View images on the command line

CLImager.java

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.RescaleOp;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.util.HashSet;
import java.util.Set;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;

import javax.imageio.ImageIO;
import javax.net.ssl.HttpsURLConnection;

/**
 * Much like the famous AAlib, this is intended to draw images on a console. However, instead of using pure black and white along with ascii characters,
 * this uses 2 unicode block characters to create different colors on a 16 color terminal. You must run this with the -Dfile.encoding=UTF-8 parameter!
 *
 * @author BananaPuncher714
 */
@SuppressWarnings("deprecation")
public final class CLImager {
	private static Set< Color > colors;
	private static Map< Color, String > charMap;
	private static final Color BLACK = new Color( 0, 0, 0 );
	private static final double[] color_multipliers = { 0.4375D, 0.1875D, 0.3125D, 0.0625D };

	public static void main( String[] args ) {
		String url = "http://www.rw-designer.com/icon-image/5547-64x64x32.png";
		if ( args.length > 0 ) {
			url = args[ 0 ];
		}
		int width = 200;
		if ( args.length > 1 ) {
			width = Math.max( 1, Integer.parseInt( args[ 1 ] ) );
		}

                if ( url.endsWith( ".ci" ) ) {
                	drawBashPicture( new File( System.getProperty( "user.dir" ) + "/" + url ) );
                } else {
			try {
                                if ( args.length > 2 ) {
				    drawBashPicture( saveToFile( resizeByWidth( getImage( url ), width ) ) );
                                } else {
                                    drawDirect( resizeByWidth( getImage( url ), width ) );
                                }
			} catch ( MalformedURLException e ) {
				e.printStackTrace();
			} catch ( IOException e ) {
				e.printStackTrace();
			}
                }
	}
	
        protected static void drawDirect( Image input ) {
        	BufferedImage image = toBufferedImage( input );
                dither( image );
                int width = image.getWidth();
                int height = image.getHeight();
                StringBuilder writer = new StringBuilder();
                for ( int y = 0; y < height; y++ ) {
                	StringBuilder builder = new StringBuilder();
                        for ( int x = 0; x < width; x++ ) {
                        	Color color = new Color( image.getRGB( x, y ) );
                                builder.append( charMap.get( color ) + "," );
                        }
                        String[] pixels = builder.toString().split( "," );
                        int pixInd = 1;
                        for ( String pixel : pixels ) {
                        	String[] parts = pixel.split( ":" );
                                String ch = "\u2588";
                                String fg = parts[ 1 ];
                                String fb = parts[ 2 ];
                                String bg = parts[ 3 ];
                                String bb = parts[ 4 ];

                                if ( parts[ 0 ].equalsIgnoreCase( "0" ) ) {
                   	             ch = "\u2591";
                                } else if ( parts[ 0 ].equalsIgnoreCase( "1" ) ) {
                                     ch = "\u2592";
                                }

                                if ( pixInd++ > 200 ) {
                                     break;
                                }
                                     writer.append( "\u001B[" + bb + ";4" + bg + "m\u001B[" + fb + ";3" + fg + "m" + ch );

                        }
                        writer.append( "\u001B[0m\n" );
                }
                System.out.println( writer.toString() );
        }


	public static void drawBashPicture( File file ) {
		try {
			FileReader fileReader = new FileReader(file);
			BufferedReader bufferedReader = new BufferedReader(fileReader);
			String line;
                        StringBuilder builder = new StringBuilder();
			while ( ( line = bufferedReader.readLine() ) != null ) {
				String[] pixels = line.split( "," );
				int pixInd = 1;
				for ( String pixel : pixels ) {
					String[] parts = pixel.split( ":" );
					String ch = "\u2588";
					String fg = parts[ 1 ];
					String fb = parts[ 2 ];
					String bg = parts[ 3 ];
					String bb = parts[ 4 ];
					
					if ( parts[ 0 ].equalsIgnoreCase( "0" ) ) {
						ch = "\u2591";
					} else if ( parts[ 0 ].equalsIgnoreCase( "1" ) ) {
						ch = "\u2592";
					}

					if ( pixInd++ > 200 ) {
						break;
					}
					
					builder.append( "\u001B[" + bb + ";4" + bg + "m\u001B[" + fb + ";3" + fg + "m" + ch );
					
