src/be/nikiroo/utils/ImageText.java

   1 package be.nikiroo.utils;
   2
   3 import java.awt.Color;
   4 import java.awt.Dimension;
   5 import java.awt.Graphics;
   6 import java.awt.Image;
   7 import java.awt.image.BufferedImage;
   8 import java.awt.image.ImageObserver;
   9
  10 /**
  11  * This class converts an {@link Image} into a textual representation that can
  12  * be displayed to the user in a TUI.
  13  *
  14  * @author niki
  15  */
  16 public class ImageText {
  17         private Image image;
  18         private Dimension size;
  19         private String text;
  20         private boolean ready;
  21         private Mode mode;
  22         private boolean invert;
  23
  24         /**
  25          * Th rendering modes supported by this {@link ImageText} to convert
  26          * {@link Image}s into text.
  27          *
  28          * @author niki
  29          *
  30          */
  31         public enum Mode {
  32                 /**
  33                  * Use 5 different "colours" which are actually Unicode
  34                  * {@link Character}s representing
  35                  * <ul>
  36                  * <li>space (blank)</li>
  37                  * <li>low shade (░)</li>
  38                  * <li>medium shade (▒)</li>
  39                  * <li>high shade (▓)</li>
  40                  * <li>full block (█)</li>
  41                  * </ul>
  42                  */
  43                 DITHERING,
  44                 /**
  45                  * Use "block" Unicode {@link Character}s up to quarter blocks, thus in
  46                  * effect doubling the resolution both in vertical and horizontal space.
  47                  * Note that since 2 {@link Character}s next to each other are square,
  48                  * we will use 4 blocks per 2 blocks for w/h resolution.
  49                  */
  50                 DOUBLE_RESOLUTION,
  51                 /**
  52                  * Use {@link Character}s from both {@link Mode#DOUBLE_RESOLUTION} and
  53                  * {@link Mode#DITHERING}.
  54                  */
  55                 DOUBLE_DITHERING,
  56                 /**
  57                  * Only use ASCII {@link Character}s.
  58                  */
  59                 ASCII,
  60         }
  61
  62         /**
  63          * Create a new {@link ImageText} with the given parameters. Defaults to
  64          * {@link Mode#DOUBLE_DITHERING} and no colour inversion.
  65          *
  66          * @param image
  67          *            the source {@link Image}
  68          * @param size
  69          *            the final text size to target
  70          */
  71         public ImageText(Image image, Dimension size) {
  72                 this(image, size, Mode.DOUBLE_DITHERING, false);
  73         }
  74
  75         /**
  76          * Create a new {@link ImageText} with the given parameters.
  77          *
  78          * @param image
  79          *            the source {@link Image}
  80          * @param size
  81          *            the final text size to target
  82          * @param mode
  83          *            the mode of conversion
  84          * @param invert
  85          *            TRUE to invert colours rendering
  86          */
  87         public ImageText(Image image, Dimension size, Mode mode, boolean invert) {
  88                 setImage(image);
  89                 setSize(size);
  90                 setMode(mode);
  91                 setColorInvert(invert);
  92         }
  93
  94         /**
  95          * Change the source {@link Image}.
  96          *
  97          * @param image
  98          *            the new {@link Image}
  99          */
 100         public void setImage(Image image) {
 101                 this.text = null;
 102                 this.ready = false;
 103                 this.image = image;
 104         }
 105
 106         /**
 107          * Change the target size of this {@link ImageText}.
 108          *
 109          * @param size
 110          *            the new size
 111          */
 112         public void setSize(Dimension size) {
 113                 this.text = null;
 114                 this.ready = false;
 115                 this.size = size;
 116         }
 117
 118         /**
 119          * Change the image-to-text mode.
 120          *
 121          * @param mode
 122          *            the new {@link Mode}
 123          */
 124         public void setMode(Mode mode) {
 125                 this.mode = mode;
 126                 this.text = null;
 127                 this.ready = false;
 128         }
 129
 130         /**
 131          * Set the colour-invert mode.
