Digital images processed by computers are mainly divided into two categories: vector graphics and bitmap images.

Vector based graphics (Vector based graphics) is also called geometric figures or vector diagrams, referred to as graphics (Gmphics), refers to a variety of graphics drawn by a set of drawing instructions. These instructions include the size and shape of each line, arc, circle, and rectangle describing an image. To realize an image, as long as the relevant software is executed to read these instructions, the shape and color of the drawn graphics can be displayed on the screen. Because the image generated by vector graphics is composed of straight lines, circles and arcs, it does not have the drawing effect of bitmap mode. Vector graphics are often used for line drawing, such as newspaper layout, architectural design drawing, CAD, etc. Currently, many Windows operating systems have drawing programs to draw and display shapes. The main advantage of vector graphics is that you can control each part of the picture separately. Moving each part on the screen and compressing, enlarging, rotating, and distorting it will not destroy the picture. The main disadvantage of vector graphics is that as the complexity of the image increases, the time spent on computer coloring increases greatly.

Bitmap image (Bitmap hnage) is also called bitmap image, bitmap image or point bitmap, referred to as image (hnage). The image consists of a set of computer memory bits that define the brightness and color of each pixel in the image. Images generated using bitmaps are usually more detailed, and the layers and colors are richer and truer. Bitmaps can be generated with drawing software, or two-dimensional pictures can be scanned with color scanners, or digital images can be obtained with cameras and frame capture devices. Displaying bitmap images is much faster than displaying vector graphics images. The bitmap can be directly displayed in the memory using the image acquisition device, which saves the time required for generating vector images. But the disk space required by the bitmap is larger than the vector graphics.
The digitized image obtained by scanning is a kind of raster image. When storing it, it needs to be stored in a certain file format. Almost every image processing software has its own way of processing images, storing images in different formats. In order to use existing image files, or use images in different software, it is necessary to pay attention to the difference in image format, and if necessary, convert the image format.