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Digital image editing is the process of altering digital images, whether they be digital photographs or other types of digitally represented images. Specialised software programs called vector graphics editors or raster graphics editors are the primary tools with which a user may manipulate, enhance, and transform images. These editors are capable of editing images in many diverse ways. A digital image is a representation of a two-dimensional image as a finite set of digital values, called picture elements or pixels. ...
It has been suggested that Digital photography/Temp be merged into this article or section. ...
In common usage, an image (from Latin imago) or picture is an artifact that reproduces the likeness of some subject—usually a physical object or a person. ...
Computer software (or simply software) refers to one or more computer programs and data held in the storage of a computer for some purpose. ...
A screenshot of the xfig vector graphics editor A screenshot of the modern vector graphics editor Xara Xtreme A vector graphics editor is a computer program that allows users to compose and edit vector graphics images interactively on the computer screen (compare with MetaPost) and save them in one of...
A screenshot from the KDE raster graphics editor KolourPaint A screenshot from the GIMP raster graphics editor A raster graphics editor is a computer program that allows users to paint and edit pictures interactively on the computer screen and save them in one of many popular bitmap or raster formats...
Digital imaging is closely associated with digital photography and is used extensively in the fields of digital art, science, medicine, and forensics. Computer-generated image created by Gilles Tran using POV-Ray 3. ...
Part of a scientific laboratory at the University of Cologne. ...
This article is about the field and science of medical practice and health care. ...
Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. ...
Basics of image editing Raster images are stored in a computer in the form of a grid of picture elements called pixels. These pixels contain the image's color and brightness information. Image editors can change the pixels to enhance the image in many ways. The pixels can be changed as a group, or individually, by the sophisticated algorithms within the image editors. The domain of this article primarily refers to bitmap graphics editors, which are often used to alter photographs and other raster graphics. However, vector-based software, such as Adobe Illustrator can be used to alter or construct other types of image, namely ones based upon vectors. Adobe Photoshop is the most common application commercialy used for digitally manipulating images. Suppose the smiley face in the top left corner is an RGB bitmap image. ...
A pixel (a contraction of picture element) is one of the many tiny dots that make up the representation of a picture in a computers memory. ...
Flowcharts are often used to represent algorithms. ...
Adobe Illustrator is a vector-based drawing program developed and marketed by Adobe Systems. ...
Example showing effect of vector graphics on ppm scale: (a) original vector-based illustration; (b) illustration magnified 8x as a vector image; (c) illustration magnified 8x as a raster image. ...
Adobe Photoshop, or simply Photoshop, is a graphics editor developed and published by Adobe Systems. ...
Image editing programs Because of the popularity of digital cameras, image editing programs are readily available. Minimal programs, that perform such operations as rotating and cropping are often provided within the digital camera itself, while others are returned to the user on a compact disc (CD) when images are processed at a discount store. The more powerful programs contain functionality to perform a large variety of advanced image manipulations. Popular raster-based digital image editors include Adobe Photoshop, Corel Photo-Paint, Paint Shop Pro, Visualizer Photo Studio, Pixel image editor, PixBuilder Photo Editor, Fo2Pix ArtMaster, the GIMP, and Paint.net. For more, including free programs, see: List of raster graphics editors. A SiPix digital camera next to a matchbox to show scale. ...
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A SiPix digital camera next to a matchbox to show scale. ...
This article or section does not cite its references or sources. ...
Adobe Photoshop, or simply Photoshop, is a graphics editor developed and published by Adobe Systems. ...
PHOTO-PAINT icon Corel PHOTO-PAINT is a bitmap graphics editor sold by Corel, a software company with headquarters in Canada. ...
Paint Shop Pro (PSP) is a bitmap graphics editor and vector graphics editor for computers running the Microsoft Windows operating system that was originally published by Minneapolis-based Jasc Software. ...
Pixel image editor (formerly known as Pixel32) is an Adobe Photoshop-like image editor written by Pavel Kanzelsberger. ...
Look up gimp in Wiktionary, the free dictionary. ...
Paint. ...
It has been suggested that this article or section be merged into Comparison of raster graphics editors. ...
