图片压缩

///原图压缩（压缩完直接nsdata类型保存到本地writeToFile）

- (NSData *)resetSizeOfImageData:(UIImage *)source_image

{

    NSData *data;

    if (UIImagePNGRepresentation(source_image) == nil) {

        data = UIImageJPEGRepresentation( source_image, 1);

    }else{

        data = UIImagePNGRepresentation(source_image);

        

    }

    //先调整分辨率

    CGFloat tempHeight;

    

    CGFloat tempWidth;

    UIImage *imghh = [UIImage imageWithData:data];

    CGSize newSize = CGSizeMake(imghh.size.width, imghh.size.height);

    if ( newSize.width<newSize.height){

        tempHeight = newSize.height / 1280;

        newSize = CGSizeMake(newSize.width/tempHeight, 1280);

    

    }else if (newSize.width>newSize.height){

        tempWidth = newSize.width / 1280;

        newSize = CGSizeMake(1280, newSize.height/tempWidth);

    }

    UIGraphicsBeginImageContext(newSize);

    [source_image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];

    

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    

    UIGraphicsEndImageContext();

    

    //调整大小

    NSData *imageData;

    imageData = UIImageJPEGRepresentation(newImage, 0.3);

    return imageData;

}