TDA4AL-Q1: Conception clarification for ISP tuning parameter

Gibbs Shih

Expert 5345 points

Part Number: TDA4AL-Q1

Tool/software:

Dear Expert,

This question is query from customer.

Base on real ADAS vision application w/ camera in real word, it seems need "multiple ISP tuning parameter" for camera.

For example, it may need different AE/AWB setting in day and night.

But I try to study ISP tuning guide, it seems focus special (standard) test environment, not real word.

My question.

(1) Does it have any way to distinguish day and night for ISP w/ camera data input?

(2) Is it reasonable to have multiple ISP tuning parameter for day and night scene in ADAS application.

If the answer is yes, Do we have any concept to implement it?

Thank You.

Gibbs

2 days ago

+1 Gang Hua 2 days ago

TI__Guru 59740 points

Hi Gibbs,

Gibbs Shih said:
Base on real ADAS vision application w/ camera in real word, it seems need "multiple ISP tuning parameter" for camera.

Yes, that may be required for real ADAS applications.

Gibbs Shih said:
For example, it may need different AE/AWB setting in day and night.

TI AE/AWB in SDK are for reference and demo and they are not production-ready.
TI AE and AWB do not have separate settings or calibration for day and night scenes.

Gibbs Shih said:
(1) Does it have any way to distinguish day and night for ISP w/ camera data input?

It is possible to distinguish day and night based on the AE output of sensor exposure time and gain, e.g., high expose time and gain indicate night scenes.

Gibbs Shih said:
(2) Is it reasonable to have multiple ISP tuning parameter for day and night scene in ADAS application.

Different tuning parameters may be applied to ISP according to 2A output (e.g., exposure time, gain, CCT).
It may be supported by ISP tuning tool and DCC s/w in SDK.

https://git.ti.com/cgit/processor-sdk/imaging/tree/sensor_drv/src/ox05b1s/dcc_xmls/linear/OX05B1S_viss_nsf4.xml#n49
https://git.ti.com/cgit/processor-sdk/imaging/tree/sensor_drv/src/ox05b1s/dcc_xmls/linear/OX05B1S_rgb2rgb_dcc.xml#n28

For example, in the links above, there are a few sets of parameters based on the sensor gain or CCT output from AE/AWB.

0 Gibbs Shih 1 day ago in reply to Gang Hua

TI__Expert 5345 points

Hi, Gang Hua

Thanks your replies.

I am try to also study some thread.

I think concept should be like,

Step1, Every sensor has minimum and maximum exposure time and analog gain which it operates within. we must base on camera's spec to stuff in right parameter in code, example like.

[FAQ] AM62A7: How to Set the Minimum/Maximum Exposure Time and Analog Gain for 2A Algorithm?

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1262114/faq-setting-up-auto-exposure-ae-for-your-image-sensor-with-tda4-am6xa-isp-vpac/5434969?tisearch=e2e-sitesearch&keymatch=faq%20auto%20exposure#

Step 2. Use some SW API to get current exposure time (or gain) from AE (2A), and then we can distinguish day and night.

Step3, Base on different 2A output in day and night, we may applied different ISP tuning parameter to camera. We can use ISP tuning tool and DCC s/w to help us analysis/tuning/implement related function.

If something is wrong, pls direct correct me.

Thank You Very Much

Gibbs

+1 Gang Hua 1 day ago in reply to Gibbs Shih

TI__Guru 59740 points

Hi Gibbs,

Gibbs Shih said:
I think concept should be like,

Yes, that is the right idea.

Gibbs Shih said:
Step1, Every sensor has minimum and maximum exposure time and analog gain

This step is for setting up TI's reference AE correctly for a sensor.

Gibbs Shih said:
Step 2. Use some SW API to get current exposure time (or gain) from AE (2A)

This step is done by tiovx AE/AWB kernel and the results are sent to the tiovx VISS kernel in camera apps.

Gibbs Shih said:
Step3, Base on different 2A output in day and night, we may applied different ISP tuning parameter to camera

This could be done in the VISS kernel as you can see in https://git.ti.com/cgit/processor-sdk/imaging/tree/kernels/hwa/vpac_viss/vx_vpac_viss_target_dcc.c#n283

These are sample tuning data processing and customers may customize and extend the VISS kernel and DCC source code for their own applications.

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TDA4AL-Q1: Conception clarification for ISP tuning parameter