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[update by wysaid] Add curve filter. After this commit, the curve filter would not need resource images input any more. Curve algorithm based on Catmull-Rom Spline
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Lines changed: 196 additions & 4 deletions

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‎library/src/jp/co/cyberagent/android/gpuimage/GPUImageBilateralFilter.java‎

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/**
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* @author wysaid
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* @mail admin@wysaid.org
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*
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*/
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package jp.co.cyberagent.android.gpuimage;

‎library/src/jp/co/cyberagent/android/gpuimage/GPUImageCurveFilter.java‎

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/**
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* @author wysaid
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* @mail admin@wysaid.org
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* @refer https://github.com/wysaid/android-gpuimage-plus
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*/
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package jp.co.cyberagent.android.gpuimage;
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import android.opengl.GLES20;
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import java.nio.ByteBuffer;
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public class GPUImageCurveFilter extends GPUImageFilter {
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public static final String CURVE_ADJUST_FRAGMENT_SHADER = "" +
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"precision mediump float;" +
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"varying vec2 textureCoordinate;\n" +
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"uniform sampler2D inputImageTexture;\n" +
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"uniform sampler2D curveTexture; //We do not use sampler1D because GLES dosenot support that.\n" +
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"void main()\n" +
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"{\n" +
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" vec4 src = texture2D(inputImageTexture, textureCoordinate);\n" +
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" gl_FragColor = vec4(texture2D(curveTexture, vec2(src.r, 0.0)).r," +
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" texture2D(curveTexture, vec2(src.g, 0.0)).g," +
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" texture2D(curveTexture, vec2(src.b, 0.0)).b," +
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" src.a);\n" +
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// "gl_FragColor = texture2D(curveTexture, textureCoordinate);" + //for testing
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"}";
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private static int CURVE_PRECISION = 256;
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private int mCurveTexLocation;
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private int mCurveTextureID = 0;
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ByteBuffer mCurveBuffer;
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public GPUImageCurveFilter() {
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super(NO_FILTER_VERTEX_SHADER, CURVE_ADJUST_FRAGMENT_SHADER);
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}
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@Override
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public void onInit() {
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super.onInit();
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GLES20.glUseProgram(getProgram());
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mCurveTexLocation = GLES20.glGetUniformLocation(getProgram(), "curveTexture");
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GLES20.glUniform1i(mCurveTexLocation, 1); //Curve Texture Location is never changed!
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//Generate curve texture
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int[] texID = {0};
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GLES20.glGenTextures(1, texID, 0);
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mCurveTextureID = texID[0];
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GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mCurveTextureID);
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GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
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GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
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GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
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GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
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mCurveBuffer = ByteBuffer.allocate(CURVE_PRECISION * 3);
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resetCurve();
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GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mCurveTextureID);
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GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGB, 256, 1, 0, GLES20.GL_RGB, GLES20.GL_UNSIGNED_BYTE, mCurveBuffer);
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}
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@Override
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public void onDestroy() {
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super.onDestroy();
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GLES20.glDeleteTextures(1, new int[]{mCurveTextureID}, 0);
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}
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@Override
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public void onDrawArraysPre() {
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//As mCurveTexLocation is already set to 1, just bind the tex id to GL_TEXTURE1.
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GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
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GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mCurveTextureID);
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}
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// 'points[RGB]' are paired with x and y, and both range from 0 to 1.
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// If any channel shall stay, pass 'null'.
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public void setCurveByPoints(float[] pointsR, float[] pointsG, float[] pointsB) {
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if(pointsR != null && pointsR.length >= 4)
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setSingleCurve(pointsR, 0);
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if(pointsG != null && pointsG.length >= 4)
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setSingleCurve(pointsG, 1);
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if(pointsB != null && pointsB.length >= 4)
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setSingleCurve(pointsB, 2);
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assignCurve();
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}
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// Algorithm from: https://github.com/wysaid/android-gpuimage-plus
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private void setSingleCurve(float[] pnts, int stride) {
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mCurveBuffer.position(0);
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int cnt = pnts.length / 2;
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float[] u = new float[cnt - 1];
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float[] ypp = new float[cnt];
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ypp[0] = u[0] = 0.0f;
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for(int i=1; i != cnt - 1; ++i)
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{
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int pre = (i - 1) * 2, cur = i * 2, nxt = (i + 1) * 2;
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float sig = (pnts[cur] - pnts[pre]) / (pnts[nxt] - pnts[pre]);
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float p = sig * ypp[i - 1] + 2.0f;
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ypp[i] = (sig - 1.0f) / p;
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u[i] = ((pnts[nxt + 1] - pnts[cur + 1]) / (pnts[nxt] - pnts[cur]) - (pnts[cur + 1] - pnts[pre + 1]) / (pnts[cur] - pnts[pre]));
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u[i] = (6.0f * u[i] / (pnts[nxt] - pnts[pre]) - sig * u[i - 1]) / p;
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}
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ypp[cnt - 1] = 0.0f;
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for(int i = cnt - 2; i >= 0; --i)
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{
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ypp[i] = ypp[i] * ypp[i+1] + u[i];
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}
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int kL = -1, kH = 0;
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byte[] buffer = mCurveBuffer.array();
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for(int i = 0; i != CURVE_PRECISION; ++i)
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{
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float t = (float)i/(CURVE_PRECISION - 1);
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while(kH < cnt && t > pnts[kH * 2])
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{
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kL = kH;
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++kH;
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}
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if(kH == cnt)
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{
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buffer[i * 3 + stride] = (byte) (pnts[(cnt-1) * 2 + 1] * 255);
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continue;
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}
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if(kL == -1)
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{
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buffer[i * 3 + stride] = (byte) (pnts[1] * 255);
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continue;
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}
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float h = pnts[kH * 2] - pnts[kL * 2];
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float a = (pnts[kH * 2] - t) / h;
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float b = (t - pnts[kL * 2]) / h;
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float g = a * pnts[kL * 2 + 1] + b*pnts[kH * 2 + 1] + ((a*a*a - a)*ypp[kL] + (b*b*b - b) * ypp[kH]) * (h*h) / 6.0f;
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float result = Math.min(Math.max(g, 0.0f), 1.0f);
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buffer[i * 3 + stride] = (byte) (result * 255.0f);
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}
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}
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private void resetCurve() {
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mCurveBuffer.position(0);
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byte[] bytes = mCurveBuffer.array();
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for(int i = 0; i < CURVE_PRECISION * 3; i += 3) {
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byte tmp = (byte) (i * 255 / (CURVE_PRECISION * 3));
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bytes[i] = bytes[i + 1] = bytes[i + 2] = tmp;
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}
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}
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private void assignCurve() {
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mCurveBuffer.position(0);
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runOnDraw(new Runnable() {
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@Override
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public void run() {
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GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
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GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mCurveTextureID);
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GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGB, 256, 1, 0, GLES20.GL_RGB, GLES20.GL_UNSIGNED_BYTE, mCurveBuffer);
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}
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});
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}
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}

