Adjustment Image

hi, everybody.
i tried to load image and create picture box with 152*152 size.
but loading image is larger than this box size.
so i need to adjust loaded image and show it in picture box.
here are some codes.

Code:

DialogResult dr = ofd_Finger.ShowDialog();

if (dr == DialogResult.OK)
            {
                Image loadimg = Image.FromFile(ofd_Finger.FileName);
                //pb_UserPhoto.Height = loadimg.Height;
                //pb_UserPhoto.Width = loadimg.Width;
                pb_UserPhoto.Image = loadimg;
            }

...........
can u help me?
best wishes.

I would create a second Bitmap and size the original image onto the new Bitmap. Example:

Code:

DialogResult dr = ofd_Finger.ShowDialog();

if (dr == DialogResult.OK)
{
    Image loadimg = Image.FromFile(ofd_Finger.FileName);
    pb_UserPhoto.Image = AdjustImageSize(loadimg, pb_UserPhoto.Width, pb_UserPhoto.Height);
}

And the AdjustImageSize code:

Code:

private static Image AdjustImageSize(Image source_image, int desired_width, int desired_height)
{
    Bitmap b = new Bitmap(desired_width, desired_height);
    Graphics g = Graphics.FromImage(b);
    g.DrawImage(source_image, new RectangleF(0, 0, desired_width, desired_height));
    return (Image)b;
}

I'd change 2 things with that code:

1. Call g.Dispose() before you leave the function; this will free up the resources used by the Graphics object. It will happen eventually, but garbage collection can take a while.

2. The default interpolation isn't very good. Setting

Code:

g.InterpolationMode = InterpolationMode.Bicubic;

(Or one of the other options if preferred) would be better.

Here's a piece of my code that does this. I pass the image by reference because I really don't care about the original (and I don't have any other references to the original apart from the one I pass in), so I trash the original and return the new image. If you cared about keeping the original image, you could of course do it your way, where it takes an image as a parameter and returns a new image as a return value.

Mine also has a preserve aspect ratio option -- that is, it will never return an image wider than w or taller than h, but it will keep the aspect ratio fixed if you set the fourth parameter to true. So e.g. a 300x600 image that was set to resize to 200x200 with aspect ratio preserved would actually become 100x200.

Code:

        private void ResizeImage(ref Image i, int w, int h, bool preserveAspectRatio, InterpolationMode mode)
        {
            int realWidth = w;
            int realHeight = h;
            if (preserveAspectRatio)
            {
                double hscale = (double)w / (double)i.Width;
                double vscale = (double)h / (double)i.Height;

                double scale = (hscale < vscale) ? hscale : vscale;

                // Rounded to nearest pixel
                realWidth = (int)(i.Width * scale + 0.5);
                realHeight = (int)(i.Height * scale + 0.5);

            }

            // Since copying or scaling a bitmap will use a crappy quality,
            // we need to make a new bitmap of the correct size, get the associated Graphic Context,
            // set the quality, and make a copy:

            Bitmap j = new Bitmap(realWidth, realHeight);  // New image
            Graphics g = Graphics.FromImage(j);
            g.InterpolationMode = mode;
            g.DrawImage(i, new Rectangle(0, 0, realWidth, realHeight));
            i.Dispose();  // Destroy the old image
            g.Dispose();
            i = j;        // Return the new one in our reference parameter.
        }

I'd never looked at InterpolationMode before. Thanks for pointing that one out. Learn something new everyday...

If you need a quick and easy solution, you can set the SizeMode property of the picturebox to Stretch.