public static unsafe Mat NormalizeTextImage(
Mat input,
TextImageHistStats stats,
Size size,
double noiseStdevFactor = 1)
{
var x0 = stats.X0;
var x1 = stats.X1;
using var inverse_ = x1 < x0 ? ~input : null;
using var inverse = inverse_ != null ? (Mat)inverse_ : null;
if (x1 < x0)
{
x0 = 255 - x0;
x1 = 255 - x1;
}
var background =
(byte)Math.Max((int)(x1 - stats.Stdev1 * noiseStdevFactor), 0);
var src = inverse ?? input;
using var mean = src.Blur(size);
var meanIndex = mean.GetUnsafeGenericIndexer <byte>();
var index = src.GetUnsafeGenericIndexer <byte>();
var normalized = new Mat(input.Size(), MatType.CV_8UC1);
normalized.ForEachAsByte((value, position) =>
{
var y = position[0];
var x = position[1];
var invalue = index[y, x];
var mean = meanIndex[y, x];
*value = mean < background ? invalue : background;
});
var k = 255.0 / (background - x0);
var lookup = new byte[256];
for (var i = 0; i < lookup.Length; ++i)
{
lookup[i] = i <= x0 ? (byte)0 : i >= x1 ?
(byte)255 : (byte)Math.Min((i - x0) * k, 255);
}
using var lut = InputArray.Create(lookup);
return(normalized.LUT(lut));
}
public static void Run()
{
using var scope = new Scope();
var ocrEngine = new TesseractEngine(
@"C:\projects\git\Cheques\Cheques\ChequeOCR\traindata\",
"eng+heb").In(scope);
using var input = Cv2.ImRead(@"C:\temp\images\cheque1.jpg", ImreadModes.Grayscale);
//using var input = Cv2.ImRead(@"C:\temp\images\cheque3.jpg", ImreadModes.Grayscale);
// using var input = Cv2.ImRead(@"C:\temp\images\cheque1-rotated15.jpg", ImreadModes.Grayscale);
//using var input = Cv2.ImRead(@"C:\projects\git\Cheques\Cheques\ChequeOCR\Lenna.png", ImreadModes.Grayscale);
//using var input = Cv2.ImRead(@"C:\temp\images\cheque1.jpg");
//using var filtered = input.PyrMeanShiftFiltering(10, 32);
//input.Dispose();
//using var src = filtered.CvtColor(ColorConversionCodes.RGB2GRAY);
//filtered.Dispose();
var src = input;
using var scaled = Scale(src, 1600);
//using var bilateral = scaled.BilateralFilter(7, 50, 50);
var background = GetBackground(scaled, .9);
TextImageHistStats stats = GetTextImageHistStats(scaled);
Console.WriteLine("Background: " + background);
//using
var masked =
//RemoveWatermark(scaled, background, new Size(3, 3));
//NormalizeTextImage(scaled, stats, new Size(7, 7));
NormalizeTextImage2(scaled, new Size(5, 5));
//var otsu = NormalizeTextImage2(scaled, new Size(5, 5));
//using(new Window("Otsu", WindowMode.Normal | WindowMode.KeepRatio, otsu))
//{
// Cv2.WaitKey();
//}
//using var clahe = Cv2.CreateCLAHE();
//var normalized = new Mat();
//clahe.Apply(masked, normalized);
//masked = normalized;
using var smooth = Smooth(masked, background, .1);
var stopwatch = new Stopwatch();
stopwatch.Start();
using var sharpened = Sharpen(smooth, new Size(13, 13));
//using var sharpened = Sharpen(scaled, new Size(10, 10));
stopwatch.Stop();
Console.WriteLine("Sharpen: " + stopwatch.ElapsedMilliseconds);
//using var blured = masked.GaussianBlur(new Size(25, 25), 0);
var featureInfo = Features(ocrEngine, masked, new Size(18, 18), background);
var features = sharpened.Clone();
features.DrawContours(featureInfo.Contours, -1, 64, 2);
//features.DrawContours(points3, -1, Scalar.WhiteSmoke, 2);
//foreach(var node in featureInfo.Nodes)
//{
// if (node?.Contours != null)
// {
// features.DrawContours(
// node.Contours,
// -1,
// 64,
// 2,
// LineTypes.Link4,
// null,
// int.MaxValue,
// new Point(node.Left, node.Top));
// }
//}
//sharpened.SaveImage(@"C:\temp\images\cheque1\cheque1-sharpened.jpg");
//var page = OCR(ocrEngine, sharpened, 225);
var nodes = featureInfo.Nodes.
Where(node => node != null).
OrderBy(node => node.Top).
ThenBy(node => node.Left).
ToList();
using (var ocrFile =
File.CreateText(@"C:\temp\images\cheque1\cheque1-sharpened-ocr.json"))
{
var json = JsonSerializer.Serialize(
nodes,
new JsonSerializerOptions
{
IgnoreNullValues = true,
WriteIndented = true,
Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
});
ocrFile.WriteLine(json);
}
//using var binaryMask = input.
// Threshold(100, 255, ThresholdTypes.BinaryInv | ThresholdTypes.Otsu).
// Dilate(Mat.Ones(18, 18, MatType.CV_8SC1));
using (new Window("Image", WindowMode.Normal | WindowMode.KeepRatio, scaled))
using (new Window("Masked", WindowMode.Normal | WindowMode.KeepRatio, masked))
//using(new Window("BinaryMask", WindowMode.Normal | WindowMode.KeepRatio, binaryMask))
using (new Window("Sharpened", WindowMode.Normal | WindowMode.KeepRatio, sharpened))
using (new Window("Features", WindowMode.Normal | WindowMode.KeepRatio, features))
{
Cv2.WaitKey();
}
}
