Conventions

This sections details Shareloc conventions for images and geometric models.

Pixel convention

Geometric model convention for coordinates is, by default, [0.5,0.5] at the center of the first pixel of the image, as illustrated below.

convention pixel — Fig. 2 pixel convention

Image convention

In Shareloc image convention, index refers to the position in the 2D array and Physical point the position of the pixel.

The transformation between index and Physical point use the geotransform of the image. OTB Software guide chapter 5.1 gives complete descriptions of these concepts.

Shareloc Image class (shareloc.image.Image) manages the conversion between index and physical point.

ROI can be easily managed without any processing on geometric model. See CARS Faq or GDAL translate command to create image extraction.

See image example in test directory for more details.