iphone/ZXingWidget/Classes/Decoder.mm

   1 //
   2 //  Decoder.m
   3 //  ZXing
   4 //
   5 //  Created by Christian Brunschen on 31/03/2008.
   6 //
   7 /*
   8  * Copyright 2008 ZXing authors
   9  *
  10  * Licensed under the Apache License, Version 2.0 (the "License");
  11  * you may not use this file except in compliance with the License.
  12  * You may obtain a copy of the License at
  13  *
  14  *      http://www.apache.org/licenses/LICENSE-2.0
  15  *
  16  * Unless required by applicable law or agreed to in writing, software
  17  * distributed under the License is distributed on an "AS IS" BASIS,
  18  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  19  * See the License for the specific language governing permissions and
  20  * limitations under the License.
  21  */
  22
  23 #import "Decoder.h"
  24 #import "TwoDDecoderResult.h"
  25 #import "FormatReader.h"
  26
  27 #include <zxing/BinaryBitmap.h>
  28 #include <zxing/ReaderException.h>
  29 #include <zxing/common/IllegalArgumentException.h>
  30 #include <zxing/common/GlobalHistogramBinarizer.h>
  31 #include <zxing/common/GreyscaleLuminanceSource.h>
  32
  33 using namespace zxing;
  34
  35 @implementation Decoder
  36
  37 @synthesize image;
  38 @synthesize cropRect;
  39 @synthesize subsetImage;
  40 @synthesize subsetData;
  41 @synthesize subsetWidth;
  42 @synthesize subsetHeight;
  43 @synthesize subsetBytesPerRow;
  44 @synthesize delegate;
  45 @synthesize operationQueue;
  46 @synthesize readers;
  47
  48
  49 - (id)init {
  50   if (self = [super init]) {
  51     NSOperationQueue *opQueue = [[NSOperationQueue alloc] init];
  52     self.operationQueue = opQueue;
  53     [opQueue release];
  54   }
  55   return self;
  56 }
  57 - (void)willDecodeImage {
  58   if ([self.delegate respondsToSelector:@selector(decoder:willDecodeImage:usingSubset:)]) {
  59     [self.delegate decoder:self willDecodeImage:self.image usingSubset:self.subsetImage];
  60   }
  61 }
  62
  63 - (void)progressDecodingImage:(NSString *)progress {
  64   if ([self.delegate respondsToSelector:@selector(decoder:decodingImage:usingSubset:progress:)]) {
  65     [self.delegate decoder:self decodingImage:self.image usingSubset:self.subsetImage progress:progress];
  66   }
  67 }
  68
  69 - (void)didDecodeImage:(TwoDDecoderResult *)result {
  70
  71   if ([self.delegate respondsToSelector:@selector(decoder:didDecodeImage:usingSubset:withResult:)]) {
  72     [self.delegate decoder:self didDecodeImage:self.image usingSubset:self.subsetImage withResult:result];
  73   }
  74
  75   [result release];
  76 }
  77
  78 - (void)failedToDecodeImage:(NSString *)reason {
  79
  80   if ([self.delegate respondsToSelector:@selector(decoder:failedToDecodeImage:usingSubset:reason:)]) {
  81     [self.delegate decoder:self failedToDecodeImage:self.image usingSubset:self.subsetImage reason:reason];
  82   }
  83 }
  84
  85 #define SUBSET_SIZE 320.0
  86 - (void) prepareSubset {
  87   CGSize size = [image size];
  88 #ifdef DEBUG
  89   NSLog(@"decoding: image is (%.1f x %.1f), cropRect is (%.1f,%.1f)x(%.1f,%.1f)", size.width, size.height,
  90       cropRect.origin.x, cropRect.origin.y, cropRect.size.width, cropRect.size.height);
  91 #endif
  92   float scale = fminf(1.0f, fmaxf(SUBSET_SIZE / cropRect.size.width, SUBSET_SIZE / cropRect.size.height));
  93   CGPoint offset = CGPointMake(-cropRect.origin.x, -cropRect.origin.y);
  94 #ifdef DEBUG
  95   NSLog(@"  offset = (%.1f, %.1f), scale = %.3f", offset.x, offset.y, scale);
  96 #endif
  97
