README.md

RapidOcrNet

Cross-platform OCR processing library using PaddleOCR ONNX models, and based on original code from RapidAI's RapidOCR.

The code was optimised to remove dependencies on System.Drawing and OpenCV. The image processing is now done only using SkiaSharp and PContourNet.

Usage

string targetImg = "image.png";

using (var ocrEngin = new RapidOcr())
{
	ocrEngin.InitModels();
	using (SKBitmap originSrc = SKBitmap.Decode(targetImg))
	{
		OcrResult ocrResult = ocrEngin.Detect(originSrc, RapidOcrOptions.Default);
		Console.WriteLine(ocrResult.ToString());
		Console.WriteLine(ocrResult.StrRes);
		Console.WriteLine();

		// Draw bounding boxes
		foreach (var block in ocrResult.TextBlocks)
		{
			var points = block.BoxPoints;
			using (var canvas = new SKCanvas(originSrc))
			using (var paint = new SKPaint() { Color = SKColors.Red })
			{
				canvas.DrawLine(points[0], points[1], paint);
				canvas.DrawLine(points[1], points[2], paint);
				canvas.DrawLine(points[2], points[3], paint);
				canvas.DrawLine(points[3], points[0], paint);
			}
		}

		using (var fs = new FileStream(Path.ChangeExtension(targetImg, "_ocr.png"), FileMode.Create))
		{
			originSrc.Encode(fs, SKEncodedImageFormat.Png, 100);
		}
	}
}

Notice

Based on source code originally developed in the RapidOCR project (Apache-2.0 license).

• https://github.com/RapidAI/RapidOCR

Uses parts of source code originally developed in the PdfPig project (Apache-2.0 license).

• https://github.com/UglyToad/PdfPig

The dependency on OpenCV was removed thanks to the PContour library and its C# port.

• https://github.com/LingDong-/PContour
• https://github.com/BobLd/PContourNet

The models made available are from the PaddleOCR project (Apache-2.0 license) and were converted to ONNX using the Paddle2ONNX tool.

• https://paddlepaddle.github.io/PaddleOCR/en/ppocr/model_list.html
• https://github.com/PaddlePaddle/Paddle2ONNX