PIXEL_FMT_YCbCr_420_888 to Y plane extraction shows garbage

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
#1

When trying to extract the Y plane from the YCbCr Image I am seeing nothing but corrupted images. The buffer being mapped to CPU with iimage->mapBuffer(0) is larger than the stream resolution of my image. Is the pixel layout different than what I found here on https://en.wikipedia.org/wiki/YUV#Y%E2%80%B2UV420sp_(NV21)to_RGB_conversion(Android)?

#2

Hi jpk1217,

Which platform you’re using? please provide more details of BSP, sensor information.

Thanks

#3

hello jpk1217,

the wiki-page you referred to is the standard picture format on “Android” camera preview.
please note that, JetPack release were based-on L4T, the default color format is NvBufferColorFormat_YUV420.

please refer to Multimedia API Sample Applications for the samples to access your camera sensor, you could also modify the code to have implementation.

besides your platform/ BSP/ sensor information, may I know what’s the purpose to extract Y plan?
thanks

#4

I am using the Jetson AGX Xavier, L4T 31.1, JetPack 4.1 with a Leopard Imaging IMX477 mipi module and carrier board. I will also be trying to use a TX2 with L4T 28.2 and the same camera. I am using libargus to capture frames from the module.

At the time, the use was to view the greyscale image, but the longer goal is to convert from NvBufferColorFormat_YUV420 to RGB32. I am currently using 07_video_convert as a basis after your recommendation.

#5