Image editing encompasses the processes of altering images, whether they are digital photographs, traditional photo-chemical photographs, or illustrations. Traditional analog image editing is known as photo retouching, using tools such as an airbrush to modify photographs, or editing illustrations with any traditional art medium. Graphic software programs, which can be broadly grouped into vector graphics editors, raster graphics editors, 3D modelers, are the primary tools with which a user may manipulate and transform images. Many image editing programs are used to render or create computer art from scratch. Raster images 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. This article refers to bitmap graphics editors, which are used to alter photographs and other raster graphics. However, vector graphics software, such as Adobe Illustrator, CorelDRAW, Xara Designer Pro or Inkscape, are used to create and modify vector images, which are stored as descriptions of lines, Bézier curves, text instead of pixels.
It is easier to rasterize a vector image. Vector images can be modified more because they contain descriptions of the shapes for easy rearrangement, they are scalable, being rasterizable at any resolution. Camera or computer image editing programs offer basic automatic image enhancement features that correct color hue and brightness imbalances as well as other image editing features, such as red eye removal, sharpness adjustments, zoom features and automatic cropping; these are called automatic because they happen without user interaction or are offered with one click of a button or mouse button or by selecting an option from a menu. Additionally, some automatic editing features offer a combination of editing actions with little or no user interaction. Many image file formats use data compression to 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 taken place.
Both cameras and computer programs allow the user to set the level of compression. Some compression algorithms, such as those used in PNG file format, are lossless, which means no information is lost when the file is saved. By contrast, the JPEG file format uses a lossy compression algorithm by which the greater the compression, the more information is lost reducing image quality or detail that can not be restored. JPEG uses knowledge of the way the human brain and eyes perceive color to make this loss of detail less noticeable. 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. One of the prerequisites for many of the applications mentioned below is a method of selecting part 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 for selecting rectangular or other regular polygon-shaped regions, a lasso tool for freehand selection of a region, a magic wand tool that selects objects or regions in the image defined by proximity of color or luminance, vector-based pen tools,as well as more advanced facilities such as edge detection, alpha compositing, color and channel-based extraction.
The border of a selected area in an image is animated with the marching ants effect to help the user to distinguish the selection border from the image background. Another feature common to many graphics applications is that of Layers, which are analogous to sheets of transparent acetate, stacked on top of each other, each capable of being individually positioned 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, enables maximum flexibility for the user while maintaining non-destructive editing principles and ease of use. Image editors can resize images in a process called image scaling, making them larger, or smaller. High image resolution cameras can produce large images which are 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. Digital editors are used to crop images. Cropping creates a new image by selecting 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. A primary reason for cropping is to improve the image composition in the new image. Using a selection tool, the outline of the figure or element in the picture is traced/selected, the background is removed. Depending on how intricate the "edge" is this may be less difficult to do cleanly. For example, individual hairs can require a lot of work. Hence the use of the "green screen" technique which allows one to remove the bac
Graphic design is the process of visual communication and problem-solving through the use of typography and illustration. The field is considered a subset of visual communication and communication design, but sometimes the term "graphic design" is used synonymously. Graphic designers create and combine symbols and text to form visual representations of ideas and messages, they use typography. Common uses of graphic design include corporate design, editorial design, wayfinding or environmental design, web design, communication design, product packaging and signage; the term graphic design was coined by William Addison Dwiggins in 1922. However, the origins of graphic design can be traced from the origins of human existence, from the caves of Lascaux, to Rome's Trajan's Column to the illuminated manuscripts of the Middle Ages, to the neon lights of Ginza, Tokyo. In "Babylon, artisans pressed cuneiform inscriptions into clay bricks or tablets which were used for construction; the bricks gave information such as the name of the reigning monarch, the builder, or some other dignitary".
This was the first known road sign announcing the name of the governor of a state or mayor of the city. The Egyptians developed communication by hieroglyphics that used picture symbols dating as far back as 136 B. C. found on the Rosetta Stone. "The Rosetta stone, found by one of Napoleon's engineers was an advertisement for the Egyptian ruler, Ptolemy as the "true Son of the Sun, the Father of the Moon, the Keeper of the Happiness of Men"" The Egyptians invented papyrus, paper made from reeds found along the Nile, on which they transcribed advertisements more common among their people at the time. During the "Dark Ages", from 500 AD to 1450 AD, monks created illustrated manuscripts. In both its lengthy history and in the recent explosion of visual communication in the 20th and 21st centuries, the distinction between advertising, graphic design and fine art has disappeared, they share many elements, principles, practices and sometimes the same benefactor or client. In advertising, the ultimate objective is the sale of services.
