Images.html (1501B)
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3 <html><head><link rel="stylesheet" href="sitewide.css" type="text/css"><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><meta name="exporter-version" content="Evernote Mac 7.5.2 (457164)"/><meta name="altitude" content="-0.0002259806205984205"/><meta name="author" content="Alex Balgavy"/><meta name="created" content="2017-12-18 14:52:17 +0000"/><meta name="latitude" content="52.37359849166707"/><meta name="longitude" content="4.836369663993605"/><meta name="source" content="desktop.mac"/><meta name="updated" content="2017-12-19 19:37:35 +0000"/><title>Images</title></head><body><div><span style="font-weight: bold;">Image conversion</span></div><div>Image (spatial) sampling</div><ul><li>sampling is done in both space and colour </li><li>brightness is sampled at points and stored in matrix of numbers</li><li>each element is a pixel</li><li>spacial resolution — size in pixels in each direction (e.g. 1920 x 1080, 1280 x 720)</li></ul><div><br/></div><div>Colour quantisation</div><ul><li>each pixel has a digital value represented in bits</li><li>that’s analog brightness</li><li>with 1 bit, not much is done — binary image</li><li>with 8 bits, greyscale (0-255 per pixel, with white at 255)</li><li>with 24 bits, colour (0-255, 0-255, 0-255 per each pixel in RGB)</li></ul><div><br/></div></body></html>