 132          *
 133          * @param invert
 134          *            TRUE to inverse the colours
 135          */
 136         public void setColorInvert(boolean invert) {
 137                 this.invert = invert;
 138                 this.text = null;
 139                 this.ready = false;
 140         }
 141
 142         /**
 143          * Check if the colours are inverted.
 144          *
 145          * @return TRUE if the colours are inverted
 146          */
 147         public boolean isColorInvert() {
 148                 return invert;
 149         }
 150
 151         /**
 152          * Return the textual representation of the included {@link Image}.
 153          *
 154          * @return the {@link String} representation
 155          */
 156         public String getText() {
 157                 if (text == null) {
 158                         if (image == null || size == null || size.width == 0
 159                                         || size.height == 0)
 160                                 return "";
 161
 162                         int mult = 1;
 163                         if (mode == Mode.DOUBLE_RESOLUTION || mode == Mode.DOUBLE_DITHERING)
 164                                 mult = 2;
 165
 166                         int w = size.width * mult;
 167                         int h = size.height * mult;
 168
 169                         BufferedImage buff = new BufferedImage(w, h,
 170                                         BufferedImage.TYPE_INT_ARGB);
 171
 172                         Graphics gfx = buff.getGraphics();
 173
 174                         Dimension srcSize = getSize(image);
 175                         srcSize = new Dimension(srcSize.width * 2, srcSize.height);
 176                         int x = 0;
 177                         int y = 0;
 178
 179                         if (srcSize.width < srcSize.height) {
 180                                 double ratio = (double) size.width / (double) size.height;
 181                                 ratio *= (double) srcSize.height / (double) srcSize.width;
 182
 183                                 h = (int) Math.round(ratio * h);
 184                                 y = (buff.getHeight() - h) / 2;
 185                         } else {
 186                                 double ratio = (double) size.height / (double) size.width;
 187                                 ratio *= (double) srcSize.width / (double) srcSize.height;
 188
 189                                 w = (int) Math.round(ratio * w);
 190                                 x = (buff.getWidth() - w) / 2;
 191                         }
 192
 193                         if (gfx.drawImage(image, x, y, w, h, new ImageObserver() {
 194                                 public boolean imageUpdate(Image img, int infoflags, int x,
 195                                                 int y, int width, int height) {
 196                                         ImageText.this.ready = true;
 197                                         return true;
 198                                 }
 199                         })) {
 200                                 ready = true;
 201                         }
 202
 203                         while (!ready) {
 204                                 try {
 205                                         Thread.sleep(100);
 206                                 } catch (InterruptedException e) {
 207                                 }
 208                         }
 209
 210                         gfx.dispose();
 211
 212                         StringBuilder builder = new StringBuilder();
 213
 214                         for (int row = 0; row < buff.getHeight(); row += mult) {
 215                                 if (row > 0)
 216                                         builder.append('\n');
 217
 218                                 for (int col = 0; col < buff.getWidth(); col += mult) {
 219                                         if (mult == 1) {
 220                                                 char car = ' ';
 221                                                 float brightness = getBrightness(buff.getRGB(col, row));
 222                                                 if (mode == Mode.DITHERING)
 223                                                         car = getDitheringChar(brightness, " ░▒▓█");
 224                                                 if (mode == Mode.ASCII)
 225                                                         car = getDitheringChar(brightness, " .-+=o8#");
 226
 227                                                 builder.append(car);
 228                                         } else if (mult == 2) {
 229                                                 builder.append(getBlockChar( //
 230                                                                 buff.getRGB(col, row),//
 231                                                                 buff.getRGB(col + 1, row),//
 232                                                                 buff.getRGB(col, row + 1),//
 233                                                                 buff.getRGB(col + 1, row + 1),//
 234                                                                 mode == Mode.DOUBLE_DITHERING//
 235                                                 ));
 236                                         }
 237                                 }
 238                         }
 239
 240                         text = builder.toString();
 241                 }
 242
 243                 return text;
 244         }
 245
 246         @Override
 247         public String toString() {
 248                 return getText();
 249         }
 250
 251         /**
 252          * Return the size of the given {@link Image}.
