// "math" is the fastest// "bitwise" is 2x slower than "math"// "if" is 3x slower than "math"
public class FiltersBenchmark{ public static final int METHOD_IF = 0; public static final int METHOD_MATH = 1; public static final int METHOD_BITWISE = 2;
public static final String[] methodNames = new String[] { "if", "math", "bitwise" };
public static void main(String[] args) { int method = METHOD_BITWISE;
int iterations = 1000; int width = 640; int height = 480; byte[] input = new byte[width * height]; byte[] output = new byte[width * height];
int x = 0; for (int i = 0; i < input.length; i++) { x += 1337; x = ((x >> 16) ^ x) * 0x45d9f3b; x = ((x >> 16) ^ x) * 0x45d9f3b; x = (x >> 16) ^ x; input[i] = (byte)(x & 7); }
long startTime = System.nanoTime();
switch (method) { case METHOD_IF: for (int i = 0; i < iterations; i++) filterMinIf(output, input, width, height); break; case METHOD_MATH: for (int i = 0; i < iterations; i++) filterMinMath(output, input, width, height); break; case METHOD_BITWISE: for (int i = 0; i < iterations; i++) filterMinBitwise(output, input, width, height); break; }
long endTime = System.nanoTime();
System.out.println( FiltersBenchmark.class.getSimpleName() + "\n" + "Method: " + methodNames[method] + "\n" + "Area: " + width + "x" + height + "\n" + "Iterations: " + iterations + "\n" + "Time: " + (double)(endTime - startTime) / 1E6 + "ms" ); }
public static void filterMinIf(byte[] outputPixels, byte[] inputPixels, int width, int height) { if (width == 1) { filterEdgeMinIf(outputPixels, inputPixels, width, height, height, 0, 0, 0, 1); return; }
int p1, p2, p3, p4, p5, p6, p7, p8, p9; int min = 0;
for (int y = 1; y < height-1; y++) { int offset = 1 + width * y; p2 = inputPixels[offset-width-1] & 0xff; p3 = inputPixels[offset-width] & 0xff; p5 = inputPixels[offset-1] & 0xff; p6 = inputPixels[offset] & 0xff; p8 = inputPixels[offset+width-1] & 0xff; p9 = inputPixels[offset+width] & 0xff;
for (int x = 0; x < width-2; x++) { p1 = p2; p2 = p3; p3 = inputPixels[offset-width+x+1] & 0xff; p4 = p5; p5 = p6; p6 = inputPixels[offset+x+1] & 0xff; p7 = p8; p8 = p9; p9 = inputPixels[offset+width+x+1] & 0xff;
min = p5; if (p1<min) min = p1; if (p2<min) min = p2; if (p3<min) min = p3; if (p4<min) min = p4; if (p6<min) min = p6; if (p7<min) min = p7; if (p8<min) min = p8; if (p9<min) min = p9;
outputPixels[offset+x] = (byte)min; } }
filterEdgeMinIf(outputPixels, inputPixels, width, height, height, 0, 0, 0, 1); filterEdgeMinIf(outputPixels, inputPixels, width, height, width, 0, 0, 1, 0); filterEdgeMinIf(outputPixels, inputPixels, width, height, height, width-1, 0, 0, 1); filterEdgeMinIf(outputPixels, inputPixels, width, height, width, 0, height-1, 1, 0); }
public static void filterEdgeMinIf(byte[] outputPixels, byte[] inputPixels, int width, int height, int n, int x, int y, int xinc, int yinc) { int p1, p2, p3, p4, p5, p6, p7, p8, p9; int min = 0; int count;
for (int i=0; i<n; i++) { int left = x > 0 ? x-1 : 0; int right = x < width-1 ? x+1 : width-1; int top = y > 0 ? y-1 : 0; int bottom = y < height-1 ? y+1 : height-1;
