图片分割的代码

/*

 +(NSDictionary*)SeparateImage:(UIImage*)image ByX:(int)x andY:(int)y cacheQuality:(float)quality;
 
 方法说明：
 NSDictionary *：返回字典，UIImageView格式，不仅含有 Image 还含有 Rect。
 image: 图片资源，要求为UIImage格式。x: y:分别表示要切成几行和列，最小值为1。
 quality：处理后保存的小图片的质量。（0，1］有效，小于或为0不保存，大于1时会被强强制为1。
 切割后的小图片保存位置为 Homedirectory， 可以通过 nslog(@"%@",NSHomedirectory()); 查出。
 
 用途：
 适合图片处理应用里为图片添加百叶窗效果，或者拼图游戏里...
 
 */

+(NSDictionary*)SeparateImage:(UIImage*)image ByX:(int)x andY:(int)y cacheQuality:(float)quality
{
    //kill errors
    if (x<1) {
        NSLog(@"illegal x!");
        return nil;
    }else if (y<1) {
        NSLog(@"illegal y!");
        return nil;
    }
    
    if (![image isKindOfClass:[UIImage class]]) {
        NSLog(@"illegal image format!");
        return nil;
    }
    
    //attributes of element
    float _xstep=image.size.width*1.0/(y+1);
    float _ystep=image.size.height*1.0/(x+1);
    
    NSMutableDictionary*_mutableDictionary = [[NSMutableDictionary alloc]initWithCapacity:1];
    
    //NSArray*_array=[imageName componentsSeparatedByString:@"."];
    
    //NSString*prefixName=[_array objectAtIndex:0];
    
    NSString*prefixName=@"win";
    
    //snap in context and create element image view
    for (int i=0; i<x; i++)
    {
        for (int j=0; j<y; j++)
        {
            CGRect rect=CGRectMake(_xstep*j, _ystep*i, _xstep, _ystep);
            
            CGImageRef imageRef=CGImageCreateWithImageInRect([image CGImage],rect);
           
            UIImage* elementImage=[UIImage imageWithCGImage:imageRef];
            
            UIImageView*_imageView=[[UIImageView alloc] initWithImage:elementImage];
            
            _imageView.frame=rect;
            
            NSString*_imageString=[NSString stringWithFormat:@"%@_%d_%d.jpg",prefixName,i,j];
            
            [_mutableDictionary setObject:_imageView forKey:_imageString];
            
            //CFRelease(imageRef);
            
            if (quality<=0)
            {
                continue;
            }
            
            quality=(quality>1)?1:quality;
            
            NSString*_imagePath=[NSHomeDirectory() stringByAppendingPathComponent:_imageString];
           
            NSData* _imageData=UIImageJPEGRepresentation(elementImage, quality);
            
            [_imageData writeToFile:_imagePath atomically:NO];
            
        }
        
    }
    
    //return dictionary including image views
    NSDictionary*_dictionary=_mutableDictionary;
    return _dictionary;
    
}