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25  
26  
27  package java.awt.image;
28  
29  import java.awt.color.ColorSpace;
30  import java.awt.geom.Rectangle2D;
31  import java.awt.Rectangle;
32  import java.awt.RenderingHints;
33  import java.awt.geom.Point2D;
34  import sun.awt.image.ImagingLib;
35  
36  /**
37   * This class implements a lookup operation from the source
38   * to the destination.  The LookupTable object may contain a single array
39   * or multiple arrays, subject to the restrictions below.
40   * <p>
41   * For Rasters, the lookup operates on bands.  The number of
42   * lookup arrays may be one, in which case the same array is
43   * applied to all bands, or it must equal the number of Source
44   * Raster bands.
45   * <p>
46   * For BufferedImages, the lookup operates on color and alpha components.
47   * The number of lookup arrays may be one, in which case the
48   * same array is applied to all color (but not alpha) components.
49   * Otherwise, the number of lookup arrays may
50   * equal the number of Source color components, in which case no
51   * lookup of the alpha component (if present) is performed.
52   * If neither of these cases apply, the number of lookup arrays
53   * must equal the number of Source color components plus alpha components,
54   * in which case lookup is performed for all color and alpha components.
55   * This allows non-uniform rescaling of multi-band BufferedImages.
56   * <p>
57   * BufferedImage sources with premultiplied alpha data are treated in the same
58   * manner as non-premultiplied images for purposes of the lookup.  That is,
59   * the lookup is done per band on the raw data of the BufferedImage source
60   * without regard to whether the data is premultiplied.  If a color conversion
61   * is required to the destination ColorModel, the premultiplied state of
62   * both source and destination will be taken into account for this step.
63   * <p>
64   * Images with an IndexColorModel cannot be used.
65   * <p>
66   * If a RenderingHints object is specified in the constructor, the
67   * color rendering hint and the dithering hint may be used when color
68   * conversion is required.
69   * <p>
70   * This class allows the Source to be the same as the Destination.
71   *
72   * @see LookupTable
73   * @see java.awt.RenderingHints#KEY_COLOR_RENDERING
74   * @see java.awt.RenderingHints#KEY_DITHERING
75   */
76  
77  public class LookupOp implements BufferedImageOp, RasterOp {
78      private LookupTable ltable;
79      private int numComponents;
80      RenderingHints hints;
81  
82      /**
83       * Constructs a <code>LookupOp</code> object given the lookup
84       * table and a <code>RenderingHints</code> object, which might
85       * be <code>null</code>.
86       * @param lookup the specified <code>LookupTable</code>
87       * @param hints the specified <code>RenderingHints</code>,
88       *        or <code>null</code>
89       */
90      public LookupOp(LookupTable lookup, RenderingHints hints) {
91          this.ltable = lookup;
92          this.hints  = hints;
93          numComponents = ltable.getNumComponents();
94      }
95  
96      /**
97       * Returns the <code>LookupTable</code>.
98       * @return the <code>LookupTable</code> of this
99       *         <code>LookupOp</code>.
100      */
101     public final LookupTable getTable() {
102         return ltable;
103     }
104 
105     /**
106      * Performs a lookup operation on a <code>BufferedImage</code>.
107      * If the color model in the source image is not the same as that
108      * in the destination image, the pixels will be converted
109      * in the destination.  If the destination image is <code>null</code>,
110      * a <code>BufferedImage</code> will be created with an appropriate
111      * <code>ColorModel</code>.  An <code>IllegalArgumentException</code>
112      * might be thrown if the number of arrays in the
113      * <code>LookupTable</code> does not meet the restrictions
114      * stated in the class comment above, or if the source image
115      * has an <code>IndexColorModel</code>.
116      * @param src the <code>BufferedImage</code> to be filtered
117      * @param dst the <code>BufferedImage</code> in which to
118      *            store the results of the filter operation
119      * @return the filtered <code>BufferedImage</code>.
