What are JPG, JPEG and PNG formats?

BMP format: the standard bitmap format under Windows system. If it is not compressed, the general image file will be larger. It is widely used in many softwares.

JPEG format: It is also one of the most widely used image formats. It uses a special lossy compression algorithm to delete the color of the image that is not easily perceived by human eyes, thus achieving a higher compression ratio (up to 2: 1 or even 40: 1). JPEG format is the most widely used format on the Internet because of its small file size and fast download speed!

GIF format: The biggest feature is that it can be not only a still picture, but also an animation, and it supports transparent background pictures. Suitable for a variety of operating systems, and the "volume" is very small. Many small animations on the Internet are in GIF format. However, its color gamut is not too wide, only supporting 256 colors.

PSD format: Photoshop's special image format, which can save the complete information of pictures, soil layers, passages and characters, and the image files are generally large.

PNG format: Similar to JPG format, there are many pictures in this format. The compression ratio is higher than GIF, which supports image transparency, and the transparency of the image can be adjusted through the Alpha channel. It is the source file of Fireworks, one of the Three Musketeers on the Web.

TIFF format: It is characterized by complex image format and a lot of stored information. The image format widely used in Mac improves the image quality because it stores a lot of subtle information of the image, which is very beneficial to the reproduction of the original. TIFF format is used for printing in many places.

TGA format: TGA has a simple structure and belongs to a general format of graphic image data, which has great influence in the multimedia field. Commonly used in film and television editing, such as 3DS MAX outputting TGA image sequence and importing AE for post-editing.

EPS format: Apple Mac users use it more. It is an ASCII file format described in PostScript language, which is mainly used for typesetting, printing and other output work. According to the general format, it has great influence in the field of multimedia and is often used in film and television editing. For example, 3DS MAX outputs TGA image sequence and imports AE for post-editing.

EPS format: Apple Mac users use it more. It is an ASCII file format described in PostScript language, which is mainly used for typesetting, printing and other output work.

Image format: BMP:Windows bitmap

Windows bitmaps can store a single raster image of any color depth (from black and white to 24-bit color). Windows bitmap file format is compatible with other Microsoft Windows programs. It does not support file compression, nor does it apply to web pages.

Generally speaking, the disadvantages of Windows bitmap file format outweigh the advantages. To ensure the quality of photo images, please use PNG files, JPEG files or TIFF files. BMP file is suitable for wallpaper in Windows.

Advantages:? BMP supports 1 bit to 24-bit color depth.

BMP format is widely compatible with existing Windows programs (especially older programs).

Disadvantages:? BMP does not support compression, which will make the file very large.

The Web browser does not support BMP files.

Pcx: computer brush

PC brush pictures (also known as Z-Soft bitmaps) store a single raster image at any color depth. Brush drawing is more widely used in early Windows programs and programs based on MS-DOS. Brush drawing is compatible with many newer programs. PCX pictures support RLE internal compression.

Advantages:? PCX is a standard format between many Windows-based programs and MS-DOS-based programs.

PCX supports internal compression.

Disadvantages:? Web browser does not support PCX.

PNG: portable network graphics

PNG pictures store a single raster image at any color depth. PNG is a platform-independent format.

Advantages:? PNG supports advanced lossless compression.

PNG supports alpha channel transparency.

PNG supports gamma correction.

PNG supports interleaving.

The latest web browsers support PNG.

Disadvantages:? Older browsers and programs may not support PNG files.

As an Internet file format, PNG provides less compression than JPEG lossy compression.

As an Internet file format, PNG does not support multi-image files or animation files. GIF format supports multi-image files and animation files.

JPEG: Joint Photographic Experts Group

JPEG pictures store a single raster image in 24-bit color. JPEG is a platform-independent format that supports the highest level of compression. However, this compression is lossy. Progressive JPEG files support interleaving.

You can increase or decrease the compression level of JPEG files. However, the file size is at the expense of image quality. The compression ratio can be as high as 100: 1. (JPEG format can easily compress files at the ratio of 10: 1 to 20: 1, and the image quality will not decrease. ) JPEG compression can handle realistic photographic works well. However, JPEG compression can not provide ideal results for simple works with few colors, strong contrast, solid color borders or large solid color areas. Sometimes the compression ratio is as low as 5: 1, which seriously loses the integrity of the picture. The reason for this loss is that JPEG compression scheme can compress similar tones well, but JPEG compression scheme can not deal with strong differences in brightness or solid color areas well.

Advantages:? Photographic works or realistic works support advanced compression.

The file size can be controlled by variable compression ratio.

Support interleaving (for progressive JPEG files).

JPEG widely supports Internet standards.

Disadvantages:? Lossy compression will reduce the quality of the original image data.

