Image file formats
Including proprietary file formats, there are hundreds of image file types which can be divided into two main families: raster and vector. Raster image files contains the data for each pixel of the image, thus its size in correlated with the resolution, images size (number of pixels) and the color depth (bits per pixel). Vector images contains a geometric description of the image with vectors. Its size increases with the addition of more vectors.
Main raster formats
The BMP file format (Windows bitmap) is uncompressed, and therefore large and lossless. Its advantage is a simple structure and a wide acceptance in Windows programs.
JPEG (Joint Photographic Experts Group) is a lossy compression method. JPEG-compressed images are usually stored in the JFIF (JPEG File Interchange Format) file format. The JPEG/JFIF filename extension is JPG or JPEG. Applications can determine the degree of compression to apply, and the amount of compression affects the visual quality of the result. When not too great, the compression does not noticeably affect or detract from the image's quality, but JPEG files suffer generational degradation when repeatedly edited and saved.
JPEG 2000 is a compression standard enabling both lossless and lossy storage. The compression methods used are different from the ones in standard JFIF/JPEG. They improve quality and compression ratios, but also require more computational power to process.
The TIFF (Tagged Image File Format) format is a flexible format that normally saves eight bits or sixteen bits per color (red, green, blue) for 24-bit and 48-bit totals, respectively, usually using either the TIFF or TIF filename extension. The tagged structure was designed to be easily extendible, and many vendors have introduced proprietary tags resulting of a various number of specific readers.
GIF (Graphics Interchange Format) is in normal use limited to an 8-bit palette, or 256 colors (while 24-bit color depth is technically possible).GIF is most used for storing graphics with few colors, such as simple diagrams, shapes, logos, and cartoon style images.
The PNG (Portable Network Graphics) file format was created as a free, open-source alternative to GIF. The PNG file format supports eight-bit paletted images and 24-bit truecolor (16 million colors) or 48-bit truecolor with and without alpha channel. Compared to JPEG, PNG excels when the image has large, uniformly colored areas.
WebP is a new open image format created by Google that uses both lossless and lossy compression. Its main goal is to speed up page loading time by reducing file sizes.
Main vector formats
SVG (Scalable Vector Graphics) is an open standard created and developed by the World Wide Web Consortium to address the need for a versatile, scriptable and all-purpose vector format for the web.