DischargeLab is a full suite for calculating discharge via sequence of images or videos, it guides the user through all the needed steps for obtaining the discharge, from importing the Ground Control Points (GCP) and cross section (XS) to obtaining the discharge. Several steps are done in the way, like camera calibration, distortion removal, orthorectification, optical water level detection, surface velocimetry (using SSIV or STIV) and and discharge calculation.
Easy import of GCP and XS. GCP's and XS can be imported from external files. Both input data must be in the same reference system, however this is not always the case, DLab offers an easy interface to move and rotate them.
Camera calibration. In order to transform between image and world coordinates it is necessary to calibrate the camera. DLAb offers a very flexible way for camera calibration, it can calibrate any camera even cameras mounted on UAV's. You can use 6 or more GCP, or you can use 4 GCP and the camera position or orientation, or when parallel shores are available simply select an isolevel. During the calibration process DLab also corrects for any radial distortion.
Surface velocity in pixels/frame. It is possible to get the surface displacement even without calibrating the cameras, DLab can calculate the 2D surface velocity flow in image space, the only input needed is a video.
Detailed surface velocity flow in meters/second. If in addition to the video, the camera has been calibrated, it is possible to measure a detailed 2D surface velocity field in metric units.
Optical measurement of the water level. DischargeLab can measure the water level optically, there is no need of having a staff gauge, but a well define plane is needed.
Discharge calculation. Combining the information of the water level, with the surface velocity and the cross section, DLab can calculate the discharge. To do this, it is also necessary to calculate the bulk velocity, DLab has several models to do perform this task.
SSIV and STIV. The default algorithm to calculate the surface velocity is SSIV, however DLab can also use STIV for the surface velocity calculation.
Batch processing and data analysis. Do you have many videos from the same site? DLab can process them in a batch with only one click.