Textract doesn't recognize some characters

This is a known limitation with Amazon Textract when processing certain characters or parts of text fields. There are several approaches you can take to address this issue:

1. Image Quality Optimization: Ensure your document images have high quality, good lighting, and minimal noise. Clear, well-contrasted images can significantly improve Textract's ability to recognize all characters accurately.

2. Preprocessing: Before sending images to Textract, apply image enhancement techniques such as noise reduction, contrast adjustment, or binarization to improve text clarity.

3. Post-processing: Implement logic in your code to handle missing characters. If you know the expected format or pattern of the text (like in your example), you can add validation to check if characters are missing and reconstruct the complete text.

4. Bounding Boxes: If possible, specify more precise regions of interest to help Textract focus on specific areas where text is present.

5. Alternative Extraction Methods: For critical data that Textract consistently misses, you might need to explore alternative OCR methods or services that can better handle your specific use case.

Unfortunately, Textract doesn't currently support direct training or fine-tuning by users to improve recognition of specific character patterns. However, AWS does use customer feedback to improve the service over time, so consider providing feedback about this specific issue.
Sources
Textract query result removing characters | AWS re:Post
Recognition of '1' from table filled in by hand | AWS re:Post
AWS Textract - Training | AWS re:Post
AWS Textract Missing Crucial Data in a Table | AWS re:Post