JPEG (full name is Joint Photographic Experts Group) is a common image format. It was developed by the Joint Photographic Experts Group and named "ISO 10918-1". JPEG is just a Just a common name.
The compression technology of the JPEG file extension is very advanced. It removes redundant images and color data, obtains extremely high compression rates, and displays very rich and vivid images. In other words, That is, you can get better image quality with the least disk space.
At the same time, JPEG is also a very flexible format that has the function of adjusting image quality, allowing you to compress this kind of file with different compression ratios. For example, we can compress a BMP bitmap file of up to 1.37MB to 20.3KB. Of course we can find a balance between image quality and file size.
JPEG is the abbreviation of Joint Photographic Experts Group (Joint Photographic Experts Group). The file suffix is ".jpg" or ".jpeg". It is the most commonly used image file format. It is developed by a software development consortium. Tissue format is a lossy compression format that can compress images into a small storage space. Repeated or unimportant data in the image will be lost, thus easily causing damage to the image data. In particular, using an excessively high compression ratio will significantly reduce the quality of the image restored after final decompression. If you pursue high-quality images, it is not advisable to use an excessively high compression ratio.
But JPEG compression technology is very advanced. It uses lossy compression to remove redundant image data, and can display very rich and vivid images while obtaining extremely high compression rates. In other words, it can be used Minimal disk space for better image quality. Moreover, JPEG is a very flexible format that has the function of adjusting image quality, allows files to be compressed with different compression ratios, and supports multiple compression levels. The compression ratio is usually between 10:1 and 40:1. The compression ratio The larger the compression ratio, the lower the quality; conversely, the smaller the compression ratio, the better the quality.
For example, a 1.37Mb BMP bitmap file can be compressed to 20.3KB. Of course, you can also find a balance between image quality and file size. The JPEG format mainly compresses high-frequency information and retains color information well. It is suitable for use on the Internet, can reduce image transmission time, can support 24-bit true color, and is also commonly used in images that require continuous tone.
JPEG format is currently the most popular image format on the Internet. It is a format that can compress files to the smallest format. When stored in JPEG format in Photoshop software, it provides 11 levels of compression, represented by levels 0-10. . Among them, level 0 has the highest compression ratio and the worst image quality. Even when saving at level 10 quality with virtually no loss of detail, the compression ratio can reach 5:1. When saving in BMP format, a 4.28MB image file is obtained. When saving in JPG format, the file is only 178KB, with a compression ratio of 24:1. After many comparisons, using level 8 compression is the best ratio for both storage space and image quality. The advantages of PG files are small size and good compatibility.
The above is the detailed content of What does jpeg mean?. For more information, please follow other related articles on the PHP Chinese website!