Most of the images that you see on the computer screen are all raster graphics. The pictures that you see on the web and the photos that you import are all those raster graphics from your digital camera. They are composed of grid of pixels, which are usually referred to as a bitmap.
The larger the image, the more disk space it will take the image file . For example, a 640 x 480 image can store approximately 307,200 pixels of information, while a 3072 x 2048 image (which is photographed with a 6.3 megapixel digital camera) stores approximately 6,291,456 pixels of information. is.
Some raster graphics have to store a lot of information, large bitmaps require large file sizes. The good thing in this is that there are many such image compression algorithms that can be used to reduce these file sizes. JPEG and GIF are the most common compressed image formats on the web, but there are many different types of image compression available.
Raster graphics are typically scaled down without loss of quality, but enlarging a bitmap image makes the image appear more blocky and “pixelated”. This is why, vector graphics are often used for some images, such as company logos, which are scaled to different sizes.