Dilation
Some images, such as store receipts, have very thin characters that may be damaged by automatic contrast corrections or binarization.
Aspose.OCR for Python via .NET provides a special processing filter called dilation that can increase the thickness of characters in an image by adding pixels to the edges of high-contrast objects, such as letters.
Dilation
To increase the thickness of characters in an image, run the image through dilate
processing filter.
# Instantiate Aspose.OCR API
api = AsposeOcr()
# Initialize image processing
filters = PreprocessingFilter()
filters.add(PreprocessingFilter.dilate())
# Add image to the recognition batch and apply processing filter
input = OcrInput(InputType.SINGLE_IMAGE, filters)
input.add("source.png")
# Save processed image to the "result" folder
ImageProcessing.save(input, "result")
# Recognize the image
result = api.recognize(input)
# Print recognition result
print(result[0].recognition_text)

Usage scenarios
Dilation is recommended for the following images:
- Receipts.
- Printouts with very thin font.