A massive number of image file formats 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

Adobe Photoshop is a graphics editing program developed and published by Adobe Systems Incorporated.Adobe's 2003 "Creative Suite" rebranding led to Adobe Photoshop 8's renaming to Adobe Photoshop CS. Thus, Adobe Photoshop CS5 is the 12th major release of Adobe Photoshop...

's native PSD-format, which cannot be opened in less sophisticated programs for image viewing or editing, such as Microsoft Paint

Microsoft Paint

Paint is a simple graphics painting program that has been included with all versions of Microsoft Windows. It is often referred to as MS Paint or 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 formats that can usually be interconverted without any loss of detail, there are compressed formats such as JPEG

JPEG

In computing, JPEG . The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality....

, 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 encur some loss of detail.

Loss due to format change

Like any resampling

Resampling

Resampling may refer to:* Resampling , several related audio processes* Resampling , resampling methods in statistics* Resampling , scaling of bitmap images* Sample rate conversion-See also:* Downsampling* Upsampling...

 operation, changing image size and bit depth

Bit depth

Bit depth may refer to:* For bit depth in graphics, see color depth* For bit depth in audio, see audio bit depth* For bit depth in drilling for petroleum, see drilling rig...

 are lossy in all cases of downsampling

Downsampling

In signal processing, downsampling is the process of reducing the sampling rate of a signal. This is usually done to reduce the data rate or the size of the data....

, such as 30-bit to 24-bit or 24-bit to 8-bit palette

Palette (computing)

In computer graphics, a palette is either a given, finite set of colors for the management of digital images , or a small on-screen graphical element for choosing from a limited set of choices, not necessarily colors .Depending on the context In computer graphics, a palette is either a given,...

-based images. While increasing bit depth is usually lossless, increasing image size can introduce aliasing

Aliasing

In signal processing and related disciplines, aliasing refers to an effect that causes different signals to become indistinguishable when sampled...

 or other undesired artifacts.

RAW images

More expensive digital cameras usually offer the option to shoot in Raw image format

RAW image format

A camera raw image file contains minimally processed data from the image sensor of either a digital camera, image scanner, or motion picture film scanner. Raw files are so named because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor...

. It should be made clear, that 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

Bayer filter

A Bayer filter mosaic is a color filter array for arranging 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 digital cameras, camcorders, and scanners to create a color image...

's pattern in cameras that use a single image sensor

Image sensor

An image sensor is a device that converts an optical image into an electronic signal. It is used mostly in digital cameras and other imaging devices...

. '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.

See also

• Comparison of graphics file formats
  Comparison of graphics file formats
  -General:Ownership of the format and related information.-Technical details:...
  
  
• Image file formats
  Image file formats
  Image file formats are standardized means of organizing and storing digital images. Image files are composed of either pixels, vector data, or a combination of the two. Whatever the format, the files are rasterized to pixels when displayed on most graphic displays...
  
  
• Image organizer
  Image organizer
  An image organizer or image management application is application software focused on organizing digital images. Image organizers represent one kind of desktop organizer software applications.- Common image organizers features :...
  
  
• Image viewer
  Image viewer
  An image viewer or image browser is a computer program that can display stored graphical image; it can often handle various graphics file formats...