p1 = inputPixels[left + width * top] & 0xff; p2 = inputPixels[x + width * top] & 0xff; p3 = inputPixels[right + width * top] & 0xff; p4 = inputPixels[left + width * y] & 0xff; p5 = inputPixels[x + width * y] & 0xff; p6 = inputPixels[right + width * y] & 0xff; p7 = inputPixels[left + width * bottom] & 0xff; p8 = inputPixels[x + width * bottom] & 0xff; p9 = inputPixels[right + width * bottom] & 0xff;
min = p5; if (p1<min) min = p1; if (p2<min) min = p2; if (p3<min) min = p3; if (p4<min) min = p4; if (p6<min) min = p6; if (p7<min) min = p7; if (p8<min) min = p8; if (p9<min) min = p9;
outputPixels[x+y*width] = (byte)min; x += xinc; y += yinc; } }
public static void filterMinMath(byte[] outputPixels, byte[] inputPixels, int width, int height) { if (width == 1) { filterEdgeMinMath(outputPixels, inputPixels, width, height, height, 0, 0, 0, 1); return; }
int p1, p2, p3, p4, p5, p6, p7, p8, p9; int min = 0;
for (int y = 1; y < height-1; y++) { int offset = 1 + width * y; p2 = inputPixels[offset-width-1] & 0xff; p3 = inputPixels[offset-width] & 0xff; p5 = inputPixels[offset-1] & 0xff; p6 = inputPixels[offset] & 0xff; p8 = inputPixels[offset+width-1] & 0xff; p9 = inputPixels[offset+width] & 0xff;
for (int x = 0; x < width-2; x++) { p1 = p2; p2 = p3; p3 = inputPixels[offset-width+x+1] & 0xff; p4 = p5; p5 = p6; p6 = inputPixels[offset+x+1] & 0xff; p7 = p8; p8 = p9; p9 = inputPixels[offset+width+x+1] & 0xff;
min = p5; min = Math.min(min, p1); min = Math.min(min, p2); min = Math.min(min, p3); min = Math.min(min, p4); min = Math.min(min, p6); min = Math.min(min, p7); min = Math.min(min, p8); min = Math.min(min, p9);
outputPixels[offset+x] = (byte)min; } }
filterEdgeMinMath(outputPixels, inputPixels, width, height, height, 0, 0, 0, 1); filterEdgeMinMath(outputPixels, inputPixels, width, height, width, 0, 0, 1, 0); filterEdgeMinMath(outputPixels, inputPixels, width, height, height, width-1, 0, 0, 1); filterEdgeMinMath(outputPixels, inputPixels, width, height, width, 0, height-1, 1, 0); }
public static void filterEdgeMinMath(byte[] outputPixels, byte[] inputPixels, int width, int height, int n, int x, int y, int xinc, int yinc) { int p1, p2, p3, p4, p5, p6, p7, p8, p9; int min = 0; int count;
for (int i=0; i<n; i++) { int left = x > 0 ? x-1 : 0; int right = x < width-1 ? x+1 : width-1; int top = y > 0 ? y-1 : 0; int bottom = y < height-1 ? y+1 : height-1;
p1 = inputPixels[left + width * top] & 0xff; p2 = inputPixels[x + width * top] & 0xff; p3 = inputPixels[right + width * top] & 0xff; p4 = inputPixels[left + width * y] & 0xff; p5 = inputPixels[x + width * y] & 0xff; p6 = inputPixels[right + width * y] & 0xff; p7 = inputPixels[left + width * bottom] & 0xff; p8 = inputPixels[x + width * bottom] & 0xff; p9 = inputPixels[right + width * bottom] & 0xff;
min = p5; min = Math.min(min, p1); min = Math.min(min, p2); min = Math.min(min, p3); min = Math.min(min, p4); min = Math.min(min, p6); min = Math.min(min, p7); min = Math.min(min, p8); min = Math.min(min, p9);