Digital data compression Many image file formats use data compression to reduce file size and save storage space. Digital compression of images may take place in the camera, or can be done in the computer with the image editor. When images are stored in JPEG format, compression has already taken place. Both cameras and computer programs allow the user to set the level of compression. In computer science and information theory, data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than an unencoded representation would use through use of specific encoding schemes. ...
In computing, JPEG(pronounced JAY-peg; IPA: ) is a commonly used standard method of compression for photographic images and not for movie files for which MPEG compression is used. ...
Some compression algorithms are lossless, such as PNG, which means no image quality is lost when the file is saved. The JPEG compression algorithm uses a lossy format. The greater the compression, the lesser the quality. It utilizes the way the brain and eyes perceive color to make loss of detail less noticeable. Lossless data compression is a class of data compression algorithms that allow the original data to be reconstructed exactly from the compressed data. ...
A PNG image with an 8-bit transparency channel (top). ...
A lossy data compression method is one where compressing a file and then decompressing it retrieves a file that may well be different to the original, but is close enough to be useful in some way. ...
Image editor features Listed below are some of the most used capabilities of the better graphic manipulation programs. The list is by no means all inclusive. There are a myriad of choices associated with the application of most of these features.
Selection One of the prerequisites for many of the applications mentioned below is a method of selecting part(s) of an image, thus applying a change selectively without affecting the entire picture. Most graphics programs have several means of accomplishing this, such as a marquee tool, lasso, vector-based pen tools as well as more advanced facilities such as edge detection, masking, alpha compositing, and color and channel-based extraction.
Layers -
Another feature common to many graphics applications is that of Layers, which are analogous to sheets of transparent acetate (each containing separate elements that make up a combined picture), stacked on top of each other, each capable of being individually positioned, altered and blended with the layers below, without affecting any of the elements on the other layers. This is a fundamental workflow which has become the norm for the majority of programs on the market today, and enables maximum flexibility for the user whilst maintaining non-destructive editing principles and ease of use. Layers are used in digital image editing to separate different elements of an image. ...
Layers are used in digital image editing to separate different elements of an image. ...
Image size alteration Image editors can resize images in a process often called image scaling, making them larger, or smaller. High image resolution cameras can produce large images which are often reduced in size for Internet use. Image editor programs use a mathematical process called resampling to calculate new pixel values whose spacing is larger or smaller than the original pixel values. Images for Internet use are kept small, say 640 x 480 pixels which would equal 0.3 megapixels. Image scaling is the process of changing the size of a digital image. ...
Image resolution describes the detail an image holds. ...
This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as little squares and can easily be seen. ...
Cropping an image Digital editors are used to crop images. Cropping creates a new image by removing a desired rectangular portion from the image being cropped. The unwanted part of the image is discarded. Image cropping does not reduce the resolution of the area cropped. Best results are obtained when the original image has a high resolution. A primary reason for cropping is to improve the image composition in the new image. 2. ...
 Uncropped image from camera
 Lilly cropped from larger image
ImageMetadata File history File links Download high resolution version (2304x1728, 1533 KB) Summary Photo of Lilly taken by Alison Phillips in April of 2005 Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
ImageMetadata File history File links Download high resolution version (2304x1728, 1533 KB) Summary Photo of Lilly taken by Alison Phillips in April of 2005 Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Image File history File links LillyCroppedacp. ...
Image File history File links LillyCroppedacp. ...
Histogram Image editors have provisions to create an image histogram of the image being edited. The histogram plots the number of pixels in the image (vertical axis) with a particular brightness value (horizontal axis). Algorithms in the digital editor allow the user to visually adjust the brightness value of each pixel and to dynamically display the results as adjustments are made. Improvements in picture brightness and contrast can thus be obtained. In computer graphics, a color histogram is a representation of an image derived by counting the color of each pixel. ...
 Cropped image of sunflower
 Histogram of Sunflower image
ImageMetadata File history File links SunLou2. ...
ImageMetadata File history File links SunLou2. ...
Image File history File links SunHistacp. ...
Image File history File links SunHistacp. ...
