iOS 图片格式 图片压缩

#pragma mark ————————— 图片压缩 —————————————

+ (UIImage *)imageYaSuo:(UIImage *) image {

    

    NSData *data = nil;

    if(!UIImagePNGRepresentation(image)) {

        data =UIImageJPEGRepresentation(image,0.5);

    }else{

        data =UIImagePNGRepresentation(image);

    }

    CGFloat length = [data length] / 1024;

    NSLog(@"压缩完大小 = %.2f",length);

    UIImage *  newImage= [UIImageimageWithData:data];

    return newImage;

}

#pragma mark ————————— 图片格式 —————————————

+ (NSString *)typeForImageData:(NSData *)data {

    uint8_t c;

    [data getBytes:&c length:1];

    switch (c) {

        case 0xFF:

            return @"image/jpeg";

        case 0x89:

            return @"image/png";

        case 0x47:

            return @"image/gif";

        case 0x49:

        case 0x4D:

            return @"image/tiff";

    }

    return nil;

}