi Yogesh,

    It would be really helpful if you can provide some reference to read autofocus statistics on AM62A34 EVM. 

    Thanks

  • Is there BSP support available to read this data. I have EVM for AM62A34 and IMX219 sensor. Could you please point me to document how can I read this statistics data?

    You may refer to TRM VISS-H3A section for AF output data package format details.
    I am not sure about the s/w support on AM62A.

    We are planning to you auto focus with monochrome image sensor let me know if there is any concern with that.

    This also depends on if you would need to use VPAC-VISS to process your monochrome sensor image.
    If not, it may not worth running sensor raw images through VISS just for H3A-AF statistics because of DDR bandwidth and latency.
    You may use the ARM core to look at the mono sensor image and do AF directly on Linux side.

    H3A-AF is not designed for monochrome images.
    You may still use it as if the input is a Bayer pattern, but it will less accurate for sure.

  • This also depends on if you would need to use VPAC-VISS to process your monochrome sensor image.
    If not, it may not worth running sensor raw images through VISS just for H3A-AF statistics because of DDR bandwidth and latency.
    You may use the ARM core to look at the mono sensor image and do AF directly on Linux side.

    Hi Gang

    Any information available how we can perform auto focus with help of ARM core?

    As per my understanding, There should be some algorithm which we can run on ARM and it will provide image statistics. Any reference available for this?

    H3A-AF is not designed for monochrome images.
    You may still use it as if the input is a Bayer pattern, but it will less accurate for sure.

    Is there any information available what is the accuracy with monochrome sensor? Can we do any work around to get proper statistics data with monochrome image sensor with ISP H3A Auto Focus?

    Thanks

  • Hi Jaimin,

    Any information available how we can perform auto focus with help of ARM core?

    Unfortunately, we don't have any reference or past experience about AF at TI.
    It has been done by customers or 3rd parties on their own.

    Is there any information available what is the accuracy with monochrome sensor? Can we do any work around to get proper statistics data with monochrome image sensor with ISP H3A Auto Focus?

    VISS and H3A can take monochrome images as if they are Bayer pattern images.
    You may take a look at the TRM to understand how H3A-AF works.
    It requires you to configure the filters in H3A-AF to generate the AF-statistics.