In graphic design, "the essence is to give order to information, form to ideas and feeling to artifacts that document human experience."Graphic design in the United States began with Benjamin Franklin who used his newspaper The Pennsylvania Gazette, to master the art of publicity to promote his own books and to influence the masses. "Benjamin Franklin's ingenuity gained in strength as did his cunning and in 1737 he had replaced his counterpart in Pennsylvania, Andrew Bradford as postmaster and printer after a competition he instituted and won. He showed his prowess by running an ad in his General Magazine and the Historical Chronicle of British Plantations in America that stressed the benefits offered by a stove he invented, named the Pennsylvania Fireplace, his invention is known as the Franklin stove. "American advertising imitated British newspapers and magazines. Advertisements were printed in scrambled type and uneven lines. Franklin better organized this by adding 14-point type for the first line of the advertisement.
Franklin added something that London printers had not attempted. Franklin was the first to utilize logos, which were early symbols that announced such services as opticians by displaying golden spectacles. Franklin taught advertisers; some advertisements ran for 10-20 lines, including color, names and sizes of the goods that were offered. During the Tang Dynasty wood blocks were cut to print on textiles and to reproduce Buddhist texts. A Buddhist scripture printed in 868 is the earliest known printed book. Beginning in the 11th century, longer scrolls and books were produced using movable type printing, making books available during the Song dynasty. During the 17th-18th century movable type was used for handbills or trade cards which were printed from wood or copper engravings; these documents announced its location. English painter William Hogarth used his skill in engraving was one of the first to design for business trade. In Mainz Germany, in 1448, Johann Gutenberg introduced movable type using a new metal alloy for use in a printing press and opened a new era of commerce.
This made graphics more available since mass printing dropped the price of printing material significantly. Most advertising was word of mouth. In France and England, for example, criers announced products for sale just as ancient Romans had done; the printing press made books more available. Aldus Manutius developed the book structure that became the foundation of western publication design; this era of graphic design is called Old Style. Additionally, William Caxton, England's first printer produced religious books, but had trouble selling them, he discovered the use of leftover pages and used them to announce the books and post them on church doors. This practice was termed "squis" or "pin up" posters, in 1612, becoming the first form of print advertising in Europe; the term Siquis came from the Roman era when public notices were posted stating "if anybody...", which in Latin is "si quis". These printed announcements were followed by public registers of wants called want ads and in some areas such as the first periodical in Paris advertising was termed "advices".
The "Advices" were what we know
RGB color model
The RGB color model is an additive color model in which red and blue light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additive primary colors, red and blue; the main purpose of the RGB color model is for the sensing and display of images in electronic systems, such as televisions and computers, though it has been used in conventional photography. Before the electronic age, the RGB color model had a solid theory behind it, based in human perception of colors. RGB is a device-dependent color model: different devices detect or reproduce a given RGB value differently, since the color elements and their response to the individual R, G, B levels vary from manufacturer to manufacturer, or in the same device over time, thus an RGB value does not define the same color across devices without some kind of color management. Typical RGB input devices are color TV and video cameras, image scanners, digital cameras. Typical RGB output devices are TV sets of various technologies and mobile phone displays, video projectors, multicolor LED displays and large screens such as JumboTron.
Color printers, on the other hand subtractive color devices. This article discusses concepts common to all the different color spaces that use the RGB color model, which are used in one implementation or another in color image-producing technology. To form a color with RGB, three light beams must be superimposed; each of the three beams is called a component of that color, each of them can have an arbitrary intensity, from off to on, in the mixture. The RGB color model is additive in the sense that the three light beams are added together, their light spectra add, wavelength for wavelength, to make the final color's spectrum; this is opposite to the subtractive color model that applies to paints, inks and other substances whose color depends on reflecting the light under which we see them. Because of properties, these three colours create white, this is in stark contrast to physical colours, such as dyes which create black when mixed. Zero intensity for each component gives the darkest color, full intensity of each gives a white.
When the intensities for all the components are the same, the result is a shade of gray, darker or lighter depending on the intensity. When the intensities are different, the result is a colorized hue, more or less saturated depending on the difference of the strongest and weakest of the intensities of the primary colors employed; when one of the components has the strongest intensity, the color is a hue near this primary color, when two components have the same strongest intensity the color is a hue of a secondary color. A secondary color is formed by the sum of two primary colors of equal intensity: cyan is green+blue, magenta is red+blue, yellow is red+green; every secondary color is the complement of one primary color. The RGB color model itself does not define what is meant by red and blue colorimetrically, so the results of mixing them are not specified as absolute, but relative to the primary colors; when the exact chromaticities of the red and blue primaries are defined, the color model becomes an absolute color space, such as sRGB or Adobe RGB.
