图片压缩后长度和宽度 及像素坐标

图片压缩后长度和宽度 及像素坐标

CGFloat    scaleFloat = 0.6;
+ (UIImage *) scaleImage: (UIImage *)image scaleFactor:(float)scaleFloat
{
    CGSize size = CGSizeMake(image.size.width * scaleBy, image.size.height * scaleBy);

    UIGraphicsBeginImageContext(size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGAffineTransform transform = CGAffineTransformIdentity;

    transform = CGAffineTransformScale(transform, scaleBy, scaleBy);
    CGContextConcatCTM(context, transform);

    // Draw the image into the transformed context and return the image
    [image drawAtPoint:CGPointMake(0.0f, 0.0f)];
    UIImage *newimg = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newimg;  
}

然后imgData = UIImageJPEGRepresentation(image, 0.6f)
imgData UIImageJPEGRepresentation(image, scaleFloat)