public MemoryStream ResizeImage(Stream imageStream, ImageSizes size)
{
var newHeight = size.Size().Height;
var newWidth = size.Size().Width;
var oldImage = System.Drawing.Image.FromStream(imageStream);
double oldHeight = oldImage.Height;
double oldWidth = oldImage.Width;
var widthChange = Math.Abs(newWidth - oldWidth);
var heightChange = Math.Abs(newHeight - oldHeight);
var greatestChangeDimension = (widthChange > heightChange) ? Dimensions.Width : Dimensions.Height;
if(greatestChangeDimension == Dimensions.Width)
{
var ratio = (1/(oldWidth/oldHeight));
newHeight = newWidth * ratio;
}
if(greatestChangeDimension == Dimensions.Height)
{
var ratio = (1/(oldWidth/oldHeight));
newWidth = newHeight * ratio;
}
var newImage = new Bitmap(oldImage, new Size((int) Math.Floor(newWidth), (int) Math.Floor(newHeight)));
var newImageMemoryStream = new MemoryStream();
newImage.Save(newImageMemoryStream, ImageFormat.Png);
return newImageMemoryStream;
}
