PaperScan allows image rotation at any angle besides the classic 90, 180 and 270 degrees rotation features.
Skew is an artifact that can occur in scanned images because of the camera being misaligned, imperfections in the scanning or surface, or simply because the paper was not placed completely flat when scanned. Deskew is the process of removing skew from images.
JBIG2 encoding is a a revolutionary breakthrough in captured document technology allowing scanned images to be compressed up to 10x smaller than with TIFF G4 and TIFF-based PDFs. It allows documents of any types to be viewed and manipulated efficiently over the Internet, and affords digital copiers/printers efficient network transmission of digitally copied documents. More on JBIG2
PDF/A is a file format for the long-term archiving of electronic documents. PDF/A is in fact a subset of PDF, obtained by leaving out PDF features not suited to long-term archiving.
PDF Searchable Image (often called PDF/OCR) is a PDF image-based document which, in addition to the visual representation of the original document (bitmapped layer), also contains a (hidden) text layer resulted from Optical Character Recognition (OCR) process so you can search for any word on any page of the PDF document.
PaperScan uses Tesseract OCR engine to create PDF/OCR files. Text can be viewed in PDF Viewer apps, such as Adobe Reader, PaperLight, etc.
You can remove the black dots (punch holes) from scanned document images after scanning punched documents.
PaperScan allows configurable punch holes removal .
TWAIN is an industry standard API for image acquisition, strongly oriented toward scanners. The TWAIN standard is maintained by the TWAIN Working Group. More on TWAIN
WIA (Microsoft Windows Image Acquisition) API is standardized for acquiring digital images from devices that are primarily used to capture still images and for managing these devices.WIA is a COM interface, very different from but overlapping with TWAIN. Compared to TWAIN it offers much better support for digital cameras, and much less sophisticated support for scanners. More on WIA