When you edit and resave a JPEG file, JPEG will mix the quality of the original picture data. This decline is cumulative.

JPEG is not suitable for simple pictures with few colors, similar colors in a large area or obvious brightness difference.

GIF: graphic interchange format

GIF pictures store single raster image data or multiple raster image data in 8-bit colors or 256 colors. GIF pictures support transparent, compressed, interlaced and multi-image pictures (animated GIF).

GIF transparency is not alpha channel transparency, so it cannot support translucent effect. GIF compression is LZW compression, and the compression ratio is about 3: 1. GIF89a version of GIF file specification supports dynamic GIF.

Advantages:? GIF widely supports Internet standards.

Support lossless compression and transparency.

Animation GIF is very popular, and it is easy to make with many GIF animation programs.

Disadvantages:? GIF only supports a 256-color palette, so detailed pictures and realistic photographic images will lose color information, but they look tonal.

In most cases, lossless compression is not as good as JPEG format or PNG format.

GIF supports limited transparency and has no translucent effect or fading effect (such as the effect provided by alpha channel transparency).

TIFF: tag image file format

TIFF stores a single raster image at any color depth. TIFF can be considered as the most widely supported graphic file format in the printing industry. TIFF supports optional compression and is not suitable for viewing in a Web browser.

TIFF format is an extensible format. This means that programmers can modify the original specification to add functionality or meet specific requirements. Modifying the specification may lead to incompatibility between different types of TIFF pictures.

Advantages:? TIFF is a widely supported format, especially between Macintosh computers and Windows-based computers.

Support optional compression.

Extensible format supports many optional functions.

Disadvantages:? The Web browser does not support TIFF.

Extensibility will lead to many different types of TIFF pictures. Not all TIFF files are compatible with all programs that support the basic TIFF standard.

Picture format: vector picture

DXF:AutoCAD graphic interchange file

DXF is a vector-based ASCII format used by Autodesk AutoCAD programs. AutoCAD can provide very detailed and fully extensible charts.

Advantages:? You can use AutoCAD to create very detailed and accurate charts and graphs.

AutoCAD files are very popular in architecture, design and sculpture industries.

Disadvantages:? The support of AutoCAD in Office is limited, and Office supports AutoCAD versions before R 12.

The learning curve of AutoCAD is steep. Please note that other graphics programs can also export DXF pictures.

Computer graphics metafile

CGM metafile can contain vector information and bitmap information. It is an international standardized file format used by many organizations and government agencies, including British Standards Institute (BSI), American National Standards Institute (ANSI) and US Department of Defense.

Advantages:? CGM is an international standard format.

CDR:CorelDRAW！

CorelDRAW！ Metafiles can contain vector information and bitmap information.

Advantages:? CDR is widely used in prepress industry and art design industry.

Disadvantages:? CDR has limited support in Office, and Office supports CorelDRAW! Version 6 and earlier.

WMF: window metafile

Windows metafile is a 16-bit Tu Tu metafile format, which can contain vector information and bitmap information. It is optimized for the Windows operating system.

Advantages:? WMF is a Windows standard format, which can be well used in office.

EPS: encapsulated PostScript

"Encapsulated PostScript" format is a special printer description language, which can describe vector information and bitmap information.

Advantages:? EPS can accurately render the effect on any PostScript printer.

EPS is an industry standard format.

Disadvantages:? The screen display may be inconsistent with the output display. The screen display may be low resolution, may be a different image, or just a placeholder image.

EPS file is used for output. They are not the most suitable formats for displaying information on the screen.

EMF: enhanced metafile

Enhanced metafile is a 32-bit format, which can contain vector information and bitmap information. This format is an improvement on the "Windows Metafile Format" and contains some extended functions, such as the following:

Built-in zoom information

Built-in instructions saved with the file

Improvements in color palette and device independence

The EMF format is extensible, which means that programmers can modify the original specification to add functions or meet specific requirements. This modification may lead to incompatibility between different types of EMF pictures.

Advantages:? Extensible file format

Compared with WMF, improved functions

Disadvantages:? Extensibility can produce many different types of EMF pictures, and not all EMF files are compatible with all programs that support EMF standards.

PICT: Macintosh pictures

PICT file is a 32-bit bitmap metafile format for Macintosh computers. PICT file uses RLE internal compression, and the effect is quite good. If QuickTime is installed, PICT files support JPEG compression (Macintosh only).

Advantages:? PICT is the best file format for Macintosh computer screen display.

PICT is the best output format when outputting from Macintosh computer to non-PostScript printer.

Disadvantages:? Fonts may not display correctly when moving between platforms.

QuickTime must be installed to view some PICT files correctly.