The Bayer Lattice: Understanding the Geometry of Digital Sensors
Most people assume a digital sensor has pixels that can see every color. In reality, a sensor is color-blind. It only measures the intensity of light. The "color" is created through an ingenious geometric mosaic called the Bayer Filter.
The RGBG Pattern
A Bayer filter is a grid of color filters placed over the pixels. It follows a specific "RGBG" pattern:
- 50% Green: Because the human eye is most sensitive to green light.
- 25% Red: To capture the long-wavelength spectrum.
- 25% Blue: To capture the short-wavelength spectrum.
The Demosaicing Algorithm
Since every pixel only sees ONE color, the computer must "guess" the other two. This process is called Demosaicing.
- The engine looks at a Red pixel.
- It looks at the neighboring Green and Blue pixels.
- It uses a mathematical interpolation (like Bi-cubic or AHD) to calculate the most likely RGB value for that specific point.
Moiré and Anti-Aliasing
When a Bayer pattern tries to photograph a repetitive fine detail (like a pinstripe suit), the overlapping grids can create a wavy distortion called Moiré. High-end cameras use an "Optical Low-Pass Filter" (OLPF) to slightly blur the image at the pixel level to prevent this, illustrating the delicate balance between sharpness and accuracy.
Our local-first synthesizer respects these sensor-level geometries when converting RAW-adjacent formats like TIFF or high-fidelity JPEGs.