iOS-image图片压缩

///压缩图片
+ (NSData *)imageCompressToData:(UIImage *)image{
    NSData *data=UIImageJPEGRepresentation(image, 1.0);
    if (data.length>300*1024) {
        if (data.length>1024*1024) {//1M以及以上
            data=UIImageJPEGRepresentation(image, 0.1);
        }else if (data.length>512*1024) {//0.5M-1M
            data=UIImageJPEGRepresentation(image, 0.5);
        }else if (data.length>300*1024) {//0.25M-0.5M
            data=UIImageJPEGRepresentation(image, 0.9);
        }
    }
    return data;
}