BlackWhiteFilter.java revision f4b403159f8a89eb2158bbb6c314de3bc90fee73 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.filterpacks.imageproc;
18
19import android.filterfw.core.Filter;
20import android.filterfw.core.FilterContext;
21import android.filterfw.core.Frame;
22import android.filterfw.core.FrameFormat;
23import android.filterfw.core.GenerateFieldPort;
24import android.filterfw.core.KeyValueMap;
25import android.filterfw.core.NativeProgram;
26import android.filterfw.core.NativeFrame;
27import android.filterfw.core.Program;
28import android.filterfw.core.ShaderProgram;
29import android.filterfw.format.ImageFormat;
30
31import java.util.Random;
32
33public class BlackWhiteFilter extends Filter {
34
35    @GenerateFieldPort(name = "black", hasDefault = true)
36    private float mBlack = 0f;
37
38    @GenerateFieldPort(name = "white", hasDefault = true)
39    private float mWhite = 1f;
40
41    @GenerateFieldPort(name = "tile_size", hasDefault = true)
42    private int mTileSize = 640;
43
44    private Program mProgram;
45
46    private int mWidth = 0;
47    private int mHeight = 0;
48    private int mTarget = FrameFormat.TARGET_UNSPECIFIED;
49
50    private final String mBlackWhiteShader =
51            "precision mediump float;\n" +
52            "uniform sampler2D tex_sampler_0;\n" +
53            "uniform float black;\n" +
54            "uniform float scale;\n" +
55            "uniform float stepsize;\n" +
56            "varying vec2 v_texcoord;\n" +
57            "float rand(vec2 loc) {\n" +
58            "  return fract(sin(dot(loc, vec2(12.9898, 78.233))) * 43758.5453);\n" +
59            "}\n" +
60            "void main() {\n" +
61            "  vec4 color = texture2D(tex_sampler_0, v_texcoord);\n" +
62            "  float dither = rand(v_texcoord);\n" +
63            "  vec3 xform = clamp((color.rgb - black) * scale, 0.0, 1.0);\n" +
64            "  vec3 temp = clamp((color.rgb + stepsize - black) * scale, 0.0, 1.0);\n" +
65            "  vec3 new_color = clamp(xform + (temp - xform) * (dither - 0.5), 0.0, 1.0);\n" +
66            "  gl_FragColor = vec4(new_color, color.a);\n" +
67            "}\n";
68
69    public BlackWhiteFilter(String name) {
70        super(name);
71    }
72
73    @Override
74    public void setupPorts() {
75        addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA));
76        addOutputBasedOnInput("image", "image");
77    }
78
79    @Override
80    public FrameFormat getOutputFormat(String portName, FrameFormat inputFormat) {
81        return inputFormat;
82    }
83
84    public void initProgram(FilterContext context, int target) {
85        switch (target) {
86            case FrameFormat.TARGET_GPU:
87                ShaderProgram shaderProgram = new ShaderProgram(context, mBlackWhiteShader);
88                shaderProgram.setMaximumTileSize(mTileSize);
89                mProgram = shaderProgram;
90                updateParameters();
91                break;
92
93            default:
94                throw new RuntimeException("Filter Sharpen does not support frames of " +
95                    "target " + target + "!");
96        }
97        mTarget = target;
98    }
99
100    private void updateParameters() {
101        float scale = (mBlack != mWhite) ? 1.0f / (mWhite - mBlack) : 2000f;
102        float stepsize = 1.0f / 255.0f;
103
104        mProgram.setHostValue("black", mBlack);
105        mProgram.setHostValue("scale", scale);
106        mProgram.setHostValue("stepsize", stepsize);
107    }
108
109    @Override
110    public void fieldPortValueUpdated(String name, FilterContext context) {
111        if (mProgram != null) {
112            updateParameters();
113        }
114    }
115
116    @Override
117    public void process(FilterContext context) {
118        // Get input frame
119        Frame input = pullInput("image");
120        FrameFormat inputFormat = input.getFormat();
121
122        // Create program if not created already
123        if (mProgram == null || inputFormat.getTarget() != mTarget) {
124            initProgram(context, inputFormat.getTarget());
125        }
126
127        // Check if the frame size has changed
128        if (inputFormat.getWidth() != mWidth || inputFormat.getHeight() != mHeight) {
129            mWidth = inputFormat.getWidth();
130            mHeight = inputFormat.getHeight();
131        }
132
133        // Create output frame
134        Frame output = context.getFrameManager().newFrame(inputFormat);
135
136        // Process
137        mProgram.process(input, output);
138
139        // Push output
140        pushOutput("image", output);
141
142        // Release pushed frame
143        output.release();
144    }
145}
146