What is CCITT Group 3 compression?
CCITT Group 3 is a lossless compressed data format for bi-level images. It is also known as T4, T. 4, Fax3, Group 3, G3, or ITU-T Fax Group 3. It is one of the formats used by fax machines. It is usually embedded in another image file format such as TIFF, but can be stored in a file by itself.
What is facsimile encoding in data compression?
The process by which fixed graphic images, such as printed text and pictures, are scanned, and the information converted into electrical signals that may be transmitted over a telecommunications system and used to create a copy of the original, or an image so produced.
What is a Group 4 TIFF?
TIFF Group 4 is a protocol used for sending fax documents through an ISDN line. In this group scan lines are encoded with reference to the previous one, creating better compression ratios. TIFF Group 4 2D – encoding is more than Group 3 encoding. Each scan line is compared to the scan line before it.
What is CCITT Group 4 encoding?
What is the CCITT Group 4 encoding? Suppose you have a monochrome (aka bitonal, aka black-and-white) bitmap image, i.e. a sequence of 0s and 1s, like the following crude drawing of the digit “3”: (Or more realistically, the data from a black-and-white scan of a piece of paper, being done inside a fax machine.) The goal is to compress it.
What is the difference between CCITT group4 and CCITT T6?
CCITT Group4 (G4FAX in our program) and CCITT T.6 are the same compression. CCITT Group 4 is a widely-used lossless compression algorithm for bitonal images. It is also known as T6, T.6, Fax4, G4, Group 4, or ITU-T Fax Group 4.
What is the CCITT algorithm?
The CCITT algorithm is an ad-hoc encoding scheme that is intended to achieve somewhat reasonable compression for typical documents. There are actually a few schemes, with names like “Group 3” (itself in multiple variants) and “Group 4”, but because Group 4 is what I encountered and care about right now, I’ll only focus on Group 4.
What is ccittfaxdecode and how do I use it?
This “CCITTFaxDecode” (see section 3.3.5 of the PDF reference) refers to the “CCITT facsimile (fax) encoding”, itself an informal name for “Recommendations T.4 and T.6 of the International Telecommunications Union (ITU)”. It also happens to be used as one of the possible compression options in TIFF files, but is not otherwise connected to TIFF.
https://www.youtube.com/watch?v=3KCu7_Twhxc