120      * @throws IllegalArgumentException if the number of arrays in the
121      *         <code>LookupTable</code> does not meet the restrictions
122      *         described in the class comments, or if the source image
123      *         has an <code>IndexColorModel</code>.
124      */
125     public final BufferedImage filter(BufferedImage src, BufferedImage dst) {
126         ColorModel srcCM = src.getColorModel();
127         int numBands = srcCM.getNumColorComponents();
128         ColorModel dstCM;
129         if (srcCM instanceof IndexColorModel) {
130             throw new
131                 IllegalArgumentException("LookupOp cannot be "+
132                                          "performed on an indexed image");
133         }
134         int numComponents = ltable.getNumComponents();
135         if (numComponents != 1 &&
136             numComponents != srcCM.getNumComponents() &&
137             numComponents != srcCM.getNumColorComponents())
138         {
139             throw new IllegalArgumentException("Number of arrays in the "+
140                                                " lookup table ("+
141                                                numComponents+
142                                                " is not compatible with the "+
143                                                " src image: "+src);
144         }
145 
146 
147         boolean needToConvert = false;
148 
149         int width = src.getWidth();
150         int height = src.getHeight();
151 
152         if (dst == null) {
153             dst = createCompatibleDestImage(src, null);
154             dstCM = srcCM;
155         }
156         else {
157             if (width != dst.getWidth()) {
158                 throw new
159                     IllegalArgumentException("Src width ("+width+
160                                              ") not equal to dst width ("+
161                                              dst.getWidth()+")");
162             }
163             if (height != dst.getHeight()) {
164                 throw new
165                     IllegalArgumentException("Src height ("+height+
166                                              ") not equal to dst height ("+
167                                              dst.getHeight()+")");
168             }
169 
170             dstCM = dst.getColorModel();
171             if (srcCM.getColorSpace().getType() !=
172                 dstCM.getColorSpace().getType())
173             {
174                 needToConvert = true;
175                 dst = createCompatibleDestImage(src, null);
176             }
177 
178         }
179 
180         BufferedImage origDst = dst;
181 
182         if (ImagingLib.filter(this, src, dst) == null) {
183             // Do it the slow way
184             WritableRaster srcRaster = src.getRaster();
185             WritableRaster dstRaster = dst.getRaster();
186 
187             if (srcCM.hasAlpha()) {
188                 if (numBands-1 == numComponents || numComponents == 1) {
189                     int minx = srcRaster.getMinX();
190                     int miny = srcRaster.getMinY();
191                     int[] bands = new int[numBands-1];
192                     for (int i=0; i < numBands-1; i++) {
193                         bands[i] = i;
194                     }
195                     srcRaster =
196                         srcRaster.createWritableChild(minx, miny,
197                                                       srcRaster.getWidth(),
198                                                       srcRaster.getHeight(),
199                                                       minx, miny,
200                                                       bands);
201                 }
202             }
203             if (dstCM.hasAlpha()) {
204                 int dstNumBands = dstRaster.getNumBands();
205                 if (dstNumBands-1 == numComponents || numComponents == 1) {
206                     int minx = dstRaster.getMinX();
207                     int miny = dstRaster.getMinY();
208                     int[] bands = new int[numBands-1];
209                     for (int i=0; i < numBands-1; i++) {
210                         bands[i] = i;
211                     }
212                     dstRaster =
213                         dstRaster.createWritableChild(minx, miny,
214                                                       dstRaster.getWidth(),
215                                                       dstRaster.getHeight(),
216                                                       minx, miny,
217                                                       bands);
218                 }
219             }
220 
221             filter(srcRaster, dstRaster);
222         }
223 
224         if (needToConvert) {
225             // ColorModels are not the same
226             ColorConvertOp ccop = new ColorConvertOp(hints);
227             ccop.filter(dst, origDst);
228         }
229 
230         return origDst;
231     }
232 
233     /**
234      * Performs a lookup operation on a <code>Raster</code>.
