public static void setInvertColor(Camera.Parameters parameters) {
        if (Camera.Parameters.EFFECT_NEGATIVE.equals(parameters.getColorEffect())) {
            Log.i(TAG, "Negative effect already set");
            return;
        }
        String colorMode = findSettableValue("color effect",
                parameters.getSupportedColorEffects(),
                Camera.Parameters.EFFECT_NEGATIVE);
        if (colorMode != null) {
            parameters.setColorEffect(colorMode);
        }
    }
Utility methods for configuring the Android camera.

@author Sean Owen
zxing-android-embedded/src/com/journeyapps/barcodescanner/camera/CameraConfigurationUtils.java