A-M baby

Task/Image-convolution/Java/image-convolution.java

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+import java.awt.image.*;
+import java.io.File;
+import java.io.IOException;
+import javax.imageio.*;
+
+public class ImageConvolution
+{
+  public static class ArrayData
+  {
+    public final int[] dataArray;
+    public final int width;
+    public final int height;
+
+    public ArrayData(int width, int height)
+    {
+      this(new int[width * height], width, height);
+    }
+
+    public ArrayData(int[] dataArray, int width, int height)
+    {
+      this.dataArray = dataArray;
+      this.width = width;
+      this.height = height;
+    }
+
+    public int get(int x, int y)
+    {  return dataArray[y * width + x];  }
+
+    public void set(int x, int y, int value)
+    {  dataArray[y * width + x] = value;  }
+  }
+
+  private static int bound(int value, int endIndex)
+  {
+    if (value < 0)
+      return 0;
+    if (value < endIndex)
+      return value;
+    return endIndex - 1;
+  }
+
+  public static ArrayData convolute(ArrayData inputData, ArrayData kernel, int kernelDivisor)
+  {
+    int inputWidth = inputData.width;
+    int inputHeight = inputData.height;
+    int kernelWidth = kernel.width;
+    int kernelHeight = kernel.height;
+    if ((kernelWidth <= 0) || ((kernelWidth & 1) != 1))
+      throw new IllegalArgumentException("Kernel must have odd width");
+    if ((kernelHeight <= 0) || ((kernelHeight & 1) != 1))
+      throw new IllegalArgumentException("Kernel must have odd height");
+    int kernelWidthRadius = kernelWidth >>> 1;
+    int kernelHeightRadius = kernelHeight >>> 1;
+
+    ArrayData outputData = new ArrayData(inputWidth, inputHeight);
+    for (int i = inputWidth - 1; i >= 0; i--)
+    {
+      for (int j = inputHeight - 1; j >= 0; j--)
+      {
+        double newValue = 0.0;
+        for (int kw = kernelWidth - 1; kw >= 0; kw--)
+          for (int kh = kernelHeight - 1; kh >= 0; kh--)
+            newValue += kernel.get(kw, kh) * inputData.get(
+                          bound(i + kw - kernelWidthRadius, inputWidth),
+                          bound(j + kh - kernelHeightRadius, inputHeight));
+        outputData.set(i, j, (int)Math.round(newValue / kernelDivisor));
+      }
+    }
+    return outputData;
+  }
+
+  public static ArrayData[] getArrayDatasFromImage(String filename) throws IOException
+  {
+    BufferedImage inputImage = ImageIO.read(new File(filename));
+    int width = inputImage.getWidth();
+    int height = inputImage.getHeight();
+    int[] rgbData = inputImage.getRGB(0, 0, width, height, null, 0, width);
+    ArrayData reds = new ArrayData(width, height);
+    ArrayData greens = new ArrayData(width, height);
+    ArrayData blues = new ArrayData(width, height);
+    for (int y = 0; y < height; y++)
+    {
+      for (int x = 0; x < width; x++)
+      {
+        int rgbValue = rgbData[y * width + x];
+        reds.set(x, y, (rgbValue >>> 16) & 0xFF);
+        greens.set(x, y, (rgbValue >>> 8) & 0xFF);
+        blues.set(x, y, rgbValue & 0xFF);
+      }
+    }
+    return new ArrayData[] { reds, greens, blues };
+  }
+
+  public static void writeOutputImage(String filename, ArrayData[] redGreenBlue) throws IOException
+  {
+    ArrayData reds = redGreenBlue[0];
+    ArrayData greens = redGreenBlue[1];
+    ArrayData blues = redGreenBlue[2];
+    BufferedImage outputImage = new BufferedImage(reds.width, reds.height,
+                                                  BufferedImage.TYPE_INT_ARGB);
+    for (int y = 0; y < reds.height; y++)
+    {
+      for (int x = 0; x < reds.width; x++)
+      {
+        int red = bound(reds.get(x, y), 256);
+        int green = bound(greens.get(x, y), 256);
+        int blue = bound(blues.get(x, y), 256);
+        outputImage.setRGB(x, y, (red << 16) | (green << 8) | blue | -0x01000000);
+      }
+    }
+    ImageIO.write(outputImage, "PNG", new File(filename));
+    return;
+  }
+
+  public static void main(String[] args) throws IOException
+  {
+    int kernelWidth = Integer.parseInt(args[2]);
+    int kernelHeight = Integer.parseInt(args[3]);
+    int kernelDivisor = Integer.parseInt(args[4]);
+    System.out.println("Kernel size: " + kernelWidth + "x" + kernelHeight +
+                       ", divisor=" + kernelDivisor);
+    int y = 5;
+    ArrayData kernel = new ArrayData(kernelWidth, kernelHeight);
+    for (int i = 0; i < kernelHeight; i++)
+    {
+      System.out.print("[");
+      for (int j = 0; j < kernelWidth; j++)
+      {
+        kernel.set(j, i, Integer.parseInt(args[y++]));
+        System.out.print(" " + kernel.get(j, i) + " ");
+      }
+      System.out.println("]");
+    }
+
+    ArrayData[] dataArrays = getArrayDatasFromImage(args[0]);
+    for (int i = 0; i < dataArrays.length; i++)
+      dataArrays[i] = convolute(dataArrays[i], kernel, kernelDivisor);
+    writeOutputImage(args[1], dataArrays);
+    return;
+  }
+}