235      * If the destination <code>Raster</code> is <code>null</code>,
236      * a new <code>Raster</code> will be created.
237      * The <code>IllegalArgumentException</code> might be thrown
238      * if the source <code>Raster</code> and the destination
239      * <code>Raster</code> do not have the same
240      * number of bands or if the number of arrays in the
241      * <code>LookupTable</code> does not meet the
242      * restrictions stated in the class comment above.
243      * @param src the source <code>Raster</code> to filter
244      * @param dst the destination <code>WritableRaster</code> for the
245      *            filtered <code>src</code>
246      * @return the filtered <code>WritableRaster</code>.
247      * @throws IllegalArgumentException if the source and destinations
248      *         rasters do not have the same number of bands, or the
249      *         number of arrays in the <code>LookupTable</code> does
250      *         not meet the restrictions described in the class comments.
251      *
252      */
253     public final WritableRaster filter (Raster src, WritableRaster dst) {
254         int numBands  = src.getNumBands();
255         int dstLength = dst.getNumBands();
256         int height    = src.getHeight();
257         int width     = src.getWidth();
258         int srcPix[]  = new int[numBands];
259 
260         // Create a new destination Raster, if needed
261 
262         if (dst == null) {
263             dst = createCompatibleDestRaster(src);
264         }
265         else if (height != dst.getHeight() || width != dst.getWidth()) {
266             throw new
267                 IllegalArgumentException ("Width or height of Rasters do not "+
268                                           "match");
269         }
270         dstLength = dst.getNumBands();
271 
272         if (numBands != dstLength) {
273             throw new
274                 IllegalArgumentException ("Number of channels in the src ("
275                                           + numBands +
276                                           ") does not match number of channels"
277                                           + " in the destination ("
278                                           + dstLength + ")");
279         }
280         int numComponents = ltable.getNumComponents();
281         if (numComponents != 1 && numComponents != src.getNumBands()) {
282             throw new IllegalArgumentException("Number of arrays in the "+
283                                                " lookup table ("+
284                                                numComponents+
285                                                " is not compatible with the "+
286                                                " src Raster: "+src);
287         }
288 
289 
290         if (ImagingLib.filter(this, src, dst) != null) {
291             return dst;
292         }
293 
294         // Optimize for cases we know about
295         if (ltable instanceof ByteLookupTable) {
296             byteFilter ((ByteLookupTable) ltable, src, dst,
297                         width, height, numBands);
298         }
299         else if (ltable instanceof ShortLookupTable) {
300             shortFilter ((ShortLookupTable) ltable, src, dst, width,
301                          height, numBands);
302         }
303         else {
304             // Not one we recognize so do it slowly
305             int sminX = src.getMinX();
306             int sY = src.getMinY();
307             int dminX = dst.getMinX();
308             int dY = dst.getMinY();
309             for (int y=0; y < height; y++, sY++, dY++) {
310                 int sX = sminX;
311                 int dX = dminX;
312                 for (int x=0; x < width; x++, sX++, dX++) {
313                     // Find data for all bands at this x,y position
314                     src.getPixel(sX, sY, srcPix);
315 
316                     // Lookup the data for all bands at this x,y position
317                     ltable.lookupPixel(srcPix, srcPix);
318 
319                     // Put it back for all bands
320                     dst.setPixel(dX, dY, srcPix);
321                 }
322             }
323         }
324 
325         return dst;
326     }
327 
328     /**
329      * Returns the bounding box of the filtered destination image.  Since
330      * this is not a geometric operation, the bounding box does not
331      * change.
332      * @param src the <code>BufferedImage</code> to be filtered
333      * @return the bounds of the filtered definition image.