The choice of primary colors is related to the physiology of the human eye. The normal three kinds of light-sensitive photoreceptor cells in the human eye respond most to yellow and violet light; the difference in the signals received from the three kinds allows the brain to differentiate a wide gamut of different colors, while being most sensitive to yellowish-green light and to differences between hues in the green-to-orange region. As an example, suppose that light in the orange range of wavelengths enters the eye and strikes the retina. Light of these wavelengths would activate both the medium and long wavelength cones of the retina, but not equally—the long-wavelength cells will respond more; the difference in the response can be detected by the brain, this difference is the basis of our perception of orange. Thus, the orange appearance of an object results from light from the object entering our eye and stimulating the different cones but to different degrees. Use of the three primary colors is not sufficient to reproduce all colors.
The RGB color model is based on the Young–Helmholtz theory of trichromatic color vision, developed by Thomas Young and Hermann Helmholtz in the early to mid nineteenth century, on James Clerk Maxwell's c
HSL and HSV
HSL and HSV are alternative representations of the RGB color model, designed in the 1970s by computer graphics researchers to more align with the way human vision perceives color-making attributes. In these models, colors of each hue are arranged in a radial slice, around a central axis of neutral colors which ranges from black at the bottom to white at the top; the HSV representation models the way paints of different colors mix together, with the saturation dimension resembling various shades of brightly colored paint, the value dimension resembling the mixture of those paints with varying amounts of black or white paint. The HSL model attempts to resemble more perceptual color models such as the Natural Color System or Munsell color system, placing saturated colors around a circle at a lightness value of 1⁄2, where a lightness value of 0 or 1 is black or white, respectively. HSL and HSV are both cylindrical geometries, with hue, their angular dimension, starting at the red primary at 0°, passing through the green primary at 120° and the blue primary at 240°, wrapping back to red at 360°.
In each geometry, the central vertical axis comprises the neutral, achromatic, or gray colors, ranging from black at lightness 0 or value 0, the bottom, to white at lightness 1 or value 1, the top. In both geometries, the additive primary and secondary colors—red, green, cyan and magenta—and linear mixtures between adjacent pairs of them, sometimes called pure colors, are arranged around the outside edge of the cylinder with saturation 1; these saturated colors have lightness 0.5 in HSL, while in HSV they have value 1. Mixing these pure colors with black—producing so-called shades—leaves saturation unchanged. In HSL, saturation is unchanged by tinting with white, only mixtures with both black and white—called tones—have saturation less than 1. In HSV, tinting alone reduces saturation; because these definitions of saturation—in which dark or light near-neutral colors are considered saturated —conflict with the intuitive notion of color purity a conic or biconic solid is drawn instead, with what this article calls chroma as its radial dimension, instead of saturation.
Confusingly, such diagrams label this radial dimension "saturation", blurring or erasing the distinction between saturation and chroma. As described below, computing chroma is a helpful step in the derivation of each model; because such an intermediate model—with dimensions hue, HSV value or HSL lightness—takes the shape of a cone or bicone, HSV is called the "hexcone model" while HSL is called the "bi-hexcone model". The HSL color space was invented in 1938 by Georges Valensi as a method to add color encoding to existing monochrome broadcasts, allowing existing receivers to receive new color broadcasts without modification as the luminance signal is broadcast unmodified, it has been used in all major analog broadcast television encoding including NTSC, PAL and SECAM and all major digital broadcast systems and is the basis for composite video. Most televisions, computer displays, projectors produce colors by combining red and blue light in varying intensities—the so-called RGB additive primary colors.
The resulting mixtures in RGB color space can reproduce a wide variety of colors. Furthermore, neither additive nor subtractive color models define color relationships the same way the human eye does. For example, imagine we have an RGB display whose color is controlled by three sliders ranging from 0–255, one controlling the intensity of each of the red and blue primaries. If we begin with a colorful orange , with sRGB values R = 217, G = 118, B = 33, want to reduce its colorfulness by half to a less saturated orange , we would need to drag the sliders to decrease R by 31, increase G by 24, increase B by 59, as pictured below. In an attempt to accommodate more traditional and intuitive color mixing models, computer graphics pioneers at PARC and NYIT developed the HSV model in the mid-1970s, formally described by Alvy Ray Smith in the August 1978 issue of Computer Graphics. In the same issue and Greenberg described the HSL model—whose dimensions they labeled hue, relative chroma, intensity—and compared it to HSV.
