Image

Images may be two-dimensional, such as a photograph, screen display, and as well as a three-dimensional, such as a statue. They may be captured by optical devices—such as cameras, mirrors,lenses, telescopes, microscopes, etc. and natural objects and phenomena, such as the human eye or water surfaces.

The word image is also used in the broader sense of any two-dimensional figure such as a map, a graph, a pie chart, or an abstract painting. In this wider sense, images can also be rendered manually, such as by drawing, painting, carving, rendered automatically by printing or computer graphics technology, ordeveloped by a combination of methods, especially in a pseudo-photograph.

A volatile image is one that exists only for a short period of time. This may be a reflection of an object by a mirror, a projection of a camera obscura, or a scene displayed on a cathode ray tube. A fixed image, also called a hard copy, is one that has been recorded on a material object, such as paper or textile byphotography or digital processes.

A mental image exists in an individual's mind: something one remembers or imagines. The subject of an image need not be real; it may be an abstract concept, such as a graph, function, or "imaginary" entity. For example, Sigmund Freud claimed to have dreamed purely in aural-images of dialogs. The development of synthetic acoustic technologies and the creation of sound art have led to a consideration of the possibilities of a sound-image made up of irreducible phonic substance beyond linguistic or musicological analysis.

A still image is a single static image, as distinguished from a moving image (see below). This phrase is used in photography, visual media and the computer industry to emphasize that one is not talking about movies, or in very precise or pedantic technical writing such as a standard.

A film still is a photograph taken on the set of a movie or television program during production, used for promotional purposes.

Video compositing

2D Graphics

Displayed representation of a scene or an object along two axes of reference: height and width (x and y).

3D Graphics

Displayed representation of a scene or an object that appears to have three axes of reference: height, width, and depth (x, y, and z).

3D Pipeline

The process of 3D graphics can be divided into three-stages: tessellation, geometry, and rendering. In the tessellation stage, a described model of an object is created, and the object is then converted to a set of polygons. The geometry stage includes transformation, lighting, and setup. The rendering stage, which is critical for 3D image quality, creates a two dimensional display from the polygons created in the geometry stage.

Alpha Blending

The real world is composed of transparent, translucent, and opaque objects. Alpha blending is a technique for adding transparency information for translucent objects. It is implemented by rendering polygons through a stipple mask whose on-off density is proportional to the transparency of the object. The resultant color of a pixel is a combination of the foreground and background color.

Typically, alpha has a normalized value of 0 to 1 for each color pixel.

new pixel = (alpha)(pixel A color) + (1 - alpha)(pixel B color)

Alpha Buffer

An extra Color channel to hold transparency information; pixels become quad values (RGBA). In a 32-bit frame buffer there are 24 bits of color, 8 each for red, green, and blue, along with an 8-bit alpha channel.

Anti-aliasing

Anti-aliasing is sub pixel interpolation, a technique that makes edges appear to have better resolution.

Atmospheric Effect

Effects, such as fog and depth cueing, that improve the rendering of real-world environments.

Bitmap

A Bitmap is a pixel by pixel image.

Bilinear Filtering

Bilinear filtering is a method of anti-aliasing texture maps. A texture-aliening artifact occurs due to sampling on a finite pixel grid. Point-sampled telexes jump from one pixel to another at random times. This aliening is very noticeable on slowly rotating or moving polygons. The texture image jumps and shears along pixel boundaries. To eliminate this problem, bilinear filtering takes a weighted average of four adjacent texture pixels to create a single telex.

BitBLTs

The BitBLT is the single most important acceleration function for windowed GUI environments. A BitBLT is simply the movement of a block of data from one place to another, taking into account the special requirements and arrangements of the graphics memory. For example, this function is utilized every time a window is moved; in which case, the BitBLT is a simple Pixel Block Transfer. More complicated cases may occur where some transformation of the source data is to occur, such as in a Color Expanded Block Transfer, where each monochromatic bit in the source is expanded to the color in the foreground or background register before being written to the display.

