What is a bitmap file

A bitmap file, also known as a bitmap or raster image, is an image file represented by an array of pixels. The pixels of the bitmap are assigned specific positions and color values. The color information of each pixel is represented by an RGB combination or grayscale value; and according to the bit depth, the bitmap can be divided into 1, 4, 8, 16, 24 and 32-bit images, etc., the higher the number, the richer the colors.

#The operating environment of this article: Windows 7 system, Dell G3 computer.

Bitmap (English: Bitmap, called bitmap in Taiwan), also known as raster graphics, is an image represented by a pixel array (Pixel-array/Dot-matrix lattice).

The pixels of a bitmap are assigned a specific position and color value. The color information of each pixel is represented by an RGB combination or grayscale value.

According to the bit depth, bitmaps can be divided into 1, 4, 8, 16, 24 and 32-bit images. The more bits of information used per pixel, the more colors are available, the more realistic the color performance, and the corresponding larger amount of data. For example, a pixel bitmap with a bit depth of 1 has only two possible values ​​(black and white), so it is also called a binary bitmap. An image with a bit depth of 8 has 2 to the power of 8 (or 256) possible values. A grayscale image with a bit depth of 8 has 256 possible gray values.

Most bitmap file formats are stored in lossy compression to save storage space.

Common bitmap file extensions: .BMP, .TIF, .JPG, .GIF and .PNG.

RGB images consist of three color channels. Each channel in an 8-bit/channel RGB image has 256 possible values, which means the image has over 16 million possible color values. RGB images with 8 bits per channel (bpc) are sometimes referred to as 24-bit images (8 bits x 3 channels = 24 bits of data/pixel). [2] Bitmaps represented using 24-bit RGB combined data bits are usually called true color bitmaps.

BMP files are a method of exchanging and storing data developed by Microsoft. All versions of Windows support BMP format files. Windows provides a fast and convenient way to store and compress BMP files. The disadvantage of the BMP format is that it takes up a lot of storage space and the file size is too large.

A bitmap usually represented by 24-bit RGB combined data bits is called a true color bitmap. Simply put, a bitmap is a pattern composed of countless color points. When you zoom in infinitely, you will see pixel color blocks one by one, and the effect will be distorted.

Extended information

Comparison between bitmap and vector graphics:

Other image file types include vector graphics files and 3D image files.

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