FisheyeFilter.java revision 6570ec1c3edb8071446791001872d8ba87659200
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 17 18package android.filterpacks.imageproc; 19 20import android.filterfw.core.Filter; 21import android.filterfw.core.FilterContext; 22import android.filterfw.core.Frame; 23import android.filterfw.core.FrameFormat; 24import android.filterfw.core.GenerateFieldPort; 25import android.filterfw.core.KeyValueMap; 26import android.filterfw.core.NativeProgram; 27import android.filterfw.core.NativeFrame; 28import android.filterfw.core.Program; 29import android.filterfw.core.ShaderProgram; 30import android.filterfw.format.ImageFormat; 31 32import android.util.Log; 33 34import java.lang.Math; 35import java.util.Set; 36 37/** 38 * @hide 39 */ 40public class FisheyeFilter extends Filter { 41 private static final String TAG = "FisheyeFilter"; 42 43 // This parameter has range between 0 and 1. It controls the effect of radial distortion. 44 // The larger the value, the more prominent the distortion effect becomes (a straight line 45 // becomes a curve). 46 @GenerateFieldPort(name = "scale") 47 private float mScale; 48 49 @GenerateFieldPort(name = "tile_size", hasDefault = true) 50 private int mTileSize = 640; 51 52 private Program mProgram; 53 54 private int mWidth = 0; 55 private int mHeight = 0; 56 private int mTarget = FrameFormat.TARGET_UNSPECIFIED; 57 58 private static final String mFisheyeShader = 59 "precision mediump float;\n" + 60 "uniform sampler2D tex_sampler_0;\n" + 61 "uniform vec2 center;\n" + 62 "uniform float alpha;\n" + 63 "uniform float bound;\n" + 64 "uniform float radius2;\n" + 65 "uniform float factor;\n" + 66 "uniform float inv_height;\n" + 67 "uniform float inv_width;\n" + 68 "varying vec2 v_texcoord;\n" + 69 "void main() {\n" + 70 " const float m_pi_2 = 1.570963;\n" + 71 " float dist = distance(gl_FragCoord.xy, center);\n" + 72 " float radian = m_pi_2 - atan(alpha * sqrt(radius2 - dist * dist), dist);\n" + 73 " float scale = radian * factor / dist;\n" + 74 " vec2 new_coord = gl_FragCoord.xy * scale + (1.0 - scale) * center;\n" + 75 " new_coord.x *= inv_width;\n" + 76 " new_coord.y *= inv_height;\n" + 77 " vec4 color = texture2D(tex_sampler_0, new_coord);\n" + 78 " gl_FragColor = color;\n" + 79 "}\n"; 80 81 public FisheyeFilter(String name) { 82 super(name); 83 } 84 85 @Override 86 public void setupPorts() { 87 addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA)); 88 addOutputBasedOnInput("image", "image"); 89 } 90 91 @Override 92 public FrameFormat getOutputFormat(String portName, FrameFormat inputFormat) { 93 return inputFormat; 94 } 95 96 public void initProgram(FilterContext context, int target) { 97 switch (target) { 98 case FrameFormat.TARGET_GPU: 99 ShaderProgram shaderProgram = new ShaderProgram(context, mFisheyeShader); 100 shaderProgram.setMaximumTileSize(mTileSize); 101 mProgram = shaderProgram; 102 break; 103 104 default: 105 throw new RuntimeException("Filter FisheyeFilter does not support frames of " + 106 "target " + target + "!"); 107 } 108 mTarget = target; 109 } 110 111 @Override 112 public void process(FilterContext context) { 113 // Get input frame 114 Frame input = pullInput("image"); 115 FrameFormat inputFormat = input.getFormat(); 116 117 // Create output frame 118 Frame output = context.getFrameManager().newFrame(inputFormat); 119 120 // Create program if not created already 121 if (mProgram == null || inputFormat.getTarget() != mTarget) { 122 initProgram(context, inputFormat.getTarget()); 123 } 124 125 // Check if the frame size has changed 126 if (inputFormat.getWidth() != mWidth || inputFormat.getHeight() != mHeight) { 127 updateFrameSize(inputFormat.getWidth(), inputFormat.getHeight()); 128 } 129 130 // Process 131 mProgram.process(input, output); 132 133 // Push output 134 pushOutput("image", output); 135 136 // Release pushed frame 137 output.release(); 138 } 139 140 @Override 141 public void fieldPortValueUpdated(String name, FilterContext context) { 142 if (mProgram != null) { 143 updateProgramParams(); 144 } 145 } 146 147 private void updateFrameSize(int width, int height) { 148 float center[] = {0.5f * width, 0.5f * height}; 149 150 mProgram.setHostValue("center", center); 151 mProgram.setHostValue("inv_width", 1.0f / width); 152 mProgram.setHostValue("inv_height", 1.0f / height); 153 154 mWidth = width; 155 mHeight = height; 156 157 updateProgramParams(); 158 } 159 160 private void updateProgramParams() { 161 final float pi = 3.14159265f; 162 163 float alpha = mScale * 2.0f + 0.75f; 164 float bound2 = 0.25f * (mWidth * mWidth + mHeight * mHeight); 165 float bound = (float) Math.sqrt(bound2); 166 float radius = 1.15f * bound; 167 float radius2 = radius * radius; 168 float max_radian = 0.5f * pi - 169 (float) Math.atan(alpha / bound * (float) Math.sqrt(radius2 - bound2)); 170 float factor = bound / max_radian; 171 172 mProgram.setHostValue("radius2",radius2); 173 mProgram.setHostValue("factor", factor); 174 mProgram.setHostValue("alpha", (float) (mScale * 2.0 + 0.75)); 175 } 176 177 178} 179