Categories
Driving Miss Digital

The Sine Grating

Topics Covered: On the nature of Edges and Boundaries The Sine Grating The eye altering, alters all – William Blake There are no sharp edges in the absolute sense. If you zoom in close, even the sharpest edge will become smooth at some point. If you zoom out far enough, even the smoothest of edges […]

Categories
Driving Miss Digital

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 […]

Categories
Driving Miss Digital

Image Resolution

Topics Covered: Resolution and Detail The Optotype The Resolution of the Human Eye at 20/20 vision “There are people who have been tested at 20/8 vision, and 20/12 vision is quite common. But that’s nothing compared to hawks – they supposedly have 20/2 vision.” Another long intake of breath by Dr. Optoglass. He was like […]

Categories
Driving Miss Digital

The Challenge

If there was one thing that could take Bob’s mind off Cathy, it was a busy shoot. It was a Wolfcrow town production, and Mayor Bayer was keen to have his town shown in the best possible light. Bob’s dad was in charge of this production. His dad looked like a superhero with a bazooka […]

Categories
Driving Miss Digital

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 […]

Categories
Driving Miss Digital

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 […]

Categories
Driving Miss Digital

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 […]

Categories
Driving Miss Digital

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 […]

Categories
Driving Miss Digital

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 […]

Categories
Driving Miss Digital

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, […]