Difference Between Bitmap and Vector

Bitmap vs Vector
 

In computer graphics, Bitmap and Vector graphics are two file formats that are used to store digital images. The bitmap format uses an array of bits with reference to the position of the each bit; that is, a map of bits to represent the image. Bitmap belongs to raster graphics image format class. The vector graphics format uses basic geometric shapes such as points, lines, curves, and polygons to represent the image.

More about Bitmap

A mapping of bits representing the image as an array is known as a bitmap. Similarly, a mapping of pixels is called as a pixmap. From a certain perspective, it can be stated that a mapping with 1- bit per pixel as a bitmap and a mapping with many – bits per pixel as a pix map. In uncompressed formats of bitmaps, image pixels are stored in different color depths within the range from 1, 2, 4, 8, 16, 24, and 32 pixels. Color depths lower than 8-bits are used to store grayscale color or indexed color scales.

Bitmap images are saved with the extension .bmp. Minimum file size of a bitmap image can be obtained by size = width • height • n/8, where height and width are given in pixels, and n is the color depth and size is file size in bytes. With n-bit color depth, a bitmap may incorporate 2n colors in the image. Upon magnification, the pixels consisting bitmap image become visible as with any raster graphics image such as TIFF or JPEG, making the image unclear.

More about Vector Graphics

The Vector graphics use the basic geometric figures and shapes to represent an image, where all the components are represented with mathematical expressions. The image is generated using the paths or strokes (vectors representing a shape or a geometric figure) passing through a grid of control points embedded in the work plan for the image with definite positional coordinates. Image contains instructions to generate the strokes with given shape, color and thickness. This information is in the structure of the file which tells the computer to draw the image; therefore, any change in these parameters does not affect the file size significantly. More importantly, upon magnification, unlike the raster graphics the quality of the image does not significantly change. This is because the vector graphics generate the image based on structural details rather than positional details.

Vector graphics are used in modern 2D and 3D imaging applications. High quality typography is also based on vector graphics. Most of the modern printers and displays are still raster devices; therefore, in displaying or printing, vector graphics has to be converted into raster images and is relatively an easy process. In the process, the file size of the image barely changes. But converting raster images to vector graphics is an extremely difficult process because of the complex shapes and figures in raster image, which need to be represented by mathematical expressions. Devices like cameras and scanners work based on raster graphics rather than on vector graphics. It is impractical to convert such images to vector graphics because of the complex nature of the conversion required.

Vector graphics files use the file types SVG and CGM.