IMX335 Camera Image Quality Issues on STM32MP257F-DK

[koushik]

Working with STM32MP257F-DK + IMX335 camera + Quectel EG916Q-GL modem. Successfully recording to eMMC but facing image quality issues:Yellowish tint, Overexposure, White lines in recorded video

Videobalance settings (brightness=0.2, contrast=1.2, saturation=0.9) improve live preview but not the recorded output.

Has anyone experienced similar issues or can recommend optimal IMX335 calibration settings for this hardware combination? Looking for solutions specific to recorded video quality.

Thanks!

[PatrickF]

Hi @koushik 

In RM0457, the ISP demosaicing (raw bayer conversion) inside STM32MP25 is stated as :

"The module works on the pixel pipes, and implements a mid-quality conversion from raw Bayer 8 bpp to an RGB 24 bpp, with no implicit half-sizing: the output RGB pixel rate is the same as the input component rate.
The conversion targets real-time but medium quality purposes, like display or low-resolution software analysis. For higher quality conversions, it is recommended to convert the raw Bayer in software, with higher quality algorithms but limited to non-real-time, thus still-picture applications."

"Note: This demosaicing conversion algorithm can create some artifacts, like Zipper. Such artifacts
are much reduced by a later downsizing or even suppressed for a 2 x 2 downsizing.
Applications like display, video encode, or software analysis usually require such a downsize, so the artifacts become invisible."

 

Main target of camera interface of STM32MP25 is AI analysis, especially when using a raw bayer sensor and internal ISP.

 

In your final product, which probably will use a different camera module, you might get better image by using https://wiki.st.com/stm32mpu/wiki/X-LINUX-ISP_Tool

 

Did you try latest ecosystem 6.0.3 ?

 

Regards.

 

[koushik]

Yes. we are currently using ecosystem 6.0.3