 253          *
 254          * @param img
 255          *            the image to measure
 256          *
 257          * @return the size
 258          */
 259         static private Dimension getSize(Image img) {
 260                 Dimension size = null;
 261                 while (size == null) {
 262                         int w = img.getWidth(null);
 263                         int h = img.getHeight(null);
 264                         if (w > -1 && h > -1) {
 265                                 size = new Dimension(w, h);
 266                         } else {
 267                                 try {
 268                                         Thread.sleep(100);
 269                                 } catch (InterruptedException e) {
 270                                 }
 271                         }
 272                 }
 273
 274                 return size;
 275         }
 276
 277         /**
 278          * Return the {@link Character} corresponding to the given brightness level
 279          * from the evenly-separated given {@link Character}s.
 280          *
 281          * @param brightness
 282          *            the brightness level
 283          * @param cars
 284          *            the {@link Character}s to choose from, from less bright to
 285          *            most bright; <b>MUST</b> contain at least one
 286          *            {@link Character}
 287          *
 288          * @return the {@link Character} to use
 289          */
 290         private char getDitheringChar(float brightness, String cars) {
 291                 int index = Math.round(brightness * (cars.length() - 1));
 292                 return cars.charAt(index);
 293         }
 294
 295         /**
 296          * Return the {@link Character} corresponding to the 4 given colours in
 297          * {@link Mode#DOUBLE_RESOLUTION} or {@link Mode#DOUBLE_DITHERING} mode.
 298          *
 299          * @param upperleft
 300          *            the upper left colour
 301          * @param upperright
 302          *            the upper right colour
 303          * @param lowerleft
 304          *            the lower left colour
 305          * @param lowerright
 306          *            the lower right colour
 307          * @param dithering
 308          *            TRUE to use {@link Mode#DOUBLE_DITHERING}, FALSE for
 309          *            {@link Mode#DOUBLE_RESOLUTION}
 310          *
 311          * @return the {@link Character} to use
 312          */
 313         private char getBlockChar(int upperleft, int upperright, int lowerleft,
 314                         int lowerright, boolean dithering) {
 315                 int choice = 0;
 316                 if (getBrightness(upperleft) > 0.5f)
 317                         choice += 1;
 318                 if (getBrightness(upperright) > 0.5f)
 319                         choice += 2;
 320                 if (getBrightness(lowerleft) > 0.5f)
 321                         choice += 4;
 322                 if (getBrightness(lowerright) > 0.5f)
 323                         choice += 8;
 324
 325                 switch (choice) {
 326                 case 0:
 327                         return ' ';
 328                 case 1:
 329                         return '▘';
 330                 case 2:
 331                         return '▝';
 332                 case 3:
 333                         return '▀';
 334                 case 4:
 335                         return '▖';
 336                 case 5:
 337                         return '▌';
 338                 case 6:
 339                         return '▞';
 340                 case 7:
 341                         return '▛';
 342                 case 8:
 343                         return '▗';
 344                 case 9:
 345                         return '▚';
 346                 case 10:
 347                         return '▐';
 348                 case 11:
 349                         return '▜';
 350                 case 12:
 351                         return '▄';
 352                 case 13:
 353                         return '▙';
 354                 case 14:
 355                         return '▟';
 356                 case 15:
 357                         if (dithering) {
 358                                 float avg = 0;
 359                                 avg += getBrightness(upperleft);
 360                                 avg += getBrightness(upperright);
 361                                 avg += getBrightness(lowerleft);
 362                                 avg += getBrightness(lowerright);
 363                                 avg /= 4;
 364
 365                                 return getDitheringChar(avg, " ░▒▓█");
 366                         } else {
 367                                 return '█';
 368                         }
 369                 }
 370
 371                 return ' ';
 372         }
 373
 374         /**
 375          * Temporary array used so not to create a lot of new ones.
