/// <summary>
/// Get borders of meaning part of image
/// </summary>
/// <param name="angle">Skew angle of image</param>
/// <param name="completedWidth">Width to which the image was completed</param>
/// /// <param name="resultWidth">Width of result (deskewed) image</param>
/// <param name="resultHeight">Height of result (deskewed) image</param>
/// <param name="projectedImage">Projected image</param>
/// <param name="originalWidth">Width of original image</param>
/// <param name="originalHeight">Height of original image</param>
/// <returns>Rectangle which bounds meaning part of image</returns>
private static Rectangle GetImageBordersWithoutWhiteSpaces(double angle, int completedWidth, int resultWidth, int resultHeight, KrecImage projectedImage, int originalWidth, int originalHeight)
{
var smallImage = BitmapProcessor.RotateGrayscaleImage(projectedImage, -angle); // Для скорости, границы обрезки ищем на уменьшенном изображении
var smallBinary = BitmapProcessor.BinarizeGrayscaleImage(smallImage);
var cutBorders = ImagePartitioner.GetImageWithoutBorders(smallBinary);
var k = (double)originalWidth / completedWidth;
var preComplementWidth = (int)(originalWidth / k);
var preComplementHeight = (int)(originalHeight / k);
var scaleRect = GetUnprojectedRectangle(cutBorders, projectionSideWidth, projectionSideWidth,
preComplementWidth, preComplementHeight,
originalWidth, originalHeight, angle);
int scaleXError = resultWidth / projectionSideWidth; //Увеличиваем с учетом погрешности
int scaleYError = resultHeight / projectionSideWidth;
scaleRect.X = Math.Max(scaleRect.X - scaleXError, 0);
scaleRect.Y = Math.Max(scaleRect.Y - scaleYError, 0);
scaleRect.Width = Math.Min(scaleRect.Width + scaleXError, resultWidth - scaleRect.X);
scaleRect.Height = Math.Min(scaleRect.Height + scaleYError, resultHeight - scaleRect.Y);
return(scaleRect);
}
/// <summary>
/// Fixing orientiation before returning scew angle
/// </summary>
/// <param name="originalImage">Original image</param>
/// <param name="preparedImage">Prepared for deskewing image</param>
/// <param name="angle">Calculated scew angle</param>
/// <param name="preComplementWidth">Width used when resizing</param>
/// <returns>Fixed descew angle</returns>
private static double FixDocumentOrientation(KrecImage originalImage, KrecImage preparedImage, double angle, int preComplementWidth)
{
var deskewedImage = BitmapProcessor.RotateGrayscaleImage(originalImage, -angle);
// TODO: бинаризацию можно сделать в этой точке, а не выполнять ее дважды в
// TODO: GetImageBordersWithoutWhiteSpaces и GetAngleToRightOrientation
var borders = GetImageBordersWithoutWhiteSpaces(angle, preComplementWidth, deskewedImage.Width, deskewedImage.Height, preparedImage, originalImage.Width, originalImage.Height);
var imagePart = deskewedImage.GetSubregion(borders);
var orientationResult = OrientationDeterminer.GetAngleToRightOrientation(imagePart);
double orientAngle = orientationResult;
double result = angle - orientAngle;
if (result > Math.PI)
{
result -= 2 * Math.PI;
}
else if (result < -Math.PI)
{
result += 2 * Math.PI;
}
return(result);
}