outputPixels[x+y*width] = (byte)min; x += xinc; y += yinc; } }
public static void filterMinBitwise(byte[] outputPixels, byte[] inputPixels, int width, int height) { if (width == 1) { filterEdgeMinBitwise(outputPixels, inputPixels, width, height, height, 0, 0, 0, 1); return; }
int p1, p2, p3, p4, p5, p6, p7, p8, p9; int min = 0;
for (int y = 1; y < height-1; y++) { int offset = 1 + width * y; p2 = inputPixels[offset-width-1] & 0xff; p3 = inputPixels[offset-width] & 0xff; p5 = inputPixels[offset-1] & 0xff; p6 = inputPixels[offset] & 0xff; p8 = inputPixels[offset+width-1] & 0xff; p9 = inputPixels[offset+width] & 0xff;
for (int x = 0; x < width-2; x++) { p1 = p2; p2 = p3; p3 = inputPixels[offset-width+x+1] & 0xff; p4 = p5; p5 = p6; p6 = inputPixels[offset+x+1] & 0xff; p7 = p8; p8 = p9; p9 = inputPixels[offset+width+x+1] & 0xff;
min = p5; min = (((p1-min) >> 31) & p1) | (~((p1-min) >> 31) & min); min = (((p2-min) >> 31) & p2) | (~((p2-min) >> 31) & min); min = (((p3-min) >> 31) & p3) | (~((p3-min) >> 31) & min); min = (((p4-min) >> 31) & p4) | (~((p4-min) >> 31) & min); min = (((p6-min) >> 31) & p6) | (~((p6-min) >> 31) & min); min = (((p7-min) >> 31) & p7) | (~((p7-min) >> 31) & min); min = (((p8-min) >> 31) & p8) | (~((p8-min) >> 31) & min); min = (((p9-min) >> 31) & p9) | (~((p9-min) >> 31) & min);
outputPixels[offset+x] = (byte)min; } }
filterEdgeMinBitwise(outputPixels, inputPixels, width, height, height, 0, 0, 0, 1); filterEdgeMinBitwise(outputPixels, inputPixels, width, height, width, 0, 0, 1, 0); filterEdgeMinBitwise(outputPixels, inputPixels, width, height, height, width-1, 0, 0, 1); filterEdgeMinBitwise(outputPixels, inputPixels, width, height, width, 0, height-1, 1, 0); }
public static void filterEdgeMinBitwise(byte[] outputPixels, byte[] inputPixels, int width, int height, int n, int x, int y, int xinc, int yinc) { int p1, p2, p3, p4, p5, p6, p7, p8, p9; int min = 0; int count;
for (int i=0; i<n; i++) { int left = x > 0 ? x-1 : 0; int right = x < width-1 ? x+1 : width-1; int top = y > 0 ? y-1 : 0; int bottom = y < height-1 ? y+1 : height-1;
p1 = inputPixels[left + width * top] & 0xff; p2 = inputPixels[x + width * top] & 0xff; p3 = inputPixels[right + width * top] & 0xff; p4 = inputPixels[left + width * y] & 0xff; p5 = inputPixels[x + width * y] & 0xff; p6 = inputPixels[right + width * y] & 0xff; p7 = inputPixels[left + width * bottom] & 0xff; p8 = inputPixels[x + width * bottom] & 0xff; p9 = inputPixels[right + width * bottom] & 0xff;
min = p5; min = (((p1-min) >> 31) & p1) | (~((p1-min) >> 31) & min); min = (((p2-min) >> 31) & p2) | (~((p2-min) >> 31) & min); min = (((p3-min) >> 31) & p3) | (~((p3-min) >> 31) & min); min = (((p4-min) >> 31) & p4) | (~((p4-min) >> 31) & min); min = (((p6-min) >> 31) & p6) | (~((p6-min) >> 31) & min); min = (((p7-min) >> 31) & p7) | (~((p7-min) >> 31) & min); min = (((p8-min) >> 31) & p8) | (~((p8-min) >> 31) & min); min = (((p9-min) >> 31) & p9) | (~((p9-min) >> 31) & min);
outputPixels[x+y*width] = (byte)min; x += xinc; y += yinc; } }}
