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Compression 101
What is compression?
• Compression – Refers to reducing the quantity of data used to represent video images with the goal of retaining as much of the original’s quality as possible. • On the next few slides we will go over the different types of compression that are more prevalent in the CCTV industry.
Spatial vs. Temporal compression
• Compression techniques revolve around two basic concepts: Spatial compression and Temporal compression.
• Spatial Compression – Used on a single image as a completely independent entity with no relation to other frames, and removes data unuseful for describing the image. (JPEG)
• Temporal Compression
– Focuses on storing the changes between subsequent frames rather than the entire frame in isolation. If very little changes between subsequent frames then very little storage space is consumed. (MPEG)
JPEG Compression
• JPEG – An extremely popular spatial compression algorithm focusing on individual photographs or very low framerate video.
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