Why IronOCR and not Tesseract
Accuracy
Tesseract:
- Tesseract unable to handle an image that is rotated, skewed, low DPI, scanned, or has background noise
- Requires image pre-processing using Photoshop or ImageMagick
- Long processing time before providing nonsensical information
IronOCR:
- IronOCR pre-processing and image filters take this headache away
- Users often achieve 99.8-100% accuracy with minimal configuration
Image Compatibility
Tesseract:
- Only accepts Leptonica PIX image format which is an IntPtr C++ object in C#
- PIX objects are not managed memory — failure to handle them with care in C# results in memory leaks
IronOCR:
- Images memory managed
- PDF & Broad image support:
- MultiFrame TIFF
- JPEG & JPEG2000
- GIF
- PNG
- System.Drawing Bitmaps, Stream, and Byte Array/Binary image Data (byte[]) are included for every file format
- IronSoftware.System.Drawing soon to replace System.Drawing reliance (allows universal Bitmap format)
Performance
Tesseract:
- Poorly documented settings must be fine-tuned to provide accurate
- Dependent on clean documents/pre-processed images
IronOCR:
- Zero configuration works accurately and at speed for most images
- Multithreading makes full use of multi-core processors
- Even low-resolution images generally work with a high degree of accuracy
- No Photoshop required
API
Tesseract:
Little to no support, not beginner friendly:
- Work with Interop layers — many found on GitHub are out of date with unresolved tickets, memory leaks, and console warnings
— May not support .NET Core or Standard - Work with the command line EXE — difficult to deploy and constantly interrupted by virus scanners and security policies
IronOCR:
- A managed and tested .NET Library for Tesseract called IronTesseract
- Fully documented with IntelliSense support
- Team of support engineers ready to assist
Languages
Tesseract:
- Only 100 languages
IronOCR:
- Over 127 built-in languages + custom language pack support
Conclusion
Tesseract is an excellent resource for C++ developers, but it is not a complete OCR library for .NET. Scanned or photographed images must be pre-processed so as to be orthogonal, standardized, high-resolution, and free of digital noise before Tesseract can accurately work with them.
In contrast, IronOCR can do this and more, with just a single line of code. IronOCR uses a very finely-tuned Tesseract for its internal OCR engine, built for C#, with a lot of performance improvements and features added as standard.