thumbnail, cut resize and upload to DB - c#-4.0

Question

I use this code to create thumbnails and then store the original and the thumbnail into a DB. It creates tn that are always of a fixed sized and if the original image is wither than it's higher it is cut and then resized to the fixed size.
The code is working however I would really appreciate some help modifying this code to do the following (I have tried it but didn't succeeded):
Make high-quality thumbnails
cut the height if the image is way taller
than it's width (If the width is
200px and height is 1000px what will
happen?)
Accept png and tiff.
This is the code so far:
public void imgUpload()
{
if (ImgUpload.PostedFile != null)
{
System.Drawing.Image image_file = System.Drawing.Image.FromStream(ImgUpload.PostedFile.InputStream);
string fileName = Server.HtmlEncode(ImgUpload.FileName);
string extension = System.IO.Path.GetExtension(fileName);
bool sizeError = false;
if(image_file.Width < 200)
sizeError = true;
if(image_file.Height < 250)
sizeError = true;
if ((extension.ToUpper() == ".JPG") && !sizeError)
{
//**** Resize image section ****
int image_height = image_file.Height;
int image_width = image_file.Width;
int original_width = image_width;
int original_height = image_height;
int max_height = 250;
int max_width = 200;
Rectangle rect;
if (image_width > image_height)
{
image_width = (image_width * max_height) / image_height;
image_height = max_height;
rect = new Rectangle(((image_width - max_width) / 2), 0, max_width, max_height);
}
else
{
image_height = (image_height * max_width) / image_width;
image_width = max_width;
rect = new Rectangle(0, ((image_height - max_height) / 2), max_width, max_height);
}
Bitmap bitmap_file = new Bitmap(image_file, image_width, image_height);
Bitmap new_bitmap_file = bitmap_file.Clone(rect, bitmap_file.PixelFormat);
System.IO.MemoryStream stream = new System.IO.MemoryStream();
new_bitmap_file.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
stream.Position = 0;
byte[] imageThumbnail = new byte[stream.Length + 1];
stream.Read(imageThumbnail, 0, imageThumbnail.Length);
Bitmap Original_bitmap_file = new Bitmap(image_file, original_width, original_height);
System.IO.MemoryStream Original_stream = new System.IO.MemoryStream();
Original_bitmap_file.Save(Original_stream, System.Drawing.Imaging.ImageFormat.Jpeg);
Original_stream.Position = 0;
byte[] imageOriginal = new byte[Original_stream.Length + 1];
Original_stream.Read(imageOriginal, 0, imageOriginal.Length);
//**** End resize image section ****
saveImage(imageThumbnail, imageOriginal, IDTextBox.Text);
lblOutput.Visible = false;
}
else
{
lblOutput.Text = "Please only upload .jpg files and make sure the size is minimum 200x250";
lblOutput.Visible = true;
}
}
else
{
lblOutput.Text = "No file selected";
lblOutput.Visible = true;
}
}

Answer 1

Here is an example of how to scale and crop an image:
Bitmap b = new Bitmap(200, 1000);
using (var g = Graphics.FromImage(b))
{
g.DrawLine(Pens.White, 0, 0, b.Width, b.Height);
}
b.Save("b.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
Bitmap thumb = new Bitmap(100, 100);
using (var g = Graphics.FromImage(thumb))
{
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
g.DrawImage(b, new Rectangle(0,0,100,100), new Rectangle(0, 400, 200, 200), GraphicsUnit.Pixel);
}
thumb.Save("thumb.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
I think you can adapt the code to all what's and if's about when the ratio height/width is to high, etc.

Answer 2

I use the following code when creating thumbnails for http://www.inventerat.se and a few other sites and it works like a charm:
public static Bitmap WithinMaxSize(Image imgPhoto, int maxWidth, int maxHeight)
{
int sourceWidth = imgPhoto.Width;
int sourceHeight = imgPhoto.Height;
int destWidth;
int destHeight;
float sourceAspect = sourceWidth / (sourceHeight * 1.0F);
float maxAspect = maxWidth / (maxHeight * 1.0F);
if (sourceAspect > maxAspect)
{
// Width is limiting.
destWidth = maxWidth;
destHeight = (int)Math.Round(destWidth / sourceAspect);
}
else
{
// Height is limiting.
destHeight = maxHeight;
destWidth = (int)Math.Round(destHeight * sourceAspect);
}
Bitmap bmPhoto = new Bitmap(destWidth, destHeight);
Graphics grPhoto = Graphics.FromImage(bmPhoto);
grPhoto.Clear(Color.White);
grPhoto.CompositingMode = CompositingMode.SourceCopy;
grPhoto.CompositingQuality = CompositingQuality.HighQuality;
grPhoto.InterpolationMode = InterpolationMode.HighQualityBicubic;
grPhoto.DrawImage(imgPhoto, 0, 0, destWidth, destHeight);
grPhoto.Dispose();
return bmPhoto;
}
Just don't forget to dispose the Bitmap returned from this method.
It does not work very well if users are uploading very large images (e.g. > 5000 * 5000 pixels) though. If that is a requirement, I would recommend using ImageMagick or a similar imaging package.
To accept png and tiff, just adjust how You check the file extension so that You accept "png", "tif" and "tiff" as well. Support for tiff is a bit sketchy in .NET though since tiff itself is only a container for MANY different encodings.