The World of Contrasts

Topics Covered: What is Contrast? Contrast Ratio and Dynamic Range Contrast is what makes photography interesting – Conrad Hall “You like boundaries and edges, don’t you?” quizzed Dr. Optoglass. He can see through me, thought Bob. “They are interesting, I guess.” “More than that, my dear boy. They are absolutely necessary. Did you wonder why […]

Professor Sampler’s Notes: Aliasing

Topics Covered: The two definitions of aliasing The need for an anti-aliasing filter Undersampling and oversampling So far as the theories of mathematics are about reality, they are not certain; so far as they are certain, they are not about reality – Einstein An alias is a duplicate. It’s like a signal has a split […]

Professor Sampler’s Notes: Interpolation

Topics Covered: The Interpolation Formula Upsampling and Downsampling The interpolation error Filters – active and passive filters Low-pass, high-pass and band-pass filters When you can measure what you are talking about and express it in numbers, you know something about it – Kelvin What makes interpolation possible? Mathematics. I know you were hoping for a […]

Professor Sampler’s Notes: Reconstruction

Topics Covered: Reconstruction Definition of Interpolation The Nyquist-Raabe criterion Definition of Extrapolation The boxcar, rectangular and sinc functions One typical reconstruction methodology I have had my results for a long time: but I do not yet know how I am to arrive at them – Carl Gauss Can we bring back our T-Rex? That cute Veggie-saur […]

Professor Sampler’s Notes: The Shannon-Nyquist Sampling Theorem Part III

Topics Covered: The Shannon-Nyquist Sampling Theorem The Nyquist rate A bandlimited signal vs a timelimited signal Amplitude The frequency spectrum and the bandwidth Willingly would I burn to death like Phaeton, were this the price for reaching the sun and learning its shape, its size and its substance – Eudoxus of Cnidus Fantastic! According to […]

Professor Sampler’s Notes: The Shannon-Nyquist Sampling Theorem Part II

Topics Covered: Time-domain to frequency-domain – a different kind of thinking Mighty is geometry; joined with art, resistless – Euripides I realized one fatal flaw in my reasoning. I realized, even if took a million samples, I might miss a house or more if they happened to fall between two samples. How do I get […]

Professor Sampler’s Notes: The Shannon-Nyquist Sampling Theorem Part I

Topics Covered: Practical sampling There are things which seem incredible to most men who have not studied mathematics – Archimedes The curious case of Postman Hertz Postman Hertz is Wolfcrow’s only postman, and has never missed a day’s work in twenty years. “He’s leica machine,” people say. What’s his secret? Exercise. On an average day, […]