Noise removal Image editors may feature a number of algorithms which can add or remove noise in an image. JPEG artifacts can be removed; dust & scratches can be removed and an image can be despeckled. Noise tends to invade images when pictures are taken in low light settings. A new picture can be given an 'antiquated' effect by adding uniform monochrome noise. A more thorough discussion of camera noise can be found at:Explanation of noise In computing, JPEG(pronounced JAY-peg; IPA: ) is a commonly used standard method of compression for photographic images and not for movie files for which MPEG compression is used. ...
Removal of Unwanted elements Most image editors can be used to remove unwanted branches, etc, using a "clone" tool. Removing these distracting elements draws focus to the subject, improving overall composition Composition is the plan, placement or arrangement of the elements of art in a work. ...
 Notice the branch in the original |
 The eye is drawn to the center of the globe |
Image File history File links Download high resolution version (1600x1200, 390 KB) Globe and High Court, Canberra File links The following pages link to this file: Digital image editing ...
Image File history File links Download high resolution version (1600x1200, 390 KB) Globe and High Court, Canberra File links The following pages link to this file: Digital image editing ...
Image File history File links Download high resolution version (1600x1200, 377 KB) Globe and High Court, Canberra File links The following pages link to this file: High Court of Australia Digital image editing ...
Image File history File links Download high resolution version (1600x1200, 377 KB) Globe and High Court, Canberra File links The following pages link to this file: High Court of Australia Digital image editing ...
Selective color change Image editors have the ability to selectively change the color of specific items in an image, given that the selected items are within a specific color range.
 An example of selective color change, the original is on the right.
Image File history File links Download high resolution version (4207x766, 686 KB) Summary This is a picture taken by me (the uploader) and edited in Photoshop CS2 to show the ability to selectively change the colors in a picture. ...
Image File history File links Download high resolution version (4207x766, 686 KB) Summary This is a picture taken by me (the uploader) and edited in Photoshop CS2 to show the ability to selectively change the colors in a picture. ...
Image gradient A gradient tool provides gradual blend of color which can be considered as an even gradation from low to high values, as shown in the illustration with arrows added showing the directions along which the image fades from white to black.
Image File history File links Gradient2. ...
Image File history File links Gradient2. ...
In graphics programs for digital image editing such as Photoshop (a bitmap graphics editor) and Adobe Illustrator (a vector graphics editor), the term gradient is used for a gradual blend of colour which can be considered as an even gradation from low to high values, as used from white to...
Image orientation Image editors are capable of altering an image to be rotated in any direction and to any degree. Mirror images can be created and images can be flipped (turned upside down). Images that are out of line can be straightened and perspective can be adjusted.
 An example of various kinds of image orientation.
Image File history File links Download high resolution version (1245x831, 593 KB) Summary This is an example of the types of image orientation that can be achieved in image editors. ...
Image File history File links Download high resolution version (1245x831, 593 KB) Summary This is an example of the types of image orientation that can be achieved in image editors. ...
Merging of images Many graphics applications are capable of merging one or more individual images into a single picture. The orientation and placement of each image can be controlled. The two images shown here were once individual studio portraits.
 John and Bertha Phillips — 1910
Image File history File links MomDadacp. ...
Image File history File links MomDadacp. ...
Special effects Image editors usually have a list of special effects that can create unusual results. Images may be skewed and distorted in various ways. Scores of special effects can be applied to an image which include various forms of distortion, artistic effects, geometric and texture effects, and combinations thereof.
 An example of some special effects that can be added to a picture.
Image File history File links Download high resolution version (1200x1600, 523 KB) Summary This is an example of the special kinds of effects that image editors can add to images. ...
Image File history File links Download high resolution version (1200x1600, 523 KB) Summary This is an example of the special kinds of effects that image editors can add to images. ...
Change color depth It is possible, using software, to change the color depth of images. Common color depths are 2, 4, 16, 256, 65.5 thousand and 16.7 million colors. The JPEG and PNG image formats are capable of storing 16.7 million colors (equal to 256 luminance values per color channel). In addition, grayscale images of 8 bits or less can be created, usually via conversion and downsampling from a full color image. Color depth is a computer graphics term describing the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. ...
In computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample. ...
A bit (binary digit) refers to a digit in the binary numeral system, which consists of base 2 digits (ie. ...
 An example of converting an image from color to grayscale.
Image File history File links Download high resolution version (1920x1280, 553 KB) Summary This is an example of converting an image from color to black and white. ...
