src/main/java/org/gm4java/im4java/GMOperation.java
public GMOperation quality(double quality) {
        final List<String> args = getCmdArgs();
        args.add("-quality");
        args.add(Double.toString(quality));
        return this;
    }
public GMOperation quality(double quality) {
        final List<String> args = getCmdArgs();
        args.add("-quality");
        args.add(Double.toString(quality));
        return this;
    }
Add option -quality to the GraphicsMagick commandline (see the documentation of GraphicsMagick for details).

@param quality
the quality of the image from 0 - 100
@return Builder object for chained options setup