# What is an analysis dictionary or operator in compressive sensing?

I am doing research on compressive sensing. I am new in this field. I read several papers regarding analysis dictionaries.

Here are some papers that I have read so far:

https://www.hindawi.com/journals/tswj/2014/852978/

https://www.matec-conferences.org/articles/matecconf/pdf/2018/18/matecconf_ijcaet-isampe2018_01061.pdf

https://ieeexplore.ieee.org/abstract/document/7374920

What I do not understand is if I have

$$Ω ∈ \mathbb{R}^{P\times M}$$ where $$x$$ is the raw signal, $$x ∈ \mathbb{R}^{M \times 1}$$

• What is an analysis dictionary (AD,) and an example of an analysis dictionary?
• How can we obtain $$AD ∈ \mathbb{R}^{P \times 1}$$
• It seems to me that the papers you have read so far are not very authoritative. Why did you chose them? – Laurent Duval Apr 16 at 20:34
• I read IEEE proceeding that stated Greedy Analysis Pursuit has better performance rather than any methods in Greedy class, therefore I am interested in GAP – AmandaKamphoff Apr 21 at 6:06