add java converter for turning an image intto ascii representation

src/java/toascii/images/ImageToAscii.java

@@ -0,0 +1,59 @@
+package toascii.images;
+
+import java.awt.image.BufferedImage;
+
+public class ImageToAscii {
+	static final char[] asciiChars = {'#', 'A', '@', '%', '$', '+', '=', '*', ':', ',', '.', ' '};
+	static final int spanLength = "<span style=\"color:rgb(255,255,255);\">X</span>".length();
+	static final int lineTerminatorLength = "<br>".length();
+
+	public static String convert(BufferedImage image, boolean useColor) {
+		int width = image.getWidth();
+		int height = image.getHeight();
+
+		int maxLength = (useColor ?
+		                 (width * height * spanLength) + (height * lineTerminatorLength) :
+		                 (width * height) + height);
+
+		StringBuilder sb = new StringBuilder(maxLength);
+
+		int[] pixels = image.getRGB(0, 0, width, height, null, 0, width);
+		for (int y = 0; y < height; ++y) {
+			for (int x = 0; x < width; ++x) {
+				int argb = pixels[(y * width) + x];
+				int r = (0x00ff0000 & argb) >> 16;
+				int g = (0x0000ff00 & argb) >> 8;
+				int b = (0x000000ff & argb);
+				int brightness = (int)Math.sqrt((r * r * 0.241f) +
+				                                (g * g * 0.691f) +
+				                                (b * b * 0.068f));
+				int charIndex;
+				if (brightness == 0.0f)
+					charIndex = asciiChars.length - 1;
+				else
+					charIndex = (int)((brightness / 255.0f) * asciiChars.length) - 1;
+
+				char pixelChar = asciiChars[charIndex > 0 ? charIndex : 0];
+
+				if (useColor) {
+					sb.append("<span style=\"color:rgb(");
+					sb.append(r);
+					sb.append(',');
+					sb.append(g);
+					sb.append(',');
+					sb.append(b);
+					sb.append(");\">");
+					sb.append(pixelChar);
+					sb.append("</span>");
+				} else
+					sb.append(pixelChar);
+			}
+			if (useColor)
+				sb.append("<br>");
+			else
+				sb.append('\n');
+		}
+
+		return sb.toString();
+	}
+}