Transform raster map

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rswtrans64 The task «Transform raster map» is intended for transformation of a raster map into output coordinates system by a set of points. Coordinates of points are measured or are loaded from catalogs of coordinates. Point measurements can be performed in single-window or double-window mode.

If the raster is already snapped to the map, but has minor offsets, then it is more convenient to perform measurements in one window. In this case, the raster and the map must be open in the same window before starting the task.

If a raster is snaped to another raster or to a map that is significantly displaced or rotated relative to the raster, then it is more convenient to perform measurements in two windows. In the main window that was active when the task was started, a raster to be transformed must be open. Points in the output coordinate system are measured on a vector or raster map in an additional window. An additional window is selected from the list «Output coordinates are measured on the map».

The list of additional maps is filled at start of the task and automatically is updated at opening and closing additional maps. After start of the task to open an additional map it is possible both by standard means of the GIS Panorama and by pressing the button to the right of the list «Output coordinates are measured on the map». Moving the focus between the main and additional windows is performed automatically when moving the mouse.

In the task four linear and three nonlinear transformation methods have been implemented.

 

rswtrans_engbm1882

 

To determine the parameters of transformation it is necessary:

- select a transformable raster from the list of open rasters;

- specify a name of output raster;

- specify the element size of an output raster. If the button is clicked, the size of an element is calculated automatically by the size of an element of an input raster multiplied by the scale factor calculated on coordinates of control points;

- choose type of interpolation;

- select the transformation method ;(see)

- specify catalogs of coordinates of control points in the input and output coordinate system or to measure the points on the input and additional map (the map for the measurement of points in the output coordinate system). Points in the output coordinate system can be downloaded from the border of sheet, kilometer grid (code 13210000, 13220000) or the selected objects by clicking the "Output coordinates add from ...";

- if necessary to install advanced options.

Recalculation of parameters of transformation is carried out automatically at measurement of points or at change of transformation parameters. By results of calculation of parameters of transformation the residual differences and a mean-square error are displayed. After calculation of transformation parameters it is possible to execute at once transformation, having pressed button "Transform", or for the analysis of nonlinear distortions to build matrixes of distortions by pressing the button «Build matrix».  By results of transformation the protocol with prt extension in a folder of the transformed map is created.