That's my point. In order to analyze you need to preserve entire data. One system is the image acquisition. Another is the analysis, on more advanced systems. T

That's my point. In order to analyze you need to preserve entire data. One system is the image acquisition. Another is the analysis, on more advanced systems. The advanced system needs all data. Dismissing it at entry point defeats its purpose. No matter how you flip it, there are practical applications where huge matrices that have non-zero elements exists. Here is another example - cryptography analysis. Usually password length is small, usually below 1k characters. But if you increase the password length then simple old ciphers, like Vigenere, become harder to crack. Bump the key length to over 1 million bytes and suddenly your century old methods, like index of coincidence and Kasiski examination become a problem of having huge matrices to feed to analyzer. 1 million key length suddenly generates a matrix with 256M x 256M for analyzer. And all elements in that matrix are non zero.