334      */
335     public final Rectangle2D getBounds2D (BufferedImage src) {
336         return getBounds2D(src.getRaster());
337     }
338 
339     /**
340      * Returns the bounding box of the filtered destination Raster.  Since
341      * this is not a geometric operation, the bounding box does not
342      * change.
343      * @param src the <code>Raster</code> to be filtered
344      * @return the bounds of the filtered definition <code>Raster</code>.
345      */
346     public final Rectangle2D getBounds2D (Raster src) {
347         return src.getBounds();
348 
349     }
350 
351     /**
352      * Creates a zeroed destination image with the correct size and number of
353      * bands.  If destCM is <code>null</code>, an appropriate
354      * <code>ColorModel</code> will be used.
355      * @param src       Source image for the filter operation.
356      * @param destCM    the destination's <code>ColorModel</code>, which
357      *                  can be <code>null</code>.
358      * @return a filtered destination <code>BufferedImage</code>.
359      */
360     public BufferedImage createCompatibleDestImage (BufferedImage src,
361                                                     ColorModel destCM) {
362         BufferedImage image;
363         int w = src.getWidth();
364         int h = src.getHeight();
365         int transferType = DataBuffer.TYPE_BYTE;
366         if (destCM == null) {
367             ColorModel cm = src.getColorModel();
368             Raster raster = src.getRaster();
369             if (cm instanceof ComponentColorModel) {
370                 DataBuffer db = raster.getDataBuffer();
371                 boolean hasAlpha = cm.hasAlpha();
372                 boolean isPre    = cm.isAlphaPremultiplied();
373                 int trans        = cm.getTransparency();
374                 int[] nbits = null;
375                 if (ltable instanceof ByteLookupTable) {
376                     if (db.getDataType() == db.TYPE_USHORT) {
377                         // Dst raster should be of type byte
378                         if (hasAlpha) {
379                             nbits = new int[2];
380                             if (trans == cm.BITMASK) {
381                                 nbits[1] = 1;
382                             }
383                             else {
384                                 nbits[1] = 8;
385                             }
386                         }
387                         else {
388                             nbits = new int[1];
389                         }
390                         nbits[0] = 8;
391                     }
392                     // For byte, no need to change the cm
393                 }
394                 else if (ltable instanceof ShortLookupTable) {
395                     transferType = DataBuffer.TYPE_USHORT;
396                     if (db.getDataType() == db.TYPE_BYTE) {
397                         if (hasAlpha) {
398                             nbits = new int[2];
399                             if (trans == cm.BITMASK) {
400                                 nbits[1] = 1;
401                             }
402                             else {
403                                 nbits[1] = 16;
404                             }
405                         }
406                         else {
407                             nbits = new int[1];
408                         }
409                         nbits[0] = 16;
410                     }
411                 }
412                 if (nbits != null) {
413                     cm = new ComponentColorModel(cm.getColorSpace(),
414                                                  nbits, hasAlpha, isPre,
415                                                  trans, transferType);
416                 }
417             }
418             image = new BufferedImage(cm,
419                                       cm.createCompatibleWritableRaster(w, h),
420                                       cm.isAlphaPremultiplied(),
421                                       null);
422         }
423         else {
424             image = new BufferedImage(destCM,
425                                       destCM.createCompatibleWritableRaster(w,
426                                                                             h),
427                                       destCM.isAlphaPremultiplied(),
428                                       null);
429         }
430 
431         return image;
432     }
433 
434     /**
435      * Creates a zeroed-destination <code>Raster</code> with the
436      * correct size and number of bands, given this source.
437      * @param src the <code>Raster</code> to be transformed
438      * @return the zeroed-destination <code>Raster</code>.
439      */
440     public WritableRaster createCompatibleDestRaster (Raster src) {
441         return src.createCompatibleWritableRaster();
442     }
443 
444     /**
445      * Returns the location of the destination point given a
446      * point in the source.  If <code>dstPt</code> is not
447      * <code>null</code>, it will be used to hold the return value.
