User:Balint.vanek/sandbox
From Wikipedia, the free encyclopedia
A távérzékelt képek centrális vetítéssel készülnek. A térkép és a legtöbb geoinformatikában alkalmazott vetületi rendszer viszont ortogonális vetülete a földfelszínnek. Ezek alapján centrális vetítésű képről a merőlegesre való áttérés, az ortorektifikáció vagy képhelyesbítés fogalma a következő: a távérzékelt perspektivikus képet vagy digitális képet perspektív torzulásoktól mentes képre, illetve digitális képre alakítjuk át.
This is the user sandbox of Balint.vanek. A user sandbox is a subpage of the user's user page. It serves as a testing spot and page development space for the user and is not an encyclopedia article. Create or edit your own sandbox here. Other sandboxes: Main sandbox | Template sandbox Finished writing a draft article? Are you ready to request review of it by an experienced editor for possible inclusion in Wikipedia? Submit your draft for review! |
A perspektivikus torzításoktól mentes képet ortofotónak, a digitális képet digitális ortofotónak nevezzük. Ha átalakítással párhuzamosan vetületi rendszerbe illesztés is megtörtént, akkor ortofotó-térképről illetve digitális ortofotó-térképről beszélünk.
An orthophoto, orthophotograph or orthoimage is an aerial photograph or image geometrically corrected ("orthorectified") such that the scale is uniform: the photo has the same lack of distortion as a map. Unlike an uncorrected aerial photograph, an orthophotograph can be used to measure true distances, because it is an accurate representation of the Earth's surface, having been adjusted for topographic relief,[1] lens distortion, and camera tilt.
Orthophotographs are commonly used in Geographic Information Systems (GIS) as a "map accurate" background image. An orthorectified image differs from "rubber sheeted" rectifications as the latter may accurately locate a number of points on each image but "stretch" the area between so scale may not be uniform across the image. A digital elevation model (DEM) is required to create an accurate orthophoto as distortions in the image due to the varying distance between the camera/sensor and different points on the ground need to be corrected. An orthoimage and a "rubber sheeted" image can both be said to have been "georeferenced" however the overall accuracy of the rectification varies. Software can display the orthophoto and allow an operator to digitize or place linework, text annotations or geographic symbols (such as hospitals, schools, and fire stations). Some software can process the orthophoto and produce the linework automatically.
Production of orthophotos was historically achieved using mechanical devices. [2]