				}
				builder.append( "\u001B[0m\n" );
			}
                        System.out.println( builder.toString() );
			fileReader.close();
		} catch ( Exception exception ) {
			exception.printStackTrace();
		}
	}

	public static File saveToFile( Image input ) {
		File output = new File( System.getProperty( "user.dir" ) + "/output.ci" );
		try {
			BufferedImage image = toBufferedImage( input );
			dither( image );
			int width = image.getWidth();
			int height = image.getHeight();
			PrintWriter writer = new PrintWriter( output, "UTF-8" );
			for ( int y = 0; y < height; y++ ) {
				StringBuilder builder = new StringBuilder();
				for ( int x = 0; x < width; x++ ) {
					Color color = new Color( image.getRGB( x, y ) );
					builder.append( charMap.get( color ) + "," );
				}
				writer.println( builder.toString() );
			}
			writer.close();
		} catch ( Exception exception ) {
			exception.printStackTrace();
		}
		return output;
	}

	static {
		colors = new HashSet< Color >();
		charMap = new HashMap< Color, String >();

		List< Color > cc = getNativeConsoleColors();

		for ( int c = 0; c < 2; c++ ) {
			double percent = 0;
			if ( c == 0 ) percent = .75;
			if ( c == 1 ) percent = .5;
			for ( int f = 0; f < cc.size(); f++ ) {
				for ( int b = 0; b < cc.size(); b++ ) {
					Color color = mixColors( cc.get( f ), cc.get( b ), percent );
					charMap.put( color, c + ":" + ( f % 8 ) + ":" + ( ( b > 7 ) ? "5" : "6" ) + ":" + ( b % 8 ) + ":" + ( ( f > 7 ) ? "1" : "0" ) );
					colors.add( color );
				}
			}
		}
//		System.out.println( "Collected " + colors.size() + " unique colors!" );
	}

	public static List< Color > getNativeConsoleColors() {
		List< Color > cc = new ArrayList< Color >();
		// Unbolded colors
		cc.add( new Color( 0, 0, 0 ) );
		cc.add( new Color( 170, 0, 0 ) );
		cc.add( new Color( 0, 170, 0 ) );
		cc.add( new Color( 170, 85, 0 ) );
		cc.add( new Color( 0, 0, 170 ) );
		cc.add( new Color( 170, 0, 170 ) );
		cc.add( new Color( 0, 170, 170 ) );
		cc.add( new Color( 170, 170, 170 ) );

		// Bolded colors
		cc.add( new Color( 85, 85, 85 ) );
		cc.add( new Color( 255, 85, 85 ) );
		cc.add( new Color( 85, 255, 85 ) );
		cc.add( new Color( 255, 255, 85 ) );
		cc.add( new Color( 85, 85, 255 ) );
		cc.add( new Color( 255, 85, 255 ) );
		cc.add( new Color( 85, 255, 255 ) );
		cc.add( new Color( 255, 255, 255 ) );

		return cc;
	}

	public static Color mixColors( Color c1, Color c2, double percent ) {
		double invP = 1 - percent;

		double r1 = c1.getRed() * invP;
		double g1 = c1.getGreen() * invP;
		double b1 = c1.getBlue() * invP;

		double r2 = c2.getRed() * percent;
		double g2 = c2.getGreen() * percent;
		double b2 = c2.getBlue() * percent;

		int r3 = ( int ) ( r1 + r2 ) / 2;
		int g3 = ( int ) ( g1 + g2 ) / 2;
		int b3 = ( int ) ( b1 + b2 ) / 2;

		return new Color( r3, g3, b3 );
	}

	public static Image resizeByWidth( Image input, int length ) {
		BufferedImage image = toBufferedImage( input );
		int width = image.getWidth();
		int height = image.getHeight();
		double scale = width / ( double ) length;

		return image.getScaledInstance( ( int ) ( width / scale ), ( int ) ( height / ( 2 * scale ) ), BufferedImage.SCALE_SMOOTH );
	}

