Editing Mixed raster content (section)

{{Short description|Image compression method}}
'''Mixed raster content''' (MRC) is a method for compressing images that contain both binary-compressible text and continuous-tone components, using [[image segmentation]] methods to improve the level of compression and the quality of the rendered image.<ref name="deQueiroz1998">{{cite conference
|last1=de Queiroz |first1=Ricardo L.
|last2=Buckley |first2=Robert R.
|last3=Xu |first3=Ming
|date=1998-12-28 |df=dmy
|url=http://image.unb.br/queiroz/papers/ei99mrc.pdf
|title=Mixed Raster Content (MRC) Model for Compound Image Compression
|conference=Visual Communications and Image Processing '99
|conference-url=https://spie.org/Publications/Proceedings/Volume/3653
|series=SPIE Proceedings
|volume=3653
|doi=10.1117/12.334618
|isbn=978-0-8194-3124-0
|access-date=2023-11-23
}}</ref> By separating the image into components with different compressibility characteristics, the most efficient and accurate compression algorithm for each component can be applied.

MRC-compressed images are typically packaged into a hybrid file format such as [[DjVu]] and sometimes [[PDF]].<ref name=djvupdf>{{cite web |title=The MRC (Mixed Raster Content) Model and DjVu |url=http://www.djvu-soft.narod.ru/planetdjvu/the_mrc_mixed_raster_content_model_and_djvu.htm |website=PlanetDjVu |date=2003-06-10 |df=dmy}}</ref> This allows for multiple images, and the instructions to properly render and reassemble them, to be stored within a single file.

Some [[image scanner]]s optionally support MRC when scanning to PDF. A typical manual states that without MRC, the image is generated in a single process, with text and graphics not distinguished. With MRC, separate processes are used for text, graphics, and other elements, producing clearer graphics and sharper text, at the price of slightly slower processing. MRC is recommended to optimise the scanning of documents with harder-to-read text or lower-quality graphics.<ref>{{Cite book|url=https://www.xeroxscanners.com/downloads/Manuals/OT4/OneTouchGuide.EN.pdf|page=33|title=Visioneer OneTouch Scanning Guide|chapter=Text Formats|date=October 2019}}</ref> MRC can also reduce the size of the scanned file,<ref>{{Cite web |title=Image Compression |author= |website=Kofax |date= |access-date=11 March 2021 |url= https://docshield.kofax.com/PowerPDF/en_US/3.1.0_llem1i5177/help/Image_Compression.htm}}</ref> though higher compression using [[JBIG2]] can sometimes lead to character substitution errors in scanned documents.<ref name="WhitePaper">{{cite web |url=https://www.xerox.com/assets/pdf/scanning_compression_wp_en.pdf |title=Scanning and Compression White Paper |date=2013 |df=dmy |work=Xerox |archive-url=https://web.archive.org/web/20220121042519/https://www.xerox.com/assets/pdf/scanning_compression_wp_en.pdf  |archive-date=2022-01-21}}</ref>