  98   subsetWidth = cropRect.size.width * scale;
  99   subsetHeight = cropRect.size.height * scale;
 100
 101   subsetBytesPerRow = ((subsetWidth + 0xf) >> 4) << 4;
 102 #ifdef DEBUG
 103   NSLog(@"decoding: image to decode is (%d x %d) (%d bytes/row)", subsetWidth, subsetHeight, subsetBytesPerRow);
 104 #endif
 105
 106   subsetData = (unsigned char *)malloc(subsetBytesPerRow * subsetHeight);
 107 #ifdef DEBUG
 108   NSLog(@"allocated %d bytes of memory", subsetBytesPerRow * subsetHeight);
 109 #endif
 110
 111   CGColorSpaceRef grayColorSpace = CGColorSpaceCreateDeviceGray();
 112
 113   CGContextRef ctx =
 114   CGBitmapContextCreate(subsetData, subsetWidth, subsetHeight,
 115               8, subsetBytesPerRow, grayColorSpace,
 116               kCGImageAlphaNone);
 117   CGColorSpaceRelease(grayColorSpace);
 118   CGContextSetInterpolationQuality(ctx, kCGInterpolationNone);
 119   CGContextSetAllowsAntialiasing(ctx, false);
 120   // adjust the coordinate system
 121   CGContextTranslateCTM(ctx, 0.0, subsetHeight);
 122   CGContextScaleCTM(ctx, 1.0, -1.0);
 123
 124 #ifdef DEBUG
 125   NSLog(@"created %dx%d bitmap context", subsetWidth, subsetHeight);
 126 #endif
 127
 128   UIGraphicsPushContext(ctx);
 129   CGRect rect = CGRectMake(offset.x * scale, offset.y * scale, scale * size.width, scale * size.height);
 130 #ifdef DEBUG
 131   NSLog(@"rect for image = (%.1f,%.1f)x(%.1f,%.1f)", rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
 132 #endif
 133   [image drawInRect:rect];
 134   UIGraphicsPopContext();
 135
 136 #ifdef DEBUG
 137   NSLog(@"drew image into %d(%d)x%d  bitmap context", subsetWidth, subsetBytesPerRow, subsetHeight);
 138 #endif
 139   CGContextFlush(ctx);
 140 #ifdef DEBUG
 141   NSLog(@"flushed context");
 142 #endif
 143
 144   CGImageRef subsetImageRef = CGBitmapContextCreateImage(ctx);
 145 #ifdef DEBUG
 146   NSLog(@"created CGImage from context");
 147 #endif
 148
 149   self.subsetImage = [UIImage imageWithCGImage:subsetImageRef];
 150   CGImageRelease(subsetImageRef);
 151
 152   CGContextRelease(ctx);
 153 #ifdef DEBUG
 154   NSLog(@"released context");
 155 #endif
 156 }
 157
 158 - (void)decode:(id)arg {
 159   NSAutoreleasePool* mainpool = [[NSAutoreleasePool alloc] init];
 160   {
 161     //NSSet *formatReaders = [FormatReader formatReaders];
 162     NSSet *formatReaders = self.readers;
 163     Ref<LuminanceSource> source
 164            (new GreyscaleLuminanceSource(subsetData, subsetBytesPerRow, subsetHeight, 0, 0, subsetWidth, subsetHeight));
 165     Ref<Binarizer> binarizer (new GlobalHistogramBinarizer(source));
 166     Ref<BinaryBitmap> grayImage (new BinaryBitmap(binarizer));
 167 #ifdef DEBUG
 168     NSLog(@"created GreyscaleLuminanceSource", subsetWidth, subsetHeight);
 169     NSLog(@"grayImage count = %d", grayImage->count());
 170 #endif
 171
 172     TwoDDecoderResult *decoderResult = nil;
 173
 174 #ifdef TRY_ROTATIONS
 175     for (int i = 0; !decoderResult && i < 4; i++) {
 176 #endif
 177       for (FormatReader *reader in formatReaders) {
 178         NSAutoreleasePool *secondarypool = [[NSAutoreleasePool alloc] init];
 179         try {
 180   #ifdef DEBUG
 181           NSLog(@"decoding gray image");
 182   #endif
 183           Ref<Result> result([reader decode:grayImage]);
 184   #ifdef DEBUG
 185           NSLog(@"gray image decoded");
 186   #endif
 187
 188           Ref<String> resultText(result->getText());
 189           const char *cString = resultText->getText().c_str();
 190           const std::vector<Ref<ResultPoint> > &resultPoints = result->getResultPoints();