Their model was based more upon how colors are organized and conceptualized in human vision in terms of other color-making attributes, such as hue and chroma. The following year, 1979, at SIGGRAPH, Tektronix introduced graphics terminals using HSL for color designation, the Computer Graphics Standards Committee recommended it in their annual status report; these models were useful not only because they were more intuitive than raw RGB values, but because the conversions to and from RGB were fast to compute: they could run in real time on the hardware of the 1970s. These models and similar ones have become ubiquito
In typography, a typeface is a set of one or more fonts each composed of glyphs that share common design features. Each font of a typeface has a specific weight, condensation, slant, italicization and designer or foundry. For example, "ITC Garamond Bold Condensed Italic" means the bold, condensed-width, italic version of ITC Garamond, it is a different font from "ITC Garamond Condensed Italic" and "ITC Garamond Bold Condensed", but all are fonts within the same typeface, "ITC Garamond". ITC Garamond is a different typeface from "Adobe Garamond" or "Monotype Garamond". There are thousands of different typefaces with new ones being developed constantly; the art and craft of designing typefaces is called type design. Designers of typefaces are called type designers and are employed by type foundries. In digital typography, type designers are sometimes called font developers or font designers; every typeface is a collection of glyphs, each of which represents an individual letter, punctuation mark, or other symbol.
The same glyph may be used for characters from different scripts, e.g. Roman uppercase A looks the same as Cyrillic uppercase А and Greek uppercase alpha. There are typefaces tailored for special applications, such as map-making or astrology and mathematics; the term typeface is confused with the term font. Before the advent of digital typography and desktop publishing, the two terms had more understood meanings. In professional typography, the term typeface is not interchangeable with the word font, because the term font has been defined as a given alphabet and its associated characters in a single size. For example, 8-point Caslon Italic was one font, 10-point Caslon Italic was another. Fonts came in specific sizes determining the size of characters, in quantities of sorts or number of each letter provided; the design of characters in a font took into account all these factors. As the range of typeface designs increased and requirements of publishers broadened over the centuries, fonts of specific weight and stylistic variants have led to font families, collections of related typeface designs that can include hundreds of styles.
A font family is a group of related fonts which vary only in weight, width, etc. but not design. For example, Times is a font family, whereas Times Roman, Times Italic and Times Bold are individual fonts making up the Times family. Font families include several fonts, though some, such as Helvetica, may consist of dozens of fonts; the distinction between font and typeface is that a font designates a specific member of a type family such as roman, boldface, or italic type, while typeface designates a consistent visual appearance or style which can be a "family" or related set of fonts. For example, a given typeface such as Arial may include roman and italic fonts. In the metal type era, a font meant a specific point size, but with digital scalable outline fonts this distinction is no longer valid, as a single font may be scaled to any size; the first "extended" font families, which included a wide range of widths and weights in the same general style emerged in the early 1900s, starting with ATF's Cheltenham, with an initial design by Bertram Grosvenor Goodhue, many additional faces designed by Morris Fuller Benton.
Examples include Futura, Lucida, ITC Officina. Some became superfamilies as a result such as Linotype Syntax, Linotype Univers. Typeface superfamilies began to emerge when foundries began to include typefaces with significant structural differences, but some design relationship, under the same general family name. Arguably the first superfamily was created when Morris Fuller Benton created Clearface Gothic for ATF in 1910, a sans serif companion to the existing Clearface; the superfamily label does not include quite different designs given the same family name for what would seem to be purely marketing, rather than design, considerations: Caslon Antique, Futura Black and Futura Display are structurally unrelated to the Caslon and Futura families and are not considered part of those families by typographers, despite their names. Additional or supplemental glyphs intended to match a main typeface have been in use for centuries. In some formats they have been marketed as separate fonts. In the early 1990s, the Adobe Systems type group introduced the idea of expert set fonts, which had a standardized set of additional glyphs, including small caps, old style figures, additional superior letters and ligatures not found in the main fonts for the typeface.
