| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.filterpacks.imageproc; |
| |
| import android.filterfw.core.Filter; |
| import android.filterfw.core.FilterContext; |
| import android.filterfw.core.Frame; |
| import android.filterfw.core.FrameFormat; |
| import android.filterfw.core.GenerateFieldPort; |
| import android.filterfw.core.Program; |
| import android.filterfw.core.ShaderProgram; |
| import android.filterfw.format.ImageFormat; |
| |
| import java.util.Date; |
| import java.util.Random; |
| |
| public class BlackWhiteFilter extends Filter { |
| |
| @GenerateFieldPort(name = "black", hasDefault = true) |
| private float mBlack = 0f; |
| |
| @GenerateFieldPort(name = "white", hasDefault = true) |
| private float mWhite = 1f; |
| |
| @GenerateFieldPort(name = "tile_size", hasDefault = true) |
| private int mTileSize = 640; |
| |
| private Program mProgram; |
| private Random mRandom; |
| |
| private int mTarget = FrameFormat.TARGET_UNSPECIFIED; |
| |
| private final String mBlackWhiteShader = |
| "precision mediump float;\n" + |
| "uniform sampler2D tex_sampler_0;\n" + |
| "uniform vec2 seed;\n" + |
| "uniform float black;\n" + |
| "uniform float scale;\n" + |
| "uniform float stepsize;\n" + |
| "varying vec2 v_texcoord;\n" + |
| "float rand(vec2 loc) {\n" + |
| // Compute sin(theta), theta = 12.9898 x + 78.233y |
| // because floating point has limited range, make theta = theta1 + theta2 |
| // where theta1 = 12x + 78y and theta2 = 0.9898x + 0.233y) |
| // Note that theta1 and theta2 cover diffent range of theta. |
| " float theta1 = dot(loc, vec2(0.9898, 0.233));\n" + |
| " float theta2 = dot(loc, vec2(12.0, 78.0));\n" + |
| // Use the property sin(theta) = cos(theta1)*sin(theta2)+sin(theta1)*cos(theta2) |
| // this approach also increases the precisions of sin(theta) |
| " float value = cos(theta1) * sin(theta2) + sin(theta1) * cos(theta2);\n" + |
| // fract(43758.5453 * x) = fract(43758 * x + 0.5453 * x) |
| // keep value of part1 in range: (2^-14 to 2^14). Since 43758 = 117 * 374 |
| // fract(43758 * sin(theta)) = mod(221 * mod(198*sin(theta), 1.0), 1.0) |
| // also to keep as much decimal digits, use the property |
| // mod(mod(198*sin(theta)) = mod(mod(197*sin(theta) + sin(theta)) |
| " float temp = mod(197.0 * value, 1.0) + value;\n" + |
| " float part1 = mod(220.0 * temp, 1.0) + temp;\n" + |
| " float part2 = value * 0.5453;\n" + |
| " float part3 = cos(theta1 + theta2) * 0.43758;\n" + |
| " return fract(part1 + part2 + part3);\n" + |
| "}\n" + |
| "void main() {\n" + |
| " vec4 color = texture2D(tex_sampler_0, v_texcoord);\n" + |
| " float dither = rand(v_texcoord + seed);\n" + |
| " vec3 xform = clamp((color.rgb - black) * scale, 0.0, 1.0);\n" + |
| " vec3 temp = clamp((color.rgb + stepsize - black) * scale, 0.0, 1.0);\n" + |
| " vec3 new_color = clamp(xform + (temp - xform) * (dither - 0.5), 0.0, 1.0);\n" + |
| " gl_FragColor = vec4(new_color, color.a);\n" + |
| "}\n"; |
| |
| public BlackWhiteFilter(String name) { |
| super(name); |
| mRandom = new Random(new Date().getTime()); |
| } |
| |
| @Override |
| public void setupPorts() { |
| addMaskedInputPort("image", ImageFormat.create(ImageFormat.COLORSPACE_RGBA)); |
| addOutputBasedOnInput("image", "image"); |
| } |
| |
| @Override |
| public FrameFormat getOutputFormat(String portName, FrameFormat inputFormat) { |
| return inputFormat; |
| } |
| |
| public void initProgram(FilterContext context, int target) { |
| switch (target) { |
| case FrameFormat.TARGET_GPU: |
| ShaderProgram shaderProgram = new ShaderProgram(context, mBlackWhiteShader); |
| shaderProgram.setMaximumTileSize(mTileSize); |
| mProgram = shaderProgram; |
| updateParameters(); |
| break; |
| |
| default: |
| throw new RuntimeException("Filter Sharpen does not support frames of " + |
| "target " + target + "!"); |
| } |
| mTarget = target; |
| } |
| |
| private void updateParameters() { |
| float scale = (mBlack != mWhite) ? 1.0f / (mWhite - mBlack) : 2000f; |
| float stepsize = 1.0f / 255.0f; |
| mProgram.setHostValue("black", mBlack); |
| mProgram.setHostValue("scale", scale); |
| mProgram.setHostValue("stepsize", stepsize); |
| |
| float seed[] = { mRandom.nextFloat(), mRandom.nextFloat() }; |
| mProgram.setHostValue("seed", seed); |
| } |
| |
| @Override |
| public void fieldPortValueUpdated(String name, FilterContext context) { |
| if (mProgram != null) { |
| updateParameters(); |
| } |
| } |
| |
| @Override |
| public void process(FilterContext context) { |
| // Get input frame |
| Frame input = pullInput("image"); |
| FrameFormat inputFormat = input.getFormat(); |
| |
| // Create program if not created already |
| if (mProgram == null || inputFormat.getTarget() != mTarget) { |
| initProgram(context, inputFormat.getTarget()); |
| } |
| |
| // Create output frame |
| Frame output = context.getFrameManager().newFrame(inputFormat); |
| |
| // Process |
| mProgram.process(input, output); |
| |
| // Push output |
| pushOutput("image", output); |
| |
| // Release pushed frame |
| output.release(); |
| } |
| } |