PHOTOMOD VectOr (raster images processing) - Racurs

PHOTOMOD
1.3.6. Horizontal alignment.
This operation causes placing selected raster points on one
horizontal line. The raster is rotated about the first selected point.
1.4. Raster region.
When loading raster images to the database there may be raster work region
created. To create raster region you should consequently load each raster image and
georeference them to the same coordinate system.
The combination of raster and vector maps for the same terrain districts is useful
for creating and updating work regions quickly. In this case you are able to resolve
application tasks related to raster and vector objects representations.
2. How to choose a type of raster transformation.
In case of creating of large-scale plans (layouts), it is recommended to use a
transformation by corner points of a map sheet (chapter 3.1).
When creating small scale digital maps (smaller than 1:50 000) in order to
increase the accuracy of the output raster image you should transform a raster image,
taken into account arch points of the map border (chapter 3.2).
If there is no map border on the raster image (or it exists partially), you can
transform raster by control point coordinates, which can be precisely recognized on
the image. The ground coordinates of control points (at least 4 points) must be known.
The other way is to transform a raster by two points with rotation and scaling (“Raster
list | Properties” menu). Besides, you can combine these two methods and make two
steps georeferencing (chapter 3.3).
If you about to create a raster map based on a raster image, mosaicked from
several fragments which are not images of standard nomenclature map sheets you
should use a method of consequent georeferencing of the raster image to the raster
map that already has a georeference. Act this way if for example a big source image
was scanned to overlapping portions (see chapter 3.4).
If you have a raster image of source photo-materials (airphotos or satellite
images) you can transform the source raster using a set of control points (chapter 3.5)
or control points along with exterior orientation parameters (chapter 3.6), depending
on what kind of corresponding information is available.
3. Recommendations for creating raster regions depending on
the type of source data.
3.1. Paper map with a rectangular border.
In this case the raster image is an image of a scanned paper map which border
does not have arch points (it is rectangular and consists of just four corner points).
Sheet corners should be precisely recognized on the raster image.
This kind of the transformation can be considered as a simplest one. You should
transform each raster using real values of map corners coordinates (stored in the
previously created map passport), cut the output image by the border of corresponding
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