 191           NSMutableArray *points =
 192             [[NSMutableArray alloc ] initWithCapacity:resultPoints.size()];
 193
 194           for (size_t i = 0; i < resultPoints.size(); i++) {
 195             const Ref<ResultPoint> &rp = resultPoints[i];
 196             CGPoint p = CGPointMake(rp->getX(), rp->getY());
 197             [points addObject:[NSValue valueWithCGPoint:p]];
 198           }
 199
 200           NSString *resultString = [NSString stringWithCString:cString
 201                                 encoding:NSUTF8StringEncoding];
 202
 203           decoderResult = [[TwoDDecoderResult resultWithText:resultString
 204                                                      points:points] retain];
 205           [points release];
 206         } catch (ReaderException &rex) {
 207           NSLog(@"failed to decode, caught ReaderException '%s'",
 208               rex.what());
 209         } catch (IllegalArgumentException &iex) {
 210           NSLog(@"failed to decode, caught IllegalArgumentException '%s'",
 211               iex.what());
 212         } catch (...) {
 213           NSLog(@"Caught unknown exception!");
 214         }
 215         [secondarypool release];
 216       }
 217
 218 #ifdef TRY_ROTATIONS
 219       if (!decoderResult) {
 220 #ifdef DEBUG
 221         NSLog(@"rotating gray image");
 222 #endif
 223         grayImage = grayImage->rotateCounterClockwise();
 224 #ifdef DEBUG
 225         NSLog(@"gray image rotated");
 226 #endif
 227       }
 228     }
 229 #endif
 230
 231         free(subsetData);
 232         self.subsetData = NULL;
 233
 234     if (decoderResult) {
 235       [self performSelectorOnMainThread:@selector(didDecodeImage:)
 236                    withObject:decoderResult
 237                 waitUntilDone:NO];
 238     } else {
 239       [self performSelectorOnMainThread:@selector(failedToDecodeImage:)
 240                    withObject:NSLocalizedString(@"Decoder BarcodeDetectionFailure", @"No barcode detected.")
 241                 waitUntilDone:NO];
 242     }
 243   }
 244
 245
 246 #ifdef DEBUG
 247   NSLog(@"finished decoding.");
 248 #endif
 249   [mainpool release];
 250 }
 251
 252 - (void) decodeImage:(UIImage *)i {
 253   [self decodeImage:i cropRect:CGRectMake(0.0f, 0.0f, i.size.width, i.size.height)];
 254 }
 255
 256
 257 - (void) asyncDecodeImage {
 258   [self prepareSubset];
 259   [self willDecodeImage];
 260   [self performSelectorOnMainThread:@selector(willDecodeImage)
 261                          withObject:nil
 262                       waitUntilDone:NO];
 263   [self performSelectorOnMainThread:@selector(progressDecodingImage:)
 264                          withObject:NSLocalizedString(@"Decoder MessageWhileDecoding", @"Decoding ...")
 265                       waitUntilDone:NO];
 266 /*  NSInvocationOperation *op = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(decode:) object:nil];
 267   [operationQueue addOperation:op];
 268   [op release];*/
 269   [self decode:nil];
 270 }
 271 - (void) decodeImage:(UIImage *)i cropRect:(CGRect)cr {
 272   self.image = i;
 273   self.cropRect = cr;
 274   NSInvocationOperation *op = [[NSInvocationOperation  alloc] initWithTarget:self selector:@selector(asyncDecodeImage) object:nil];
 275   [operationQueue addOperation:op];
 276   [op release];
 277 }
 278
 279 - (void) dealloc {
 280
 281   [image release];
 282   [subsetImage release];
 283   if (subsetData) free(subsetData);
 284   [operationQueue release];
 285   [readers release];
 286   [super dealloc];
 287 }
 288
 289 @end