	public static BufferedImage getImage( String url ) throws IOException, MalformedURLException {
		if ( !url.startsWith( "http" ) ) {
			try {
				return ImageIO.read( new File( url ) );
			} catch ( Exception exception ) {
				exception.printStackTrace();
			}
		}
		BufferedImage image = null;
		URLConnection connection = null;
		try {
			connection = new URL( url ).openConnection();
		} catch ( MalformedURLException exception ) {
			throw exception;
		}
		try {
			( ( HttpsURLConnection ) connection ).setInstanceFollowRedirects( true );
		} catch ( Exception exception ) {
			( ( HttpURLConnection ) connection ).setInstanceFollowRedirects( true );
		}
		connection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB;     rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13 (.NET CLR 3.5.30729)");

		image = ImageIO.read( connection.getInputStream() );
		return image;
	}

        public static BufferedImage shadeImage( double scale, Image img ) {
            RescaleOp op = new RescaleOp( ( float ) scale, 0, null );
            return op.filter( toBufferedImage( img ), null );
        }

	public static BufferedImage toBufferedImage( Image img ) {
		if (img instanceof BufferedImage) return ( BufferedImage ) img;

		BufferedImage bimage = new BufferedImage( img.getWidth(null), img.getHeight(null), BufferedImage.TYPE_INT_ARGB );

		Graphics2D bGr = bimage.createGraphics();
		bGr.drawImage(img, 0, 0, null);
		bGr.dispose();

		return bimage;
	}

	public static Color getBestMapColor( Color color ) {
		Color best_color = BLACK;
		double best_distance = -1.0D;
		for (Color check_color : colors) {
			double distance = getDistance(color, check_color);
			if ((distance < best_distance) || (best_distance == -1.0D)) {
				best_distance = distance;
				best_color = check_color;
			}
		}
		return best_color;
	}

	private static double getDistance(Color color_1, Color color_2) {
		double red_avg = (color_1.getRed() + color_2.getRed()) / 2.0D;
		double r = color_1.getRed() - color_2.getRed();
		double g = color_1.getGreen() - color_2.getGreen();
		int b = color_1.getBlue() - color_2.getBlue();
		double weight_red = 2.0D + red_avg / 256.0D;
		double weight_green = 4.0D;
		double weight_blue = 2.0D + (255.0D - red_avg) / 256.0D;
		return weight_red * r * r + weight_green * g * g + weight_blue * b * b;
	}

	public static void dither(BufferedImage image) {
		int width = image.getWidth();
		int height = image.getHeight();
		int[][] dither_buffer = new int[2][Math.max(width, height) * 3];

		int[] y_temps = { 0, 1, 1, 1 };
		for (int x = 0; x < width; x++) {
			dither_buffer[0] = dither_buffer[1];
			dither_buffer[1] = new int[Math.max(width, height) * 3];
			for (int y = 0; y < height; y++) {
				int rgb = image.getRGB(x, y);
				Color color = new Color(rgb);
				if (color.getAlpha() != 0) {
					int red = color.getRed();
					int green = color.getGreen();
					int blue = color.getBlue();
					red = Math.max(0, Math.min(red + dither_buffer[0][(y * 3)], 255));
					green = Math.max(0, Math.min(green + dither_buffer[0][(y * 3 + 1)], 255));
					blue = Math.max(0, Math.min(blue + dither_buffer[0][(y * 3 + 2)], 255));
					Color matched_color = getBestMapColor(new Color(red, green, blue));
					int delta_r = red - matched_color.getRed();
					int delta_g = green - matched_color.getGreen();
					int delta_b = blue - matched_color.getBlue();
					int[] x_temps = { y + 1, y - 1, y, y + 1 };
					for (int i = 0; i < x_temps.length; i++) {
						int temp_y = y_temps[i];
						int temp_x = x_temps[i];
						if ((temp_y < height) && (temp_x < width) && (temp_x > 0)) {
							dither_buffer[temp_y][(temp_x * 3)] = ((int)(dither_buffer[temp_y][(temp_x * 3)] + color_multipliers[i] * delta_r));

							dither_buffer[temp_y][(temp_x * 3 + 1)] = ((int)(dither_buffer[temp_y][(temp_x * 3 + 1)] + color_multipliers[i] * delta_g));

							dither_buffer[temp_y][(temp_x * 3 + 2)] = ((int)(dither_buffer[temp_y][(temp_x * 3 + 2)] + color_multipliers[i] * delta_b));
						}
					}
					image.setRGB(x, y, matched_color.getRGB());
				} else {
					image.setRGB(x, y, 0);
				}
			}
		}
	}
}