Cross-platform OCR processing library using PaddleOCR ONNX models, and based on original code from RapidAI's RapidOCR.
Available as NuGet package here https://www.nuget.org/packages/BrycensRanch.RapidOcrNet/
The code was optimised to remove dependencies on System.Drawing, OpenCV and SkiaSharp. The image processing is now done only using ImageSharp and PContourNet.
The project now uses PP-OCR v5 models, but v4 and v3 models are also supported (see here).
All ONNX models and files and can be downloaded from: https://github.com/RapidAI/RapidOCR/blob/main/python/rapidocr/default_models.yaml You will need 4 different files for the code to work. Example below for PP-OCR v5 with latin language:
- Detection:
ch_PP-OCRv5_mobile_det.onnx - Classification:
ch_ppocr_mobile_v2.0_cls_infer.onnx - Recognition:
latin_PP-OCRv5_rec_mobile_infer.onnx - Model dictionary:
ppocrv5_latin_dict.txt
string targetImg = "image.png";
// Where ONNX models downloaded from GitHub live
// The ONNX models are no longer copied to your publish directory.
string modelDir = Path.Combine(AppContext.BaseDirectory, "models");
using (var ocrEngine = new RapidOcr())
{
await ocrEngine.LoadModelAsync(OnnxModels.V5.EnglishMobile, modelDir, new HttpClient());
using (Image originSrc = Image.Load<Rgba32>(targetImg))
{
OcrResult ocrResult = ocrEngine.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;
originSrc.Mutate(ctx =>
{
ctx.DrawPolygon(Color.Red, 2f, points);
});
}
using (var fs = new FileStream(Path.ChangeExtension(targetImg, "_ocr.png"), FileMode.Create))
{
originSrc.SaveAsPng(fs);
}
}
}Based on source code originally developed in the RapidOCR project (Apache-2.0 license).
Uses parts of source code originally developed in the PdfPig project (Apache-2.0 license).
The dependency on OpenCV was removed thanks to the PContour library and its C# port.
The models made available are from the PaddleOCR project (Apache-2.0 license) and were downloaded from https://github.com/RapidAI/RapidOCR/blob/main/python/rapidocr/default_models.yaml