Image format from capture by CSI Camera

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Hi,

I have a question about image bit depth or color space converter when using CSI camera.
My platform is Jetson Nano, JetPack 4.6.1, CSI Camera: IMX219/IMX477/Imx412.
And refer this example and modify for execise:
/usr/src/jetson_multimedia_ap/argus/samples/oneShot

When using iSensorMode to get sensor image information as:
getBayerPhase is BAYER_PHASE_RGGB
getInputBitDepth is 10
getOutputBitDepth is 10

And line 128 in main.cpp, it seems set output pixel format as YCbCr_420_888
iEGLStreamSettings->setPixelFormat(Argus::PIXEL_FMT_YCbCr_420_888);

*YCbCr_420_888: android - YUV_420_888 (byte) format - Stack Overflow ?

In my thinking, EGL Stream will converter Bayer pattern(10-bit) to YCbCr_420_888 automatically after iSession->capture() and get image from iFrame->getImage()

Is it correct?

And how does it convet 10bit to 8bit? Reserve high 8 bits and ignore others?

3

Nope, Argus::PIXEL_FMT_YCbCr_420_888 is output configure. It’s the configuration of the ISP output format.

4

Thanks for reply.

So let me confirm it :
The image captured by CSI camera is raw bayer format and be sent to internal ISP to do demosaic to RGB and convert to YUV output?

5

Yes, that’s correct.

6

If require lossless compression image, may I use these settings:

PIXEL_FMT_YCbCr_422_888
PIXEL_FMT_YCbCr_444_888

And, may I get original raw bayer format under this setting?

PIXEL_FMT_RAW16

Thanks~

7

Nope,

  • Current EGLStream Buffer Format Support:

    Format State
    ======================= ==========
    PIXEL_FMT_Y8 Not Supported
    PIXEL_FMT_Y16 Not Supported
    PIXEL_FMT_YCbCr_420_888 Works with all consumers.
    PIXEL_FMT_YCbCr_422_888 Not Supported
    PIXEL_FMT_YCbCr_444_888 Not Supported
    PIXEL_FMT_JPEG_BLOB Not Supported (TODO: Remove format)
    PIXEL_FMT_RAW16 Works with all consumers.

8

Hi

Is it any possible or plan to support RGB888 format directly?

9

No plan for Argus, due to ISP HW don’t support it.

10

I can get correct image(format: “PIXEL_FMT_YCbCr_420_888”), but still want to retrive data in raw bayer format.

So I refer to this links:

Detailed Guide to LibArgus with SurveilsQuad (e-consystems.com)

Jetson nano 获取CSI相机RAW图片并转换为Mat | YangYouji’s WebSite

To change format from PIXEL_FMT_YCbCr_420_888 to PIXEL_FMT_RAW16 as follows:

iEGLStreamSettings->setPixelFormat(Argus::PIXEL_FMT_RAW16);

But run to failure at :

Argus::UniqueObjEGLStream::Frame frame(
iFrameConsumer->acquireFrame(FIVE_SECONDS_IN_NANOSECONDS, &status));

=> because of status is “STATUS_TIMEOUT”

Do you know what happens?

11

Have a try the cudaBayerDemosaic in MMAPI sample code.

12

Are those examples unavailable?

I will try “cudaBayerDemosaic” later and reply result to you.
Thanks

13

This example can run correctly and show image on screen.
But something wrong when I try to put image to VPI.

I open another topic to discuss:

How do I get image from cudaBayerDemosaic and connect to VPI? - Jetson & Embedded Systems / Jetson Nano - NVIDIA Developer Forums

15

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