Why the captured frame using ADV7182 is not sharp and are black areas around low intensity observed?

Hi All,

We are capturing from CVBS camera with single ended configuration using ADV7182. Frames are captured properly on the processor with de-interlacing .But the captured frames are not sharp and we can see black colored pixels on the low lit(intensity) areas.

We did not doubt on the processor software as the same code was running good with Intersil TW9966. How can we make the frame sharper without any dark spots.

With regards,

Jeyaseelan 

P.S. Have attached the captured frame for referance. Please see on the eye,chin areas of the person in the frame.these areas are black colored and overall the frame quality is not good.

Parents
  • DV718X_Config_T adv718x_config[] =
    {
    /*Exit Power Down Mode*/
    {0x0F,0x00},
    /*INPUT CONFIGURATION*/
    {0x00,0x0e},
    /*Set INSEL Register1*/
    {0x0E,0x80},/*ADI Required Write; Reset Clamp Circuitry (step1)*/
    {0x9C,0x00},/*ADI Required Write; Reset Clamp Circuitry (step2)*/
    {0x9C,0xFF},/*ADI Required Write; Reset Clamp Circuitry (step3)*/
    {0x0E,0x00},/*ADI Required Write; Reset Clamp Circuitry (step4)*/
    /*ENABLE DIGITAL OUTPUT CIRCUITRY*/
    {0x03,0x0C},/*Enable Pixel & Sync output drivers*/
    {0x04,0x07},/*Power-up INTRQ, HS and VS/FIELD/SFL pad*/
    {0x13,0x00},/*Enable INTRQ output driver*/
    {0x1D,0x40},/*Enable LLC Output Driver*/
    /*SELECT CHROMA SHAPING FILTER MODE*/
    {0x17,0x41},/*Select SH1 Chroma Shaping Filter*/


    {0x31,0x12},
    {0xe6,0x44},
    {0x52,0xC0},/*Set optimized IBIAS for the AFE (see the \u2018Set Analog Front End IBIAS Settings\u2019 section)*/
    {0x5f,0xa8},
    {0x5a,0x90},
    {0x60,0xB0},
    {0x0e,0x80},
    {0xb6,0x08},
    {0xc0,0xa0},
    {0x0e,0x00},
    #if 0
    /*FAST SWITCH MODE*/
    {0x0e,0x80},
    {0xd9,0x44},
    {0x0e,0x40},
    {0xe0,0x01},
    {0x0e,0x00},
    #endif
    /*ADAPTIVE CONTRAST ENHANCEMENT*/
    {0x0E,0x40},/*Enter User Sub Map 2*/
    {0x80,0x80},/*Enable ACE Feature*/
    {0x04,0xB5},/*ITU-BT656.4*/
    {0x84,0x00},
    {0x0E,0x00},/*Re-enter User Sub Map*/
    };

    Above is the i2c configuaration used

    Thanks

  • 0
    •  Analog Employees 
    on Sep 27, 2018 1:18 PM over 2 years ago in reply to Jeya

    Hi,

     In Luma/Chroma shaping filter, when automatic mode, the system preserves the maximum possible bandwidth for good CVBS sources (because they can be successfully combed) as well as for luma components of YPrPb and Y/C sources (because they need not be combed). For poor quality signals, the system selects from a set of proprietary shaping filter responses that complements comb filter operation to reduce visual artifacts.

    And also refer Page40 for adjustment of ACE.

    Thanks,

    Poornima

  • Hi Poornima,

    We have set both the Luma/Chroma shaping filter to automatic and also enabled ACE.Still the image is not sharp .

    Following are the registers used for this 

    Reg 0x17 is set  to values 0x41 , 0xE1 etc.

    Also ACE also enabled .

    {0x0E,0x40},/*Enter User Sub Map 2*/
    {0x80,0x80},/*Enable ACE Feature*/
    {0x83,0x1F},/**/
    {0x84,0xFF},/**/
    {0x85,0xFF},/**/
    {0x0E,0x00}/*Re-enter User Sub Map*/

    Have attached the comparision image between TW9966 and ADV7182 ,on which image of TW9966 is sharper .

    Please let me know if any other changes to be done for enhancing the quality .

    With regards,

    Jeyaseelan

  • Hi ,

    I have another problem also where the first few vertical lines are black and also the horizontal lines start with few pixels of offset. How can i avoid such black colors to start the frame start exactly start from origin(x-0,y-0). Thanks.

    With regards,

    Jeyaseelan

  • 0
    •  Analog Employees 
    on Oct 4, 2018 1:29 PM over 2 years ago in reply to Jeya

    Hi,

    Try to adjust the color control register bit, this change may be reflect to the quality of the picture .
    The second thing I'd look at is Digital Noise Reduction (DNR) settings on page 41 of the manual and
    Note the ADV7180 does have 10MHz anti-aliasing filters (AAF) that remove EMI above the CVBS video frequency band.
    Please refer https://ez.analog.com/video/w/documents/614/adv7183b-video-noise-on-the-output

    Thanks,

    Poornima
     

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