Question

我正在关注Pro iOS 5增强现实版中的面部识别应用示例。我甚至下载了源代码......我从那里运行它，问题仍然存在于他的代码中。这是问题：它在一个数组的赋值上崩溃，该数组为正在检测面的CIDetector获取CGImage的featuresInImage。从日志记录......似乎这个方法被多次调用...我正在使用cocos2d_chipmunk所以我使用的是CSScene。请注意，此次崩溃是EXC_BAD_ACCESS (code=1, address=0x4499923c) 请帮忙吗？

  - (void)facialRecognitionRequest:(UIImage *)image {
//NSLog(@"Image is: %f by %f", image.size.width, image.size.height);
if (!isProcessingRequest) {
    isProcessingRequest = YES;
    //NSLog(@"Detecting Faces");
  NSArray* arr = [detector featuresInImage:[CIImage imageWithCGImage:[image CGImage]]]; // CRASHES HERE


    if ([arr count] > 0) {
        //NSLog(@"Faces found.");
        for (int i = 0; i < 1; i++) { //< [arr count]; i++) {
            CIFaceFeature *feature = [arr objectAtIndex:i];
            double xPosition = (feature.leftEyePosition.x + feature.rightEyePosition.x+feature.mouthPosition.x)/(3*image.size.width) ;
            double yPosition = (feature.leftEyePosition.y + feature.rightEyePosition.y+feature.mouthPosition.y)/(3*image.size.height);

            double dist = sqrt(pow((feature.leftEyePosition.x - feature.rightEyePosition.x),2)+pow((feature.leftEyePosition.y - feature.rightEyePosition.y),2))/image.size.width;

            yPosition += dist;
            CGSize size = [[CCDirector sharedDirector] winSize];
            pumpkin.opacity = 255;
            pumpkin.scale = 5*(size.width*dist)/256.0;

            //int randomPumpkin = ((arc4random() % 10) + 5);
            [pumpkin setDisplayFrame:[[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:[NSString stringWithFormat:@"pumpkin%d.png", pumpkin_count + 4]]];
            CCMoveTo *moveAction = [CCMoveTo actionWithDuration:0 position:ccp((size.width * (xPosition)), (size.height * ((yPosition))))];
            [pumpkin runAction:moveAction];

        }
    } else {
        pumpkin.opacity = 0;

    }    


}
isProcessingRequest = NO;

  }

分配CIDetector：

  - (id)init {
if (self = [super init]) {
  // ....... other stuff here        
    NSDictionary *detectorOptions = [NSDictionary dictionaryWithObjectsAndKeys:CIDetectorAccuracyLow, CIDetectorAccuracy, nil];
    self.detector = [CIDetector detectorOfType:CIDetectorTypeFace context:nil options:detectorOptions]; // CIDetector instance named detector is my property

}
return self;
 }

我试过了： CGImage * theCGImage = [image CGImage]; NSLog（@“theCGImage：％@”，theCGImage）;

CIImage *theCIImage = [CIImage imageWithCGImage:theCGImage];
NSLog(@"theCIImage: %@", theCIImage);

NSArray* arr = [detector featuresInImage:theCIImage];
NSLog(@"arr: %@", arr);

结果如下：

 2012-04-15 19:08:25.136 Ch8[981:609f] tmpCGImage: <CGImage 0x1f689c00>
 2012-04-15 19:08:25.143 Ch8[981:609f] tmpCIImage: <CIImage: 0x1f687970 extent [0 0 480 360]>
 2012-04-15 19:08:25.282 Ch8[981:609f] arr: (
"<CIFaceFeatureInternal: 0x1f58e080>"
)

我也试过启用NSZombies，但仍然没有运气......任何想法？

Answer 1

回答评论（不是整个问题，仅作为格式的答案）：
“我该怎么做呢？我只是写if语句，看看它们是否为非零然后记录它？”

而不是：

  NSArray* arr = [detector featuresInImage:[CIImage imageWithCGImage:[image CGImage]]];

将其分为三个陈述：

CGImage *theCGImage = [image CGImage];
NSLog(@"theCGImage: %@", theCGImage);

CIImage *theCIImage = [CIImage imageWithCGImage:theCGImage];
NSLog(@"theCIImage: %@", theCIImage);

NSArray* arr = [detector featuresInImage:theCIImage];
NSLog(@"arr: %@", arr);

这样就可以找到违规的陈述。这是一种通用的调试技术，在任何情况下都不是编写代码的坏方法。

NSLog语句不是必需的，是第一个语句的断点，然后单步执行。

对于因过早发布而导致的崩溃，请使用NSZombies。它可以在Xcode中的“编辑方案，选项卡：”诊断“下启用，确保在设备上运行时将其关闭。

enter image description here

Answer 2

检查是否添加了异常断点。以我为例，在功能函数调用中引发了异常，而试图捕获该异常的断点导致崩溃。通过从“断点”列表中删除“异常断点”，崩溃消失了。

数组分配的EXC_BAD_ACCESS（CIDetector featuresInImage）

2 个答案: