Megapixels, size and formats

摘要

Moving to digital photography from film there is a new vocabulary to learn, with terms like megapixels, JPEG, TIFF, compression and 8-bit. What do these terms mean and how do they relate to each other ? Digital images are made up of huge numbers of dots, known as pixels. The part of the digital camera which creates the image is known as the sensor. Cameras vary in the number of pixels in their sensors and the overall size of the sensor itself. A key point is that the arrangement of pixels in the image created by the camera is always a rectangular grid. If the sensor has a different arrangement, various calculations are done by the camera software to create the standardised rectangular grid. Saying this in another way, whatever the type of sensor in the camera the final image is always a rectangular grid of pixels.