Ensuring the long term accessibility and usability of records stored as digital images is largely dependent on how digital imaging systems are designed, implemented, managed, and migrated.
Digital Image Processing
To be effective in management decisions, a geographic information system requires timely, accurate update of many of its spatial data elements.
digital image -- a two-dimensional array of regularly spaced picture elements (pixels) constituting a picture.
digital volume -- a three-dimensional array of regularly spaced volume elements (voxels) constituting a volume.
Digital images include both digital photographs, and images that have been created or modified on a computer.
Digital image processing techniques play an important role in the analysis of complex problems. These techniques combine the present intensive computer technology with the unique human ability to visualise complexity and to interpret these images.
Digital Image Analytical Plotter (ISM)
DID
Data information delivery; Data information description; Digital Image Data ...
[digital image processing] In digital image processing, a measure of the theoretical distance between two normal distributions of spectral classes, ...
The digital images for the library are gathered using Facet Mobile360® mapping vans, which are equipped with either four or seven high-resolution digital cameras, GPS and inertial navigation hardware and computers.
Remote Sensing Digital Image Analysis, by John A. Richards, Springer-Verlag, 1986.
Personal communication, between progam author and Ali R. Vali, Space Research Center, University of Texas, Austin, 1990.
Not to be confused with satellite remote sensing which produces digital images, aerial photography provides black and white, color and infrared photographs on film.
Aerial Photography and Remote Sensing (Crum/Geographer's Craft) -- Electromagnetic waves and spectrum; infrared radiation; applications of aerial photography; digital image processing; satellite imaging; radar scanning; remote sensing and GIS; etc.
digital image-An image where the property being measured has been converted from a continuous range of analogue values to a range expressed by a finite number of integers, usually recorded as binary codes from 0 to 255, or as one byte.
A digital orthophoto is a digital image of an aerial photograph in which displacements caused by the camera and the terrain have been removed. It combines the image characteristics of a photograph with the geometric qualities of a map.
A raster data type is, in essence, any type of digital image. Anyone who is familiar with digital photography will recognize the pixel as the smallest individual unit of an image.
Image editors are specialized for the manipulation of digital images, mainly by means of free-hand drawing/painting and signal processing operations.
Colour management is a major concern in the distribution of digital imagery, on the Internet and in the graphic arts industry, right up to and including the printing stage.
The view on his computer screen w as constructed from a series of aerial photographs that had been scanned and converted to form a digital image.
There are several image-browsing programs on the market, which serve to organize and provide access to digital images. If you buy a digital camera today, you'll probably receive some sort of image browser as part of the package.
Document scanning involves using scanners to capture a digital image of a map, manuscript, or other document. Once the image is stored, a variety of processes can be applied, depending on the image's intended use.
Remote-sensing images Remote sensing images are normally in the form of digital images (figure 5.4).
ikeGPS produces a geotagged digital image of each target. In February, Science Applications International Corporation and Surveylab signed a six-year agreement giving SAIC exclusive rights to incorporate the Selective Availability and Anti-Spoofing ...
Orthophotographs are digital images that are produced by making geometric corrections to scanned aerial photographs.
Digital Orthophotography - A photo-quality digital image of surface features in their geometrically corrected, true map projection. The orthorectification process ties each pixel in a digital image to its true earth location.
The multi spectral scanner (MSS) provided digital images that could be used for computer analysis. It had four bands (4, 5, 6, and 7) in the visible and near infrared part of the spectrum.
1. Heads-Up digitizing is a technique that is useful for capturing or updating data from digital imagery on screen. High-resolution digital imagery now allows GIS users to edit and delineate features directly on the screen using desktop GIS software.
Both can record handwritten notes, sketches, digital images, and voice recordings to enhance the field book.
To obtain a more precise reading, the reading is either estimated (single or three-wire method) or read with an optical micrometer or a digital image. Precision leveling requires one-piece rods that are calibrated for accuracy and thermal expansion.
GeoTIFF - A binary digital image format commonly used by GIS software that is characterized by reference information embedded in the file header as opposed to an external file.
At times it is desirable to overlay a digital image, whether a map or a drawing, onto your ArcGIS project.
ArcMap supports a range of image files, but TIFFs and JPEGs are preferable.
Modern maps are usually based on overlapping photographs taken from an aircraft (aerial photography) or digital images from a satellite (satellite imagery).
This data, when merged with GPS precision navigation will create the type of digital images needed to provide clear out-the-window vision needed to greatly reduce flight into terrain type accidents -- the number one cause of aircraft fatalities ...
JPEG is designed for compressing either full colour or grey-scale digital images of 'natural', real-world scenes. It does not work so well on non-realistic images, such as cartoons or line drawings.
Resampling - A technique in digital image processing that interpolates pixels in the source data to new locations of transformed pixels, usually coinciding with a georeferenced grid.
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Georeference - The process of adding a real world coordinate system to a digital image. Accomplished in varying ways by viewing, CAD, or GIS systems.
In image processing, computer programs that remove distortion within a digital image, aerial photography or remotely sensed data by removing parallax errors due to relief (high ground being closer to the camera than low lying areas), camera tilt, ...
JPG (JPEG) JPEG (Joint Photographic Experts Group) Image format for continuous tone pictures: JPEG makes use of continuous-tone digital images much more economical by drastically reducing the volume required for storage and the bandwidth ...
Using different datasets stored in the same coordinate space allows you to see the relationships among different data. Image layers are used more and more as cheaper digital imagery becomes available.
5) It preserves as much of the source contour line data as is possible, thereby eliminating human digitizing error to a large degree. 6) It efficiently uses human intelligence for a task for which it is uniquely suited and for which digital image ...
 See also: Digital, Image, Information, GIS, Analysis
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