 376          */
 377         private float[] tmp = new float[4];
 378
 379         /**
 380          * Return the brightness value to use from the given ARGB colour.
 381          *
 382          * @param argb
 383          *            the argb colour
 384          *
 385          * @return the brightness to sue for computations
 386          */
 387         private float getBrightness(int argb) {
 388                 if (invert)
 389                         return 1 - rgb2hsb(argb, tmp)[2];
 390                 return rgb2hsb(argb, tmp)[2];
 391         }
 392
 393         /**
 394          * Convert the given ARGB colour in HSL/HSB, either into the supplied array
 395          * or into a new one if array is NULL.
 396          *
 397          * <p>
 398          * ARGB pixels are given in 0xAARRGGBB format, while the returned array will
 399          * contain Hue, Saturation, Lightness/Brightness, Alpha, in this order. H,
 400          * S, L and A are all ranging from 0 to 1 (indeed, H is in 1/360th).
 401          * </p>
 402          * pixel
 403          *
 404          * @param argb
 405          *            the ARGB colour pixel to convert
 406          * @param array
 407          *            the array to convert into or NULL to create a new one
 408          *
 409          * @return the array containing the HSL/HSB converted colour
 410          */
 411         static float[] rgb2hsb(int argb, float[] array) {
 412                 int a, r, g, b;
 413                 a = ((argb & 0xff000000) >> 24);
 414                 r = ((argb & 0x00ff0000) >> 16);
 415                 g = ((argb & 0x0000ff00) >> 8);
 416                 b = ((argb & 0x000000ff));
 417
 418                 if (array == null)
 419                         array = new float[4];
 420                 Color.RGBtoHSB(r, g, b, array);
 421
 422                 array[3] = a;
 423
 424                 return array;
 425
 426                 // // other implementation:
 427                 //
 428                 // float a, r, g, b;
 429                 // a = ((argb & 0xff000000) >> 24) / 255.0f;
 430                 // r = ((argb & 0x00ff0000) >> 16) / 255.0f;
 431                 // g = ((argb & 0x0000ff00) >> 8) / 255.0f;
 432                 // b = ((argb & 0x000000ff)) / 255.0f;
 433                 //
 434                 // float rgbMin, rgbMax;
 435                 // rgbMin = Math.min(r, Math.min(g, b));
 436                 // rgbMax = Math.max(r, Math.max(g, b));
 437                 //
 438                 // float l;
 439                 // l = (rgbMin + rgbMax) / 2;
 440                 //
 441                 // float s;
 442                 // if (rgbMin == rgbMax) {
 443                 // s = 0;
 444                 // } else {
 445                 // if (l <= 0.5) {
 446                 // s = (rgbMax - rgbMin) / (rgbMax + rgbMin);
 447                 // } else {
 448                 // s = (rgbMax - rgbMin) / (2.0f - rgbMax - rgbMin);
 449                 // }
 450                 // }
 451                 //
 452                 // float h;
 453                 // if (r > g && r > b) {
 454                 // h = (g - b) / (rgbMax - rgbMin);
 455                 // } else if (g > b) {
 456                 // h = 2.0f + (b - r) / (rgbMax - rgbMin);
 457                 // } else {
 458                 // h = 4.0f + (r - g) / (rgbMax - rgbMin);
 459                 // }
 460                 // h /= 6; // from 0 to 1
 461                 //
 462                 // return new float[] { h, s, l, a };
 463                 //
 464                 // // // natural mode:
 465                 // //
 466                 // // int aa = (int) Math.round(100 * a);
 467                 // // int hh = (int) (360 * h);
 468                 // // if (hh < 0)
 469                 // // hh += 360;
 470                 // // int ss = (int) Math.round(100 * s);
 471                 // // int ll = (int) Math.round(100 * l);
 472                 // //
 473                 // // return new int[] { hh, ss, ll, aa };
 474         }
 475 }