Francisco Durdin Garcia Francisco Durdin Garcia - 11 months ago 57
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 Source

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);
}