/// <summary>
/// Image preparing process. Resizing and fixing quality.
/// </summary>
/// <param name="originalImage">Original image</param>
/// <param name="preComplementWidth">Width used when resizing</param>
/// <returns>Grayscaled image for descewing</returns>
private static KrecImage PrepareImageForDeskewing(KrecImage originalImage, out int preComplementWidth)
{
if (originalImage.HorizontalResolution > maxDpi)
{
// TODO: make k be integer to avoid resampling errors
double k = maxDpi / originalImage.HorizontalResolution;
originalImage = ImageSizesModifier.CompressImageToNewSizes(originalImage, (int)Math.Round(originalImage.Width * k),
(int)Math.Round(originalImage.Height * k));
}
KrecImage projectionImage;
preComplementWidth = Math.Min(projectionSideWidth, originalImage.Width);
if (originalImage.Height < maxCompletedSideWith && originalImage.Width < maxCompletedSideWith) //имитирует поведение прошлого сжимателя
{
int dx = (maxCompletedSideWith - originalImage.Width) / 2;
int dy = (maxCompletedSideWith - originalImage.Height) / 2;
int newWidth = projectionSideWidth - dx;
int newHeight = projectionSideWidth - dy;
double k = Math.Max((double)originalImage.Height / newHeight, (double)originalImage.Width / newWidth);
var compressedImage = ImageSizesModifier.CompressImageToNewSizes(originalImage,
(int)(originalImage.Width / k), (int)(originalImage.Height / k));
compressedImage = BitmapProcessor.AlignImageBackround(compressedImage);
preComplementWidth = (int)(originalImage.Width / k);
projectionImage = ImageSizesModifier.GetImageWithPowerOf2Side(compressedImage, projectionSideWidth);
}
else
{
var alignedImage = BitmapProcessor.AlignImageBackround(originalImage);
projectionImage = ImageSizesModifier.GetImageWithPowerOf2Side(alignedImage, projectionSideWidth);
}
return(projectionImage);
}
/// <summary>
/// Get coordinates of rectangle from deskewed projected image in original image
/// </summary>
/// <param name="projectedRectangle">Rectangle from deskewed projected image</param>
/// <param name="projectedImageWidth">Projected image width (before deskewing)</param>
/// <param name="projectedImageHeight">Projected image height (before deskewing)</param>
/// <param name="preComplementImageWidth">Width of image before it was completed to power of 2</param>
/// <param name="preComplementImageHeight">Height of image before it was completed to power of 2</param>
/// <param name="originalImageWidth">Original image width</param>
/// <param name="originalImageHeight">Original image Height</param>
/// <param name="rotationAngle">Images skew angle</param>
/// <returns>Rectangle in original image</returns>
private static Rectangle GetUnprojectedRectangle(Rectangle projectedRectangle, int projectedImageWidth,
int projectedImageHeight, int preComplementImageWidth, int preComplementImageHeight, int originalImageWidth,
int originalImageHeight, double rotationAngle)
{
var points = new[]
{
new Point(projectedRectangle.Left, projectedRectangle.Top),
new Point(projectedRectangle.Right, projectedRectangle.Bottom)
};
var rotatedPoints = ImageSizesModifier.GetPointsBeforeRotation(points, -rotationAngle,
projectedImageWidth, projectedImageHeight);
var scale = (double)preComplementImageWidth / originalImageWidth;
var dy = (projectedImageHeight - preComplementImageHeight) / 2;
var dx = (projectedImageWidth - preComplementImageWidth) / 2;
var descaledPoints = rotatedPoints
.Select(p => new Point((int)((p.X - dx) / scale), (int)((p.Y - dy) / scale))).ToList();
var result = ImageSizesModifier
.RotatePoints(descaledPoints, -rotationAngle, originalImageWidth, originalImageHeight).ToList();
return(new Rectangle(result[0].X, result[0].Y, result[1].X - result[0].X, result[1].Y - result[0].Y));
}
