001    /*
002    *
003    
004    Licensed under the Apache License, Version 2.0 (the "License");
005    you may not use this file except in compliance with the License.
006    You may obtain a copy of the License at
007    
008       http://www.apache.org/licenses/LICENSE-2.0
009    
010    Unless required by applicable law or agreed to in writing, software
011    distributed under the License is distributed on an "AS IS" BASIS,
012    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013    See the License for the specific language governing permissions and
014    limitations under the License.
015    */
016    
017    package railo.runtime.img.filter;import java.awt.image.BufferedImage;
018    
019    import railo.runtime.engine.ThreadLocalPageContext;
020    import railo.runtime.exp.FunctionException;
021    import railo.runtime.exp.PageException;
022    import railo.runtime.img.ImageUtil;
023    import railo.runtime.type.KeyImpl;
024    import railo.runtime.type.List;
025    import railo.runtime.type.Struct;
026    
027    
028    
029    /**
030     * A filter which changes the gain and bias of an image - similar to ContrastFilter.
031     */
032    public class GainFilter extends TransferFilter  implements DynFiltering {
033    
034            private float gain = 0.5f;
035            private float bias = 0.5f;
036            
037            protected float transferFunction( float f ) {
038                    f = ImageMath.gain(f, gain);
039                    f = ImageMath.bias(f, bias);
040                    return f;
041            }
042    
043        /**
044         * Set the gain.
045         * @param gain the gain
046         * @min-value: 0
047         * @max-value: 1
048         * @see #getGain
049         */
050            public void setGain(float gain) {
051                    this.gain = gain;
052                    initialized = false;
053            }
054            
055        /**
056         * Get the gain.
057         * @return the gain
058         * @see #setGain
059         */
060            public float getGain() {
061                    return gain;
062            }
063    
064        /**
065         * Set the bias.
066         * @param bias the bias
067         * @min-value: 0
068         * @max-value: 1
069         * @see #getBias
070         */
071            public void setBias(float bias) {
072                    this.bias = bias;
073                    initialized = false;
074            }
075            
076        /**
077         * Get the bias.
078         * @return the bias
079         * @see #setBias
080         */
081            public float getBias() {
082                    return bias;
083            }
084    
085            public String toString() {
086                    return "Colors/Gain...";
087            }
088    
089            public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src);
090                    Object o;
091                    if((o=parameters.removeEL(KeyImpl.init("Gain")))!=null)setGain(ImageFilterUtil.toFloatValue(o,"Gain"));
092                    if((o=parameters.removeEL(KeyImpl.init("Bias")))!=null)setBias(ImageFilterUtil.toFloatValue(o,"Bias"));
093                    if((o=parameters.removeEL(KeyImpl.init("Dimensions")))!=null){
094                            int[] dim=ImageFilterUtil.toDimensions(o,"Dimensions");
095                            setDimensions(dim[0],dim[1]);
096                    }
097    
098                    // check for arguments not supported
099                    if(parameters.size()>0) {
100                            throw new FunctionException(ThreadLocalPageContext.get(), "ImageFilter", 3, "parameters", "the parameter"+(parameters.size()>1?"s":"")+" ["+List.arrayToList(parameters.keysAsString(),", ")+"] "+(parameters.size()>1?"are":"is")+" not allowed, only the following parameters are supported [Gain, Bias, Dimensions]");
101                    }
102    
103                    return filter(src, dst);
104            }
105    }
106