Constraints and Limitations¶
There are various factors, such as technology and cost, that limit the performance of OCR services. The system-level constraints are the most significant limitations that affect all sub-services. In addition to these system-level constraints, each sub-service also has its own independent limitations.
General Table OCR¶
Only images in PNG, JPG, JPEG, BMP, or TIFF format can be recognized.
No side of the image can be smaller than 15 or larger than 8,192 pixels.
The area to be recognized must occupy more than 80% of the image. When scanning a table, ensure that the entire table and its surrounding area are included in the image.
An image can be rotated to any angle.
Text in images with complex backgrounds (such as outdoor scenery or anti-counterfeit watermarks) or distorted table lines cannot be recognized.
English and Chinese are supported but support for traditional Chinese characters is limited.
General Text OCR¶
Only images in PNG, JPG, JPEG, BMP, GIF, TIFF, WebP, PCX, ICO, or PSD format can be recognized.
No side of the image can be smaller than 15 or larger than 8,192 pixels.
The area to be recognized must occupy more than 80% of the image. When scanning a table, ensure that all text and its surrounding area are included in the image.
An image can be rotated to any angle.
Text in images with complex backgrounds (such as outdoor scenery or anti-counterfeit watermarks) or distorted text cannot be recognized.
Supported languages: Chinese, English, some traditional Chinese, Malay, Ukrainian, Hindi, Russian, Vietnamese, Indonesian, Thai, Arabic, German, Latin, French, Italian, Spanish, Portuguese, Romanian, Polish Amharic, Japanese, Korean, Turkish, Norwegian, Danish, and Swedish.