What is digital photogrammetry?
In general, digital photogrammetry is art using computers to get objects in the photo. It usually includes an analysis of one or more existing photos or videos with photogrammetric software to determine spatial relationships. Although commonly used to create topographic maps, it can also be useful in various industries such as architecture, production, police investigation and even plastic surgery. First, it may be useful for a photogrammetrist to know the camera information, for example what type of camera has taken a photo, focal lens length, or camera distance to an object of interest. To take these photos, a special type of camera called a metric camera is often used because it is calibrated to take accurate photos with little lens distortion.
The second variable that needs to be considered in digital photogrammetry is the desirdimension of measurement. Some projects require only two -dimensional (2D) measurements such as building heighty or the width of the river. These measurements can be made from one photo. However, if the measurement must be three -dimensional (3D), the process will usually include the creation of a 3D model from two or more photos.
This process of creating a 3D model is usually called digital stereophotogrammetry. Stereophotrammetrists usually analyze two or more photos of the same object taken from different angles. They usually use space where photos overlap or general reference points shared photos to create a digital 3D model. Pictures can then be mapped, pixels with a pixel in the model to create a measurable space in three dimensions.
The third variable is the type of photos used. Usually, use digital photos or video. Movie photos and videotapes usually have to be scanned to a computer to be used in digital photogrammetry.
two headsThe photos category are aerial and close. Air digital photogrammetry, often used in topographic mapping, begins with digital photographs or video taken from a camera mounted on the bottom of the aircraft. The aircraft often flies through an area in a meandering flight path, so it can take overlapping photographs or video from the whole area to get complete coverage.
Digital photogrammetry with tightness or ground or ground range often uses photographs taken from close proximity to hand -held cameras or on a tripod. Photos of close range can be used to create 3D models, but are usually not used in topographic mapping. This type of photogrammetry is useful for 3D modeling of many objects or areas such as buildings, car accidents or sets of movies.