‎sample/src/jp/co/cyberagent/android/gpuimage/sample/GPUImageFilterTools.java‎

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Original file line numberDiff line numberDiff line change
@@ -106,7 +106,8 @@ public static void showDialog(final Context context,
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filters.addFilter("Levels Min (Mid Adjust)", FilterType.LEVELS_FILTER_MIN);
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filters. addFilter("Bilateral Blur", FilterType.BILATERAL_BLUR);
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filters.addFilter("Bilateral Blur", FilterType.BILATERAL_BLUR);
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filters.addFilter("Curve Test Case", FilterType.SAMPLE_CURVE);
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AlertDialog.Builder builder = new AlertDialog.Builder(context);
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case BILATERAL_BLUR:
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return new GPUImageBilateralFilter();
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case SAMPLE_CURVE:
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return new GPUImageCurveFilter();
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default:
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throw new IllegalStateException("No filter of that type!");
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}
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BLEND_DISSOLVE, BLEND_EXCLUSION, BLEND_SOURCE_OVER, BLEND_HARD_LIGHT, BLEND_LIGHTEN, BLEND_ADD, BLEND_DIVIDE, BLEND_MULTIPLY, BLEND_OVERLAY, BLEND_SCREEN, BLEND_ALPHA,
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BLEND_COLOR, BLEND_HUE, BLEND_SATURATION, BLEND_LUMINOSITY, BLEND_LINEAR_BURN, BLEND_SOFT_LIGHT, BLEND_SUBTRACT, BLEND_CHROMA_KEY, BLEND_NORMAL, LOOKUP_AMATORKA,
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GAUSSIAN_BLUR, CROSSHATCH, BOX_BLUR, CGA_COLORSPACE, DILATION, KUWAHARA, RGB_DILATION, SKETCH, TOON, SMOOTH_TOON, BULGE_DISTORTION, GLASS_SPHERE, HAZE, LAPLACIAN, NON_MAXIMUM_SUPPRESSION,
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SPHERE_REFRACTION, SWIRL, WEAK_PIXEL_INCLUSION, FALSE_COLOR, COLOR_BALANCE, LEVELS_FILTER_MIN, BILATERAL_BLUR
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SPHERE_REFRACTION, SWIRL, WEAK_PIXEL_INCLUSION, FALSE_COLOR, COLOR_BALANCE, LEVELS_FILTER_MIN, BILATERAL_BLUR, SAMPLE_CURVE
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}
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private static class FilterList {
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adjuster = new LevelsMinMidAdjuster().filter(filter);
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} else if (filter instanceof GPUImageBilateralFilter) {
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adjuster = new BilateralAdjuster().filter(filter);
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} else if(filter instanceof GPUImageCurveFilter) {
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adjuster = new CurveAdjuster().filter(filter);
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}
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else {
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private class LevelsMinMidAdjuster extends Adjuster<GPUImageLevelsFilter> {
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@Override
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public void adjust(int percentage) {
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getFilter().setMin(0.0f, range(percentage, 0.0f, 1.0f) , 1.0f);
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getFilter().setMin(0.0f, range(percentage, 0.0f, 1.0f), 1.0f);
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}
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}
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}
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}
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private class CurveAdjuster extends Adjuster<GPUImageCurveFilter> {
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@Override
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public void adjust(final int percentage) {
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float value = range(percentage, 0.0f, 1.0f);
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getFilter().setCurveByPoints(new float[]{0.0f, 0.0f, 0.5f, value, 1.0f, 1.0f}, null, null);
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}
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}
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}
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}

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