Sound recording and reproduction

Sound recording and reproduction is an electrical or mechanical inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording. Acoustic analog recording is achieved by a small microphone diaphragm that can detect changes in atmospheric pressure (acoustic sound waves) and record them as a graphic representation of the sound waves on a medium such as a phonograph (in which a stylus senses grooves on a record). In magnetic tape recording, the sound waves vibrate the microphone diaphragm and are converted into a varying electric current, which is then converted to a varying magnetic field by an electromagnet, which makes a representation of the sound as magnetized areas on a plastic tape with a magnetic coating on it. Analog sound reproduction is the reverse process, with a bigger loudspeaker diaphragm causing changes to atmospheric pressure to form acoustic sound waves. Electronically generated sound waves may also be recorded directly from devices such as an electric guitar pickup or a synthesizer, without the use of acoustics in the recording process other than the need for musicians to hear how well they are playing during recording sessions.

Digital recording and reproduction converts the analog sound signal picked up by the microphone to a digital form by a process of digitization, allowing it to be stored and transmitted by a wider variety of media. Digital recording stores audio as a series of binary numbers representing samples of the amplitude of the audio signal at equal time intervals, at a sample rate so fast that the human ear perceives the result as continuous sound. Digital recordings are considered higher quality than analog recordings not necessarily because they have higher fidelity(wider frequency response or dynamic range), but because the digital format can prevent much loss of quality found in analog recording due to noise and electromagnetic interference in playback, and mechanical deterioration or damage to the storage medium. A digital audio signal must be reconverted to analog form during playback before it is applied to a loudspeaker or earphones.

Text

"Write" redirects here. For other uses, see Write (disambiguation).

Writing is the representation of language in a textual medium through the use of a set of signs or symbols (known as a writing system).^[1] It is distinguished from illustration, such ascave drawing and painting, and non-symbolic preservation of language via non-textual media, such as magnetic tape audio.

Writing is an extension of human language across time and space. Writing most likely began as a consequence of political expansion in ancient cultures, which needed reliable means for transmitting information, maintaining financial accounts, keeping historical records, and similar activities. Around the 4th millennium BC, the complexity of trade and administration outgrew the power of memory, and writing became a more dependable method of recording and presenting transactions in a permanent form^[2]. In both Mesoamerica and Ancient Egyptwriting may have evolved through calendrics and a political necessity for recording historical and environmental events.

Animation

Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. It is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in a number of ways. The most common method of presenting animation is as a motion picture or video program, although several other forms of presenting animation also exist.

In film and video, footage is the raw, unedited material as it had been originally filmed by movie camera or recorded by a video camera which usually must be edited to create a motion picture, video clip, television show or similar completed work. More loosely, footage can also refer to all sequences used in film and video editing, such as special effects and archive material (for special cases of this, see stock footage andB roll). Since the term originates in film, footage is only used for recorded images, such as film stock, videotapes or digitized clips – on live television, the signals from the cameras are called sources instead.

The origin of the term "footage" is that early 35 mm Silent film has traditionally been measured in feet and frames; the fact that film was measured by length in cutting rooms, and that there are 16 frames (4-perf film format) in a foot of 35 mm film which roughly represented 1 second of silent film, made footage a natural unit of measure for film. The term then became used figuratively to describe moving image material of any kind.

Television footage, especially news footage, is often traded between broadcasting organizations, but good footage usually commands a high price. The actual sum depends on duration, age, size of intended audience, duration of licensing and other factors. Amateur video footage of current events can also often fetch a high price on the market – scenes shot inside the World Trade Center during the September 11, 2001 attacks were reportedly sold for US$45,000.^[1] Sometimes film projects will also sell or trade footage, usually second unit material not used in the final cut. For example, the end of the non-director's cut version of Blade Runner used landscape views that were originally shot for The Shining before the script was modified after shooting had finished.