Education Library

Frequently Asked Question

How do I determine the number of codeblocks per image?

Codeblocks are a result of the JPEG2000 compression process. Codeblocks are generated from the wavelet coefficient data after the pixel data has passed the wavelet filters. The number of codeblocks generated depends on the input resolution, codeblock size, number of transform levels, and the number of components.

Codeblock size can be changed with the CBSIZE firmware encode parameter.

Generally, standard definition (SD) resolutions do not require any particular codeblock size setting. For high definition (HD) resolutions, set the codeblock size to the maximum in order to keep the number of codeblocks generated below the maximum limit. (At present, the maximum number of codeblocks that the ADV2x2 can process is 610 per image, field, or frame.)

The technical note "How to estimate the number of codeblocks/image" explains how to estimate the number of codeblocks generated for a particular input resolution and CBSIZE setting.