Color Control Matrix and Tone Curves in camera_override.isp

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

I am working on a Jetson Nano module on a custom carrier board connected to 2 x Sony IMX415 sensors.
I need to customize the camera_override.isp file to include:

  • a Color Correction Matrix

  • a Tone Curve for each RGB color channel

I discovered that it is quite simple to add the color correction matrix such as:

colorCorrection.srgbMatrix[0] = { 1.5662, -0.3302, 0.0268};
colorCorrection.srgbMatrix[1] = { -0.5544, 1.8120, -0.8347};
colorCorrection.srgbMatrix[2] = { -0.0118, -0.4818, 1.8079};

What is not clear is how to input the tone curves.
Apparently each curve is as follow:
tc.v2.user.presets[0].Gamma.Value=2.4000;
tc.v2.user.presets[0].UserCurve.Enable=FALSE;
tc.v2.user.presets[0].UserCurve.Points={ 0.0000, 0.0000, 0.2500, 0.2500, 0.5000, 0.5000, 0.7500, 0.7500, 1.0000, 1.0000 };
tc.v2.user.presets[0].CurveControl.Enable=TRUE;
tc.v2.user.presets[0].CurveControl.AdjustHighlights=0.7500;
tc.v2.user.presets[0].CurveControl.MidtoneBrightness=0.5000;
tc.v2.user.presets[0].CurveControl.MidtoneContrast=0.5000;
tc.v2.user.presets[0].CurveControl.AdjustShadows=0.2500;
tc.v2.user.presets[0].Brightness.Enable=FALSE;
tc.v2.user.presets[0].Brightness.Value=1.0000;

There are 9 element in the tc.v2.user.preset vector and I don’t know for which RGB channel are applicable.

These other parameters are undocumented:

  • are such parameters mandatory ?
  • or optional ?
  • which is the meaning ?

tc.v2.user.UseIndices={ 0, 0, 0, 0, 0, 0, 0, 0, 0 };
tc.v2.user.FlashUseIndices= { 0, 0, 0, 0, 0, 0, 0, 0, 0 };
tc.v2.UseAxisX={ 1068.0000, 2136.0000, 9970.0000, 14242.0000 };
tc.v2.UseAxisY={ 1.0000, 1.0000, 1.0000, 1.0000 };
tc.v2.FlashUseAxisX={ 1068.0000, 2136.0000, 9970.0000, 14242.0000 };
tc.v2.FlashUseAxisY={ 1.0000, 1.0000, 1.0000, 1.0000 };
tc.v2.initStats.brightness=3811;
tc.v2.initStats.tcdre=1.0;

Thanks

Andrea

3

Please consult the ISP tuning problem with scaling partner.

4

You should be able to use the argus API for the CCM and tone map instead of the override file.

Have a check below API in the multimedia API document.

Argus::IAutoControlSettings::setColorCorrectionMatrix() and Argus::IAutoControlSettings::setToneMapCurve(),

5

Are there any examples ?
I didn’t find any specific example in the Multimedia samples.
Thanks

Andrea

6

Have a check these code snippet.

const float r0[] = {1.1f, 0.0f, 0.0f};
const float r1[] = {0.0f, 0.9f, 0.0f};
const float r2[] = {0.0f, 0.0f, 1.2f};

std::vector<float> testColorCorrectionMatrix = getVectorMatrix(r0, r1, r2);
std::vector<float> testInvalidColorCorrectionMatrix = getVectorMatrix(r0, r1, r2);
setColorCorrectionMatrix(testColorCorrectionMatrix));


{
	float toneval[129]=
		{0.000000,
		0.056696,
		0.112414,
		0.159335,
		0.193548,
		0.226784,
		0.254154,
		0.282502,
		0.304008,
		0.324536,
		0.346041,
		0.364614,
		0.384164,
		0.399805,
		0.416422,
		0.431085,
		0.443793,
		0.457478,
		0.471163,
		0.481916,
		0.494624,
		0.506354,
		0.517107,
		0.529814,
		0.542522,
		0.555230,
		0.566960,
		0.577713,
		0.588465,
		0.599218,
		0.609971,
		0.619746,
		0.629521,
		0.639296,
		0.649071,
		0.657869,
		0.665689,
		0.674487,
		0.682307,
		0.690127,
		0.697947,
		0.705767,
		0.714565,
		0.722385,
		0.730205,
		0.738025,
		0.745846,
		0.753666,
		0.761486,
		0.767351,
		0.773216,
		0.777126,
		0.782014,
		0.786901,
		0.791789,
		0.795699,
		0.800587,
		0.804497,
		0.809384,
		0.813294,
		0.817204,
		0.821114,
		0.825024,
		0.828934,
		0.832845,
		0.836755,
		0.840665,
		0.844575,
		0.847507,
		0.851417,
		0.855327,
		0.858260,
		0.862170,
		0.865103,
		0.869013,
		0.871945,
		0.874878,
		0.878788,
		0.881720,
		0.884653,
		0.887586,
		0.890518,
		0.893451,
		0.896383,
		0.899316,
		0.902248,
		0.905181,
		0.908113,
		0.911046,
		0.913979,
		0.916911,
		0.918866,
		0.921799,
		0.924731,
		0.927664,
		0.929619,
		0.932551,
		0.935484,
		0.937439,
		0.940371,
		0.942326,
		0.945259,
		0.948192,
		0.950147,
		0.952102,
		0.955034,
		0.956989,
		0.959922,
		0.960899,
		0.962854,
		0.965787,
		0.967742,
		0.969697,
		0.972630,
		0.974585,
		0.976540,
		0.978495,
		0.981427,
		0.983382,
		0.985337,
		0.987292,
		0.989247,
		0.991202,
		0.993157,
		0.995112,
		0.997067,
		0.998045,
		0.999022,
		1.000000};
	std::vector<float> curves(129,0);
	uint32_t curve_size;
    IAutoControlSettings *iAutoControlSettings =
        interface_cast<IAutoControlSettings>(iRequest->getAutoControlSettings());

    curve_size = iAutoControlSettings->getToneMapCurveSize(RGB_CHANNEL_R);
    iAutoControlSettings->setToneMapCurveEnable(true);
    for(int cnt = 0; cnt < curve_size;cnt++)
	{
		curves[cnt] = toneval[cnt];
		iAutoControlSettings->setToneMapCurve(RGB_CHANNEL_R, curves);
		iAutoControlSettings->setToneMapCurve(RGB_CHANNEL_G, curves);
		iAutoControlSettings->setToneMapCurve(RGB_CHANNEL_B, curves);

	}
}
1 Like
8

Why is the setToneMapCurve being called in the loop. That doesn’t seem necessary.

1 Like
9

You are right, doesn’t necessary set it in the loop.