A Pixel is one of the many tiny dots that form an image in the computer’s memory, pixels may have different shapes, intensities, and colors (RGB or CMYK model). The more pixels used to represent an image, the finer will be the result.
A Megapixel is one million pixels, is used for numbering the pixels in an image, but also to express the number of digital elements of digital camera sensors or the number of digital elements of digital displays.
Also, a digital camera with an array of 2048 x 1536 sensor elements will be 3,1 Megapixels (2048 × 1536 = 3,145,728).
If our computer display is set to a resolution of 1024 x 768 pixels, this means that the whole image viewed on the display contain a total of 786.432 pixels, and to view a larger image in the real size, we must scroll through the image.
Bits Per Pixel (BPP) is the number of distinct colors that can be represented by a pixel. The more bits per pixel, the more colors a pixel can show and the color transition in an image will be smoother.
– 4bpp = 16 colours
– 8bpp = 256 colours
– 16bpp = 65.536 colours (Highcolour)
– 24bpp = 16.777.216 colours (Truecolor)
Different graphical file types support different bits per pixel. For example, the TIFF format can support 48-bit pixels, however this bit-depth is not supported by computer displays, these files are used for professional scanning and printing applications, and can be viewed at 24-bit depth on computer displays. On the other side, the GIF image format supports only 8-bit depth, meaning that in the whole image you can see only 256 distinct colours. The most common image file format is JPEG.