Image file format
For example, graphically simple images (i.e. images with large continuous regions like line art or animation sequences) may be losslessly compressed into a GIF or PNG format and result in a smaller file size than a lossy JPEG format.
Lossless compression algorithms reduce file size while preserving a perfect copy of the original uncompressed image.
JPEG applies lossy compression to images, which can result in a significant reduction of the file size.
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.
[1][2] GIF is most suitable for storing graphics with few colors, such as simple diagrams, shapes, logos, and cartoon style images, as it uses LZW lossless compression, which is more effective when large areas have a single color, and less effective for photographic or dithered images.
The PNG (Portable Network Graphics) file format was created as a free, open-source alternative to GIF.
Compared to JPEG, PNG excels when the image has large, uniformly colored areas.
The Adam7 interlacing allows an early preview, even when only a small percentage of the image data has been transmitted — useful in online viewing applications like web browsers.
PNG can store gamma and chromaticity data, as well as ICC profiles, for accurate color matching on heterogeneous platforms.
In 2011,[3] Google added an "Extended File Format" allowing WebP support for animation, ICC profile, XMP and Exif metadata, and tiling.
The WebP container provides additional support for: Most typical raster formats cannot store HDR data (32 bit floating point values per pixel component), which is why some relatively old or complex formats are still predominant here, and worth mentioning separately.
RGBE is the format for HDR images originating from Radiance and also supported by Adobe Photoshop.
JPEG-HDR is a file format from Dolby Labs similar to RGBE encoding, standardized as JPEG XT Part 2.
JPEG XL is a royalty-free raster-graphics file format that supports both lossy and lossless compression.
It supports reversible recompression of existing JPEG files, as well as high-precision HDR (up to 32-bit floating point values per pixel component).
Some digital cameras can save images in TIFF format, using the LZW compression algorithm for lossless storage.
TIFF can handle device-specific color spaces, such as the CMYK defined by a particular set of printing press inks.
OCR (Optical Character Recognition) software packages commonly generate some form of TIFF image (often monochromatic) for scanned text pages.
Typically, BMP files are uncompressed, and therefore large and lossless; their advantage is their simple structure and wide acceptance in Windows programs.
It has been adopted to some extent in the areas of technical illustration and professional design, but has largely been superseded by formats such as SVG and DXF.
It is the de facto standard format for printed circuit board or PCB software.