448      * Since this is not a geometric operation, the <code>srcPt</code>
449      * will equal the <code>dstPt</code>.
450      * @param srcPt a <code>Point2D</code> that represents a point
451      *        in the source image
452      * @param dstPt a <code>Point2D</code>that represents the location
453      *        in the destination
454      * @return the <code>Point2D</code> in the destination that
455      *         corresponds to the specified point in the source.
456      */
457     public final Point2D getPoint2D (Point2D srcPt, Point2D dstPt) {
458         if (dstPt == null) {
459             dstPt = new Point2D.Float();
460         }
461         dstPt.setLocation(srcPt.getX(), srcPt.getY());
462 
463         return dstPt;
464     }
465 
466     /**
467      * Returns the rendering hints for this op.
468      * @return the <code>RenderingHints</code> object associated
469      *         with this op.
470      */
471     public final RenderingHints getRenderingHints() {
472         return hints;
473     }
474 
475     private final void byteFilter(ByteLookupTable lookup, Raster src,
476                                   WritableRaster dst,
477                                   int width, int height, int numBands) {
478         int[] srcPix = null;
479 
480         // Find the ref to the table and the offset
481         byte[][] table = lookup.getTable();
482         int offset = lookup.getOffset();
483         int tidx;
484         int step=1;
485 
486         // Check if it is one lookup applied to all bands
487         if (table.length == 1) {
488             step=0;
489         }
490 
491         int x;
492         int y;
493         int band;
494         int len = table[0].length;
495 
496         // Loop through the data
497         for ( y=0; y < height; y++) {
498             tidx = 0;
499             for ( band=0; band < numBands; band++, tidx+=step) {
500                 // Find data for this band, scanline
501                 srcPix = src.getSamples(0, y, width, 1, band, srcPix);
502 
503                 for ( x=0; x < width; x++) {
504                     int index = srcPix[x]-offset;
505                     if (index < 0 || index > len) {
506                         throw new
507                             IllegalArgumentException("index ("+index+
508                                                      "(out of range: "+
509                                                      " srcPix["+x+
510                                                      "]="+ srcPix[x]+
511                                                      " offset="+ offset);
512                     }
513                     // Do the lookup
514                     srcPix[x] = table[tidx][index];
515                 }
516                 // Put it back
517                 dst.setSamples(0, y, width, 1, band, srcPix);
518             }
519         }
520     }
521 
522     private final void shortFilter(ShortLookupTable lookup, Raster src,
523                                    WritableRaster dst,
524                                    int width, int height, int numBands) {
525         int band;
526         int[] srcPix = null;
527 
528         // Find the ref to the table and the offset
529         short[][] table = lookup.getTable();
530         int offset = lookup.getOffset();
531         int tidx;
532         int step=1;
533 
534         // Check if it is one lookup applied to all bands
535         if (table.length == 1) {
536             step=0;
537         }
538 
539         int x = 0;
540         int y = 0;
541         int index;
542         int maxShort = (1<<16)-1;
543         // Loop through the data
544         for (y=0; y < height; y++) {
545             tidx = 0;
546             for ( band=0; band < numBands; band++, tidx+=step) {
547                 // Find data for this band, scanline
548                 srcPix = src.getSamples(0, y, width, 1, band, srcPix);
549 
550                 for ( x=0; x < width; x++) {
551                     index = srcPix[x]-offset;
552                     if (index < 0 || index > maxShort) {
553                         throw new
554                             IllegalArgumentException("index out of range "+
555                                                      index+" x is "+x+
556                                                      "srcPix[x]="+srcPix[x]
557                                                      +" offset="+ offset);
558                     }
559                     // Do the lookup
560                     srcPix[x] = table[tidx][index];
561                 }
562                 // Put it back
563                 dst.setSamples(0, y, width, 1, band, srcPix);
564             }
565         }
566     }
567 }