ImageGear for C and C++ on Windows v19.10 - Updated
Enhance Resolution
User Guide > How to Work with... > OCR > How to... > Prepare the Input > Enhance Image Quality > Enhance Resolution

Resolution enhancement may be performed internally during image conversions. It involves a doubling of the resolution of a bi-tonal image resulting from an implicit secondary image conversion from grayscale or color. The doubling is performed on the basis of information available from the greater pixel depth in grayscale and color images. The resulting bi-tonal image exists in parallel with the original one, and is not available to the application.

The application has no control over when resolution doubling is done, only on whether and how it is done. The function IG_REC_res_enhancement_mode_set() accepts one of five settings from enumIGRecImgResEnhancement: