A raster graphics editor is a
computer program
A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. Computer programs are one component of software, which also includes software documentation, documentation and oth ...
that allows users to
create and
edit images interactively on the computer screen and save them in one of many
raster graphics
upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for ...
file formats
A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free.
Some file formats ...
(also known as
bitmap images) such as
JPEG
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
,
PNG, and
GIF.
Comparison to vector graphic editors
Vector graphics editors are often contrasted with raster graphics editors, yet their capabilities complement each other. The technical difference between vector and raster editors stem from the difference between vector and raster images.
Vector graphics
Vector graphics is a form of computer graphics in which visual images are created directly from geometric shapes defined on a Cartesian plane, such as points, lines, curves and polygons. The associated mechanisms may include vector display ...
are created mathematically, using
geometric formula
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...
s. Each element is created and manipulated numerically; essentially using
Cartesian coordinates
A Cartesian coordinate system (, ) in a plane is a coordinate system that specifies each point uniquely by a pair of numerical coordinates, which are the signed distances to the point from two fixed perpendicular oriented lines, measured in ...
for the placement of key points, and then a mathematical algorithm to connect the dots and define the colors.
Raster images include
digital photos. A raster image is made up of rows and columns of dots, called
pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device.
In most digital display devices, pixels are the ...
s, and is generally more
photo-realistic. This is the standard form for
digital cameras; whether it be a
.raw file or
.jpg
JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and im ...
file, the concept is the same. The image is represented pixel by pixel, like a microscopic jigsaw puzzle.
Vector editors tend to be better suited for
graphic design
Graphic design is a profession, academic discipline and applied art whose activity consists in projecting visual communications intended to transmit specific messages to social groups, with specific objectives. Graphic design is an interdiscip ...
,
page layout,
typography
Typography is the art and technique of arranging type to make written language legible, readable and appealing when displayed. The arrangement of type involves selecting typefaces, point sizes, line lengths, line-spacing ( leading), an ...
,
logo
A logo (abbreviation of logotype; ) is a graphic mark, emblem, or symbol used to aid and promote public identification and recognition. It may be of an abstract or figurative design or include the text of the name it represents as in a wo ...
s, sharp-edged artistic
illustrations, ''e.g.'',
cartoons, clip art, complex geometric patterns,
technical illustrations,
diagram
A diagram is a symbolic representation of information using visualization techniques. Diagrams have been used since prehistoric times on walls of caves, but became more prevalent during the Enlightenment. Sometimes, the technique uses a three ...
ming and
flowcharting.
Advanced raster editors, like
GIMP and
Adobe Photoshop
Adobe Photoshop is a raster graphics editor developed and published by Adobe Inc. for Windows and macOS. It was originally created in 1988 by Thomas and John Knoll. Since then, the software has become the industry standard not only in rast ...
, use vector methods (mathematics) for general layout and elements such as text, but are equipped to deal with raster images down to the pixel and often have special capabilities in doing so, such as brightness/contrast, and even adding "lighting" to a raster image or photograph.
Common features
*
Select a region for editing
* Draw lines with simulated brushes of different color, size, shape and pressure
* Fill a region with a single color,
gradient of colors, or a texture
* Select a color using different color models, ''e.g.'',
RGB,
HSV, or by using a
color dropper
* Edit and convert between various
color models.
* Add typed letters in various
font styles
* Remove imperfections from photo images
* Composite editing using
layers
Layer or layered may refer to:
Arts, entertainment, and media
* ''Layers'' (Kungs album)
* ''Layers'' (Les McCann album)
* ''Layers'' (Royce da 5'9" album)
*"Layers", the title track of Royce da 5'9"'s sixth studio album
* Layer, a female Maveri ...
* Apply filters for effects including sharpening and blurring
* Convert between various
image file formats
See also
*
Comparison of raster graphics editors
*
Vector graphics editor
*
Texture map
Texture mapping is a method for mapping a texture on a computer-generated graphic. Texture here can be high frequency detail, surface texture, or color.
History
The original technique was pioneered by Edwin Catmull in 1974.
Texture mapping ...
*
Text editor
*
3D modelling software
References
External links
*
{{Raster graphics editors