Supplemental fonts have included alternate letters such as swashes and alternate character sets, complementing the regular fonts under the same family. However, with introduction of font formats such as OpenType, those supplemental glyphs were merged into the main fonts, relying on specific software capabilities to access the alternate glyphs. Since Apple's and Microsoft's operating systems supported different character sets in the platform related fonts, some foundries used expert fonts in a different way; these fonts included the characters which were missing on either Macintosh or Windows computers, e.g. fractions, ligatures or some accented glyphs. The goal was to deliver t
Open-source software is a type of computer software in which source code is released under a license in which the copyright holder grants users the rights to study and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration. Open-source software development generates an more diverse scope of design perspective than any company is capable of developing and sustaining long term. A 2008 report by the Standish Group stated that adoption of open-source software models have resulted in savings of about $60 billion per year for consumers. In the early days of computing and developers shared software in order to learn from each other and evolve the field of computing; the open-source notion moved to the way side of commercialization of software in the years 1970-1980. However, academics still developed software collaboratively. For example Donald Knuth in 1979 with the TeX typesetting system or Richard Stallman in 1983 with the GNU operating system.
In 1997, Eric Raymond published The Cathedral and the Bazaar, a reflective analysis of the hacker community and free-software principles. The paper received significant attention in early 1998, was one factor in motivating Netscape Communications Corporation to release their popular Netscape Communicator Internet suite as free software; this source code subsequently became the basis behind SeaMonkey, Mozilla Firefox and KompoZer. Netscape's act prompted Raymond and others to look into how to bring the Free Software Foundation's free software ideas and perceived benefits to the commercial software industry, they concluded that FSF's social activism was not appealing to companies like Netscape, looked for a way to rebrand the free software movement to emphasize the business potential of sharing and collaborating on software source code. The new term they chose was "open source", soon adopted by Bruce Perens, publisher Tim O'Reilly, Linus Torvalds, others; the Open Source Initiative was founded in February 1998 to encourage use of the new term and evangelize open-source principles.
While the Open Source Initiative sought to encourage the use of the new term and evangelize the principles it adhered to, commercial software vendors found themselves threatened by the concept of distributed software and universal access to an application's source code. A Microsoft executive publicly stated in 2001 that "open source is an intellectual property destroyer. I can't imagine something that could be worse than this for the software business and the intellectual-property business." However, while Free and open-source software has played a role outside of the mainstream of private software development, companies as large as Microsoft have begun to develop official open-source presences on the Internet. IBM, Oracle and State Farm are just a few of the companies with a serious public stake in today's competitive open-source market. There has been a significant shift in the corporate philosophy concerning the development of FOSS; the free-software movement was launched in 1983. In 1998, a group of individuals advocated that the term free software should be replaced by open-source software as an expression, less ambiguous and more comfortable for the corporate world.
Software licenses grant rights to users which would otherwise be reserved by copyright law to the copyright holder. Several open-source software licenses have qualified within the boundaries of the Open Source Definition; the most prominent and popular example is the GNU General Public License, which "allows free distribution under the condition that further developments and applications are put under the same licence", thus free. The open source label came out of a strategy session held on April 7, 1998 in Palo Alto in reaction to Netscape's January 1998 announcement of a source code release for Navigator. A group of individuals at the session included Tim O'Reilly, Linus Torvalds, Tom Paquin, Jamie Zawinski, Larry Wall, Brian Behlendorf, Sameer Parekh, Eric Allman, Greg Olson, Paul Vixie, John Ousterhout, Guido van Rossum, Philip Zimmermann, John Gilmore and Eric S. Raymond, they used the opportunity before the release of Navigator's source code to clarify a potential confusion caused by the ambiguity of the word "free" in English.
Many people claimed that the birth of the Internet, since 1969, started the open-source movement, while others do not distinguish between open-source and free software movements. The Free Software Foun
A color picker is a graphical user interface widget found within graphics software or online, used to select colors and sometimes to create color schemes. A color picker is used to adjust color values. In graphic design and image editing, users choose colors via an interface with a visual representation of a color—organized with quasi-perceptually-relevant hue and saturation dimensions – instead of keying in alphanumeric text values; because color appearance depends on comparison of neighboring colors, many interfaces attempt to clarify the relationships between colors. Color tools can vary in their interface; some may use sliders, text boxes for color values, or direct manipulation. A two dimensional square is used to create a range of color values that can be clicked on or selected in some other manner. Drag and drop, color droppers, various other forms of interfaces are used as well. Color values are displayed numerically, so they can be remembered and keyed-in such three values of 0-255 representing red and blue, respectively.
Alexis Spectral Data Color balance Color space RGB color space Feisner, Edith Anderson.