Ortho

Previous  Top  Next

This module may be used to orthorectify photos.
The OrthoRECT module is destined to generate orthoimages basing on airphoto, photogrammetric project data and DTM file.

Input image
Having selected a project, select a photo and a model to read photo's exterior orientation elements from. Once you select a photo, you will see information about raster size and raster file name.

Using

button you select other raster file than indicated by the project.

Orthoimage parameters (Output image options)

Pixel size

Defines orthoimage pixel size in terrain unit. In this example each pixel's size is 0.5m

Tile size

Not used

Empty space color

Defines color of a surface not covered with a photo

File type

Output file type

TIFF - creates an uncompressed TIFstandard with an additional file with georeference information of TWF extension

INGR – creates an uncompressed file of INGR (Intergraph) standard

Pixel per line

Number of pixels per line in an output raster (to be filled in after selection of a DTM file)

Number of lines

Number of lines in an output raster (to be filled in after selection of a DTM file)

File name

You can define the output file's name

Digital Terrain Model data
Programme accepts dgr and grd format files

DGR	points grid file, you can create it in the DEPHOS software equipped with DTM Triangulation Module

GRD	points grid file, you can create it in the Intergraph's software

Remember that an orthoimage will be generated for the whole DTM area. Consequently an DTM file must be created for an area corresponding to a photo with margins.

After you select a file from DTM, a field with information about grid size and DTM ranges is filled in. Make sure that these values are reasonable in case of using GRD files, and correct the values in XYZ resolution and Global Origin fields, if necessary.
Information in XY and Z resolution and Global Origin X and Y fields are important if GRD files are used only. Their values are used to calculate file coordinates into terrain coordinates.

XY resolution = Master Unit * Position Unit
Z Resolution = Information given when GRD is being generated
Global Origin is the information you can get from Key In window using GO=? function.

Select [OK] button and the programme generates an orthoimage