Image File history File links Download high resolution version (1920x1280, 553 KB) Summary This is an example of converting an image from color to black and white. ...
Lens correction Photo manipulation packages have functions to correct images for various lens distortions including pincushion, fisheye and barrel distortions. The corrections are subtle, but can improve the appearance of some photographs.
Contrast change and brightening
 An example of contrast correction. Left side of the image is untouched. Image editors have provisions to change the contrast of images and brighten or darken the image. Many an underexposed image can be improved by using this feature. Recent advances have allowed more intelligent exposure correction whereby only pixels below a particular luminosity threshold are brightened, thereby brightening underexposed shadows without affecting the rest of the image. Image File history File links Download high resolution version (1024x768, 133 KB) Summary Example of photo editing: Contrast correction. ...
Image File history File links Download high resolution version (1024x768, 133 KB) Summary Example of photo editing: Contrast correction. ...
Sharpening and softening images Graphics programs can be used to both sharpen and blur images in a number of ways. Portraits often appear more pleasing when softened (particularly the background, to make the subject stand out more — this is an example of shallow depth of field which can be achieved with a camera by using a large aperture, or artificially within software, by selecting the background portion of an image, and then blurring it). The red-eye effect, which occurs when flash photos are taken when the pupil is too widely open (thus reflecting back the colour of the blood-rich retina), can also be eliminated. Edge enhancement is an extremely common technique used to make images appear sharper, although many purists frown on the end result as less natural-looking. An example of very shallow depth of field in a macro photograph. ...
a big (1) and a small (2) aperture For other uses, see Aperture (disambiguation). ...
The red-eye effect on a human. ...
Edge enhancement is a digital image processing filter that improves the apparent sharpness of an image or video. ...
Color adjustments The color of images can be altered in a variety of ways. Colors and be faded in and out, and tones can be changed, and the color balance can be improved, which is important if the picture was shot indoors with daylight film, or shot on a camera that with an incorrectly adjusted white balance. Special effects, like sepia and grayscale can be added to an image. In addition, more complicated procedures such as the mixing of color channels are possible using more advanced graphics editors. White light is commonly described by its color temperature. ...
Conclusion Image editors provide the means for altering and improving images in an almost endless number of ways. They accept images in a large variety of image formats, and after changes are made they allow the changed image to be saved in any number of image formats, at almost any size, and in varying degrees of compression. Most serious digital camera users will find the facilities of such a tool indispensable. In the hands of amateurs, they will obviously render amateurish results. However, for a beginner, the novelty of the power and features available to them, combined with their ease of use, image editing can be a lot of fun.
References - "Fantasy, fairy tale and myth collide in images: By digitally altering photos of landscapes, artist Anthony Goicolea creates an intriguing world," The Vancouver Sun (British Columbia); June 19, 2006.
- "It's hard to tell where pixels end and reality begins," The San Francisco Chronicle; September 26, 2006.
- "Virtual Art: From Illusion to Immersion," MIT Press 2002; Cambridge, Mass.
See also It has been suggested that this article or section be merged into Comparison of raster graphics editors. ...
Dynamic imaging is the amalgamation of digital imaging and workflow automation. ...
Digital painting Digital painting is an emerging artform in which traditional painting techniques such as watercolor, oils, impasto, etc. ...
Photo manipulation is the technique of modifying a photographic image by either analog or digital means. ...
Original painting Leif Eriksson Discovers America by Christian Krohg was subject for the Norwegian championship online manipulation contest 2006 won by R. Haraldsen. ...
Photoshopped early computing hoax by Lukket of Fark. ...
An image retrieval system is a computer system for browsing, searching and retrieving images from a large database of digital images. ...
Suppose the smiley face in the top left corner is an RGB bitmap image. ...
Digital image processing is the use of computer algorithms to perform image processing on digital images. ...
See also Category:Graphics file formats Here is a summary of the most common graphics file formats: Some file formats, e. ...
UPIICSA IPN - Binary image In the broadest sense, image processing is any form of information processing for which both the input and output are images, such as photographs or frames of video. ...
It has been suggested that CG artwork be merged into this article or section. ...
A Curve in Digital image editing is a way to emphasize colours or other elements in a picture. ...
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