Images

Image conversion

Image (spatial) sampling

• sampling is done in both space and colour
• brightness is sampled at points and stored in matrix of numbers
• each element is a pixel
• spacial resolution — size in pixels in each direction (e.g. 1920 x 1080, 1280 x 720)

Colour quantisation

• each pixel has a digital value represented in bits
• that’s analog brightness
• with 1 bit, not much is done — binary image
• with 8 bits, greyscale (0-255 per pixel, with white at 255)
• with 24 bits, colour (0-255, 0-255, 0-255 per each pixel in RGB)