[ADV728xA-M] Any method or register settings to improve image quality after I2P conversion.

Hello.
 
I have a question about I2P conversion in ADV7282A-M.

Question:
 Is there any method or register settings to improve image quality for I2P (interlace to progressive) conversion?

I saw a following thread related to the I2P algorithm:
https://ez.analog.com/video/f/discussions/5630/deinterlacer-i2p-algorithm-of-adv728x-devices/24765#24765

In this thread, the expert said that
"Vpp Map register 0x5A bits [4:3] control the I2P mode of the ADV728x.
 By default these bits are 0b'11. This produces the ADI propritery deinterlacer algorithm. I strongly advice useing this mode for all applications. "

So I think there are registers related to I2P mode (0x5A[4:3]). However, I assume that the default setting is most appropriate to image quality.
If you have any method or register settings to improve image quality which is converted I2P, could you tell me it?
Even if you don't have it, please let me know.

Thank you!
Best regards.
Tamu

Parents
  • 0
    •  Analog Employees 
    on Nov 6, 2020 6:18 PM 3 months ago

    Hi,

     As per expert comment "I2P does not contain smoothing filter. But by Modifying some of the registers in the ADV728x we can see some improvement in the image.
         Please try reading the Chroma filter, Luma Filter, Chroma Transient Improvement, Digital Noise Reduction and Luma  Peaking Filter, and Comb filter sections of the ADV728x hardware manual. You may get some improvement .

    Please note that If it is custom board,Please refer application note for layout design www.analog.com/.../AN-1337.pdf
    Note : Ensure the proper clock rate(27Mhz) has given.

               All filtering and termination is performed in the D-PHY layer of the ADV7280-M,
    ADV7281-M, ADV7281-MA, and ADV7282-M transmitter devices and in the D-PHY layer
    of the MIPI CSI-2 receiver. Do not place additional components, such as resistors,
    electrostatic discharge (ESD) diodes, capacitors, or common-mode chokes on the MIPI CSI-2 traces
     And also the feedback loop between the current clamps and the video processor fine-tunes this coarse dc offset and makes the clamping robust to noise on the video input.So the current clamps are controlled within a feedback loop between the AFE and the video processor; the coarse clamps are not.

    Thanks,

    Poornima

Reply
  • 0
    •  Analog Employees 
    on Nov 6, 2020 6:18 PM 3 months ago

    Hi,

     As per expert comment "I2P does not contain smoothing filter. But by Modifying some of the registers in the ADV728x we can see some improvement in the image.
         Please try reading the Chroma filter, Luma Filter, Chroma Transient Improvement, Digital Noise Reduction and Luma  Peaking Filter, and Comb filter sections of the ADV728x hardware manual. You may get some improvement .

    Please note that If it is custom board,Please refer application note for layout design www.analog.com/.../AN-1337.pdf
    Note : Ensure the proper clock rate(27Mhz) has given.

               All filtering and termination is performed in the D-PHY layer of the ADV7280-M,
    ADV7281-M, ADV7281-MA, and ADV7282-M transmitter devices and in the D-PHY layer
    of the MIPI CSI-2 receiver. Do not place additional components, such as resistors,
    electrostatic discharge (ESD) diodes, capacitors, or common-mode chokes on the MIPI CSI-2 traces
     And also the feedback loop between the current clamps and the video processor fine-tunes this coarse dc offset and makes the clamping robust to noise on the video input.So the current clamps are controlled within a feedback loop between the AFE and the video processor; the coarse clamps are not.

    Thanks,

    Poornima

Children
  • Hi,

    Thank you for your reply!

    About your comment,
    "I2P does not contain smoothing filter. But by Modifying some of the registers in the ADV728x we can see some improvement in the image.
     Please try reading the Chroma filter, Luma Filter, Chroma Transient Improvement, Digital Noise Reduction and Luma  Peaking Filter,
     and Comb filter sections of the ADV728x hardware manual. You may get some improvement ."

    If you have any example or reference information how / which register should be changed for the improvement, could you tell me it?
    The filter registers you indicated are too much. So the customer wants the example / reference information how the registers should be changed for the improvement.
    It really helps the customer

    Thank you!
    Best regards.
    Tamu

  • +1
    •  Analog Employees 
    on Nov 10, 2020 10:41 AM 3 months ago in reply to Tamu

    Hi,

      Below i have provided these register information and these information will also be available in hardware manuals,

        1.Digital noise reduction (DNR ) is based on the assumption that high frequency signals with low amplitude are probably noise and that their removal, therefore, improves picture quality, But by default this block will be enabled, So please make sure with the register 0x4D.

      2. ADV728x contains a chroma transient improvement (CTI) processor that sharpens the edge rate of chroma transitions, resulting in sharper vertical transitions. However, it operates only on edges above a certain threshold to ensure that noise is not emphasized. . But by default this block will also be enabled. Also Please make sure with these related registers like CTI_AB_EN, CTI_AB in register 0x4D.

      3. Luma and chroma related configuration is available in register 0x17, in reference script we have configured this 0x17 register as 41. Please refer figure25(YSFM and WYSFM Control Flowchart) and change the Y/C filter configuration according to your need.

    Generally luma and chroma filters are used to set the bandwidth of the luma and chroma. 2D comb filters are used for Y-C separation.

    Thanks,

    Poornima

  • Hi,

    Thank you for your reply.
    I told your information to the customer and they have been trying them to improve the image quality.
    If they have some additional questions, please let me ask them.
    If they have no additional questions, I'll close this question.

    Thank you!
    Best regards.
    Tamu

  • 0
    •  Analog Employees 
    on Nov 16, 2020 5:22 AM 3 months ago in reply to Tamu

    Hi,

     Thank You.

    Regards,

    Poornima