public PngImagingParameters setForceTrueColor(final boolean forceTrueColor) {
        this.forceTrueColor = forceTrueColor;
        return asThis();
    }
Indicates that the PNG write operation should enable the predictor.

@return true if the predictor is enabled; otherwise, false.
src/main/java/org/apache/commons/imaging/formats/png/PngImagingParameters.java