A large number of

image file formats An image file format is a file format for a digital image. There are many formats that can be used, such as JPEG, PNG, and GIF. Most formats up until 2022 were for storing 2D images, not 3D ones. The data stored in an image file format may be c ...

are available for storing graphical data, and, consequently, there are a number of issues associated with converting from one image format to another, most notably loss of image detail.

Software compatibility

Many image formats are native to one specific graphics application and are not offered as an export option in other software, due to proprietary considerations. An example of this is

Adobe Photoshop Adobe Photoshop is a raster graphics editor developed and published by Adobe Inc., Adobe for Microsoft Windows, Windows and macOS. It was created in 1987 by Thomas Knoll, Thomas and John Knoll. It is the most used tool for professional digital ...

's native PSD-format (Prevention of Significant Deterioration), which cannot be opened in less sophisticated programs for image viewing or editing, such as Microsoft Paint. Most image editing software is capable of importing and exporting in a variety of formats though, and a number of dedicated image converters exist.

Loss due to compression

Besides uncompressed formats and

lossless compression Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statisti ...

formats that can usually be interconverted without any loss of detail, there are compressed formats such as

JPEG JPEG ( , short for Joint Photographic Experts Group and sometimes retroactively referred to as JPEG 1) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degr ...

, which lose detail on nearly every compress. While a conversion from a compressed to an uncompressed format is in general without loss, this is not true the other way around. Even a compressed-uncompressed-compressed round trip without any image manipulation may incur some loss of detail.

Loss due to format change

Like any resampling operation, changing image size and bit depth are lossy in all cases of

downsampling In digital signal processing, downsampling, compression, and decimation are terms associated with the process of ''resampling'' in a multi-rate digital signal processing system. Both ''downsampling'' and ''decimation'' can be synonymous with ''co ...

, such as 30-bit to 24-bit or 24-bit to 8-bit palette-based images. While increasing bit depth is usually lossless, increasing image size can introduce

aliasing In signal processing and related disciplines, aliasing is a phenomenon that a reconstructed signal from samples of the original signal contains low frequency components that are not present in the original one. This is caused when, in the ori ...

or other undesired artifacts.

RAW images

More expensive

digital cameras A digital camera, also called a digicam, is a camera that captures photographs in digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film or film stock. Digital cameras are now ...

usually offer the option to shoot in

Raw image format A camera raw image file contains unprocessed or minimally processed data from the image sensor of either a digital camera, a motion picture film scanner, or other image scanner. Raw files are so named because they are not yet processed, ...

. RAW is not a standardized format, in fact, RAW-formats even differ between camera models from the same vendor. Data in a RAW-file is structured according to the

Bayer filter A Bayer filter mosaic is a color filter array (CFA) for arranging RGB color model, RGB color filters on a square grid of photosensors. Its particular arrangement of color filters is used in most single-chip digital image sensors used in digit ...

's pattern in cameras that use a single

image sensor An image sensor or imager is a sensor that detects and conveys information used to form an image. It does so by converting the variable attenuation of light waves (as they refraction, pass through or reflection (physics), reflect off objects) into s ...

. Debayering, the process of obtaining bitmap data from a RAW-image is always a lossy operation. In addition, some downsampling is always performed, again reducing image information.

Software compatibility

Loss due to compression

Loss due to format change

RAW images

See also