ios - UIImageJPEGRepresentation 和 UIImagePNGRepresentation 都很慢

Question

在这里，我在具有静态方法的 UIImage 上按类别将我的图像转换为二进制数据。我的问题是 UIImageJPEGRepresentation 和 UIImagePNGRepresentation 非常慢，最多 6 秒。我需要 1 秒的解决方案。有人可以帮助我吗？ 在这里，我将图像传递给类别方法，直到其大小减小到小于或等于 10kbs。

  -(NSData *)imageConvertToBinary :(UIImage *) image{

        NSLog(@"Image Convert  ");

        //UIImagePNGRepresentation(image);
        NSData *imageData = UIImageJPEGRepresentation(image, .000032);
         NSLog(@"Image Done  ");

        //Change size of image to 10kbs

        int size = imageData.length;
        NSLog(@"SIZE OF IMAGE:First %i ", size);
        NSData *data = UIImageJPEGRepresentation(image, .0032);
        NSLog(@"Start while  ");
        int temp=0;
        while (data.length / 1000 >= 10) {
            image = [UIImage imageWithImage:image andWidth:image.size.width/2 andHeight:image.size.height/2];

            data = UIImageJPEGRepresentation(image, .0032);
            temp++;
            NSLog(@"temp  %u",temp);

        }

        size = data.length;
        NSLog(@"SIZE OF IMAGE:after %i ", size);


        return data;

    }

and also i have category class on UIImage
@implementation UIImage (ImageProcessing)

+(UIImage*)imageWithImage:(UIImage*)image andWidth:(CGFloat)width andHeight:(CGFloat)height
{
    UIGraphicsBeginImageContext( CGSizeMake(width, height));
    [image drawInRect:CGRectMake(0,0,width,height)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}
@end

---

NSData *数据; 必须等于某物

Answer 1

我减少了你使用两倍以上 UIImageJPEGRepresentation 的代码试试这个

- (NSData *)imageConvertToBinary :(UIImage *) image{
    NSData *data ;
    NSLog(@"Start while  ");
    int temp=0;
    while (data.length / 1000 >= 10) {
        image = [UIImage imageWithImage:image andWidth:image.size.width/2 andHeight:image.size.height/2];
        data = UIImageJPEGRepresentation(image, .0032);
        temp++;
        NSLog(@"temp  %u",temp);
    }
    NSLog(@"End while  ");
    int size = data.length;
    NSLog(@"SIZE OF IMAGE:after %i ", size);
    return data;
}