What is the difference between bmp and JPG

The main differences between BMP and JPG are:

1, bmp is to save the image by recording each pixel grid, which takes up more memory space, but the image is not easily distorted.

2, jpg is a lossy compression format, occupies a relatively small area, but repeatedly saved, it will be repeatedly compressed, which will lead to distortion.

BMP (full name Bitmap) is the standard image file format in the Windows operating system, can be divided into two categories: device vector-related bitmap (DDB) and device vectorless off bitmap (DIB), the use of a very wide. It uses a bit-mapped storage format and does not use any compression other than the optional image depth, so the space occupied by the BMP file is large.

The image depth of BMP file can be selected lbit, 4bit, 8bit and 24bit.When BMP file stores data, the image is scanned in the order from left to right and from bottom to top. Since the BMP file format is a standard for exchanging graph-related data in the Windows environment, graphic image software running in the Windows environment supports the BMP image format.

JPEG is the abbreviation of Joint Photographic Experts Group (Joint Photographic Experts Group), the file dropout name ".jpg" or ".jpeg", is the most commonly used image file format.

Developed by a software development consortium, it is a lossy compression format that compresses images into a small amount of storage space, where duplicate or unimportant information in the image is lost, thus making it easy to damage image data.

In particular, using too high a compression ratio will significantly reduce the quality of the image recovered after final decompression, so if you are pursuing high-quality images, it is not advisable to use too high a compression ratio.

For example, a 1.37Mb BMP bitmap file can be compressed to 20.3KB, and of course a balance can be found between image quality and file size.JPEG format compresses mainly high-frequency information, retains color information better, and is suitable for use on the Internet to reduce the transmission time of the image, supports 24-bit true-color, and is also commonly used for images that require continuous color tones. It can support 24bit true color, and is also commonly used for images that require continuous color tones.

Expanded Information:

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BMP Format Composition

The typical BMP image file consists of four parts:

1: the bitmap header file data structure, which contains information such as the type of the BMP image file, the content of the display, and so on;

2: the bitmap information data structure, which contains the width, height, compression method, and definition of color, and so on of the BMP image. and compression method, as well as defining the color and other information;

3: color palette, this part is optional, some bitmaps need color palette, some bitmaps, such as true-color images (24-bit BMP) do not need color palette;

4: bitmap data, this part of the content according to the number of bits used in BMP bitmaps are different, in the 24-bit image directly using RGB, while the others less than 24 bits use the color index value in the palette.

Types of JPG Format

JPEG2000, as an upgraded version of JPEG, has a compression rate about 30% higher than that of JPEG, and supports both lossy and lossless compression.The JPEG2000 format has an extremely important feature in that it enables progressive transmission, i.e., transmitting the contours of the image first, then transmitting the data gradually to improve the quality of the image, allowing the image to go from a hazy to a clear display. image from hazy to clear display.

In addition, JPEG2000 supports the so-called "region of interest" feature, which allows you to specify the compression quality of the region of interest on the image, and also to select a specified portion to decompress first.

JPEG2000 can be used in traditional JPEG markets, such as scanners and digital cameras, as well as in newer applications, such as network transmission and wireless communications.

References:

. p>Baidu Encyclopedia-BMP

References:

Baidu Encyclopedia-JPEG