public static Image ResizeImageForCognitiveOCR(Image image)//, int width, int height)
{
// If image is less than 3200x3200 return it
if (image.Height <= 4200 && image.Width <= 4200)
{
return(image);
}
// Rescale the image for max 3150 x 3150 (below 3200 x 3200)
var originalWidth = image.Size.Width;
var originalHeight = image.Size.Height;
var width = 4000;
var height = 4000;
// Figure out the ratio
double ratioX = (double)width / (double)originalWidth;
double ratioY = (double)height / (double)originalHeight;
// use whichever multiplier is smaller
double ratio = ratioX < ratioY ? ratioX : ratioY;
// now we can get the new height and width
int newHeight = Convert.ToInt32(originalHeight * ratio);
int newWidth = Convert.ToInt32(originalWidth * ratio);
var destRect = new Rectangle(0, 0, newWidth, newHeight);
var destImage = new Bitmap(newWidth, newHeight);
// Now calculate the X,Y position of the upper-left corner
// (one of these will always be zero)
int posX = Convert.ToInt32((newWidth - (originalWidth * ratio)) / 2);
int posY = Convert.ToInt32((newHeight - (originalHeight * ratio)) / 2);
destImage.SetResolution(image.HorizontalResolution, image.VerticalResolution);
using (var graphics = Graphics.FromImage(destImage))
{
graphics.CompositingMode = CompositingMode.SourceCopy;
//graphics.CompositingQuality = CompositingQuality.HighQuality;
//graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
//graphics.SmoothingMode = SmoothingMode.HighQuality;
//graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
using (var wrapMode = new ImageAttributes())
{
wrapMode.ClearBrushRemapTable();
wrapMode.ClearGamma();
wrapMode.ClearColorMatrix();
wrapMode.SetWrapMode(WrapMode.Tile);
graphics.Clear(Color.White);
//graphics.DrawRectangle(new Pen(new SolidBrush(Color.White)), 0, 0, newWidth, newHeight);
graphics.DrawImage(image, destRect, posX, posY, image.Width, image.Height, GraphicsUnit.Pixel, wrapMode);
}
}
// Ensure image doesn't have a transparency layer
Bitmap temp = new Bitmap(destImage.Width, destImage.Height, PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(temp);
g.Clear(Color.White);
g.DrawImage(destImage, Point.Empty);
return(temp);
// return destImage;
}