Francisco Durdin Garcia Francisco Durdin Garcia - 1 month ago 12
Android Question

Camera2 API Set Custom White Balance & Temperature Color

Im trying to set a custom value for the White Balance & temperature color in my camera app. Im using camera2 API and Im trying different ways to set this value. I found a method from a excel file to get the right RGB Temperature matrix [Red,Green,Blue] from the White Balance Value between 100 and 100.000.

I attached this method to a Seekbar and its working fine, my problem appear when I try to focus something white, then it becomes pink. Any kind of light looks like a pink torch in the screen.
enter image description here

Im setting the values in this way:

mPreviewRequestBuilder.set(CaptureRequest.COLOR_CORRECTION_MODE, CaptureRequest.COLOR_CORRECTION_MODE_TRANSFORM_MATRIX);

RggbChannelVector rggb = getTemperatureVector(seekBackSelectedTemperature);

mPreviewRequestBuilder.set(CaptureRequest.COLOR_CORRECTION_GAINS, myRggbChannelVector);


In other way, my method to get the matrix is this one:

public static RggbChannelVector getTemperatureVector (int WhiteBalanceValue){


float InsertTemperature = WhiteBalanceValue;
float temperature = InsertTemperature / 100;
float red;
float green;
float blue;

//Calculate red

if (temperature <= 66)
red = 255;
else {
red = temperature - 60;
red = (float) (329.698727446 * (Math.pow((double) red, -0.1332047592)));
if (red < 0)
red = 0;
if (red > 255)
red = 255;
}


//Calculate green
if (temperature <= 66) {
green = temperature;
green = (float) (99.4708025861 * Math.log(green) - 161.1195681661);
if (green < 0)
green = 0;
if (green > 255)
green = 255;
} else
green = temperature - 60;
green = (float) (288.1221695283 * (Math.pow((double) red, -0.0755148492)));
if (green < 0)
green = 0;
if (green > 255)
green = 255;


//calculate blue
if (temperature >= 66)
blue = 255;
else if (temperature <= 19)
blue = 0;
else {
blue = temperature - 10;
blue = (float) (138.5177312231 * Math.log(blue) - 305.0447927307);
if (blue < 0)
blue = 0;
if (blue > 255)
blue = 255;
}
RggbChannelVector finalTemperatureValue = new RggbChannelVector(red/255,(green/255)/2,(green/255)/2,blue/255);
return finalTemperatureValue;
}


Maybe its cause the method of my CaptureRequest is not correct, but I dont find the way to fix it. Hope that someone have some idea about it!

Thank you very much in advance.

Answer

It worked after change the template to Still_capture or Manual Template and use the next method:

 captureBuilder.set(CaptureRequest.CONTROL_AWB_MODE, CaptureRequest.CONTROL_AWB_MODE_OFF);
        // adjust color correction using seekbar's params
        captureBuilder.set(CaptureRequest.COLOR_CORRECTION_MODE, CaptureRequest.COLOR_CORRECTION_MODE_TRANSFORM_MATRIX);
        captureBuilder.set(CaptureRequest.COLOR_CORRECTION_GAINS, CameraCapabilities.colorTemperature(Integer.parseInt(awbMode)));

public static RggbChannelVector colorTemperature(int whiteBalance) {
    float temperature = whiteBalance / 100;
    float red;
    float green;
    float blue;

    //Calculate red
    if (temperature <= 66)
        red = 255;
    else {
        red = temperature - 60;
        red = (float) (329.698727446 * (Math.pow((double) red, -0.1332047592)));
        if (red < 0)
            red = 0;
        if (red > 255)
            red = 255;
    }


    //Calculate green
    if (temperature <= 66) {
        green = temperature;
        green = (float) (99.4708025861 * Math.log(green) - 161.1195681661);
        if (green < 0)
            green = 0;
        if (green > 255)
            green = 255;
    } else {
        green = temperature - 60;
        green = (float) (288.1221695283 * (Math.pow((double) green, -0.0755148492)));
        if (green < 0)
            green = 0;
        if (green > 255)
            green = 255;
    }

    //calculate blue
    if (temperature >= 66)
        blue = 255;
    else if (temperature <= 19)
        blue = 0;
    else {
        blue = temperature - 10;
        blue = (float) (138.5177312231 * Math.log(blue) - 305.0447927307);
        if (blue < 0)
            blue = 0;
        if (blue > 255)
            blue = 255;
    }

    Log.v(TAG, "red=" + red + ", green=" + green + ", blue=" + blue);
    return new RggbChannelVector((red / 255) * 2, (green / 255), (green / 255), (blue / 255) * 2);
}