TDA2EG: SRV Photometric alignment adjustment Issue

xuanbo

Part Number: TDA2EG

I am working on the 2D SRV, and got a display result as follows:

as you see, the geometric alignment is OK, but the photometric alignment is not good. There is a obvious difference on color and brightness between two adjacent views.

So my question is how to improve this? And are there any ways to set the 4 views's color, brightness and white balance to the same value? Then the whole view will look like as if it were

taken by a single camera.

Thanks

xuanbo

over 7 years ago

0 Suryamani Jena over 7 years ago

TI__Expert 3720 points

Hi xuanbo,

Could you please share setup details ?

which cameras ?

which deserializer board ?

& did you calibrated before running SRV UC or it it with default calibration ?

Regrads

Suryamani Jena

0 xuanbo over 7 years ago in reply to Suryamani Jena

Expert 1550 points

Hi Suryamani

I used our own custom board based on TDA2Ex, with CSI2 camera interface. (usecase: rtos\usecases\csi2_cal_sv_standalone)
Yes, i have done the calibration. As you see the image in my post, the geometric alignment is good which means the calibration is successful.
But i think the calibration can only solve the problem of geometric alignment. Now my issue is photometric alignment with obvious difference on color and brightness. (This problem is more serious when i tested it outdoor)

Thanks
xuanbo

0 Sujith over 7 years ago in reply to xuanbo

TI__Genius 12455 points

Hi Xuanbo,

Can you please help me with following
1. Which camera / sensor are you using
2. Does this camera support Auto Exposure (AE) & Auto White Balance (AWB)

If the camera supports these features, please check if these enabled.

From your statement "This problem is more serious when i tested it outdoor" i suspect that AEWB is not enabled in the camera.

Regards,
Sujith

0 xuanbo over 7 years ago in reply to Sujith

Expert 1550 points

Hi Sujith

My camera sensor is OV10635, and it support Auto Exposure (AE) & Auto White Balance (AWB).

So how to enable these features? by I2C?

Thanks

xuanbo

0 xuanbo over 7 years ago in reply to xuanbo

Expert 1550 points

This is the test result at outdoor:

0 Luke Lin over 7 years ago in reply to xuanbo

TI__Expert 3250 points

Hi, Xuanbo

First you need to get OV10635 datasheet from OV. Find the registers used to control AWB and AE then modify the corresponding reg value in the driver.

For example,

AWB is controlled mainly thru below registers.

Address: 0x5000
Default: 0xFF
Read/Write: RW
   Bit[2]: AWB statistics enable
     0: Disable
     1: Enable
   Bit[1]: AWB gain enable
     0: Disable
     1: Enable

Address: 0x5120
Name: ISP_CTRL01
Default: 0x00
Read/Write: RW
   Bit[0]: White balance (WB) mode select
      0: Auto mode
      1: Manual mode

Address: 0xC4B8
Name: CT_AWB_EN
Default: -–
Read/Write: RW

   Bit[0]: Select AWB algorithms
      0: Select simple WB
      1: Select advanced WB

AEC is enabled/disabled thru below register

Name: ISP RW01 0xBF RW
Address: 0x5001
Default: 0xBF
Read/Write: RW
   Bit[7]: Data and its weight synchronization enable
   Bit[6]: Black/white mode enable
   Bit[5]: Dark level filter enable
   Bit[4]: Buffer control enable
   Bit[3]: AEC enable
   Bit[2]: Tone mapping enable
   Bit[1]: Normalize enable
   Bit[0]: Long-short combination enable

For TI-RTOS Vision SDK, the reg value is set in the following file.

\ti_components\drivers\pdk_01_09_00_17\packages\ti\drv\vps\src\devices\ov1063x\src\bspdrv_ov10x3xReg.c

{0x5000, 0xff, 0x0},

{0x5120, 0x0, 0x0},

{0xc4b8, 0x0, 0x0},

{0x5001, 0xbf, 0x0},

0 xuanbo over 7 years ago in reply to Luke Lin

Expert 1550 points

Hi Luke

Thank you for your explaination.
From the default value of AWB registers, the default state is: AWB enabled with auto mode and simple mode.
So i think the default state is enough, we do not need to change the current register value of OV10635, right?

Thanks
xuanbo

0 Luke Lin over 7 years ago in reply to xuanbo

TI__Expert 3250 points

Hi Xuanbo,

Yes, both AWB and AEC are enabled by default. The effect of AWB and AEC can be easily verified by putting the camera under different light source (bright/dark, white/yellow).

Regarding to your question, you may try manual WB and EC. Use the same WB and EC parameters for 4 cameras. This can eliminate the color/brightness difference between cameras.

0 xuanbo over 7 years ago in reply to Luke Lin

Expert 1550 points

Hi Luke

OK, i got it, i will try the manual WB and EC model.
I am sorry that i am not familiar with WB and EC parameters setting right now. So could you give me a example about how to set the WB and EC register values for manual mode correctly?

Thanks
xuanbo

0 xuanbo over 7 years ago in reply to Luke Lin

Expert 1550 points

Hi Luke

And i also test the camera at bright/dark light source: (Image come from ISSCapture)

Bright light source:

Dark light source:

As you see, when the light source is changed to dark, the image captured by camera sensor become brighter.

0 Luke Lin over 7 years ago in reply to xuanbo

TI__Expert 3250 points

Hi Xuanbo,

Sorry, I don't have the example. Suggest contacting OV to get help.

0 xuanbo over 7 years ago in reply to Luke Lin

Expert 1550 points

Hi Luke

OK, i will contact OV to get help, thank you very much.

Thanks
xuanbo

0 Sujith over 7 years ago in reply to xuanbo

TI__Genius 12455 points

Hi Xuanbo,

Seems like AE is functional, can you ensure same lens module is used for all cameras?
Also, check if there are minutes gaps between the lens mount and sensor board.

Regards,
Sujith

0 xuanbo over 7 years ago in reply to Sujith

Expert 1550 points

Hi Sujith

Yes, 4 cameras use the same lens module which come from the same supplier.

Thanks

xuanbo

0 Sujith over 7 years ago in reply to xuanbo

TI__Genius 12455 points

Hi Xuanbo,

Okay, please talk to OV. I hope have checked for light leakage via the gap between lens module and sensor board.

Regards,
Sujith

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TDA2EG: SRV Photometric alignment adjustment Issue