Draw rectangle

Works pretty much in the same way as the circles case, except that the given properties are different. You can now crop images and/or grids, change/move the rectangle and so on. Relatively hidden in these properties is the possibility of using the rectangle coordinates to register an image. This is more correct and gives more freedom to the user than the Map Limits option. The rectangle corner coordinates are used to compute an affine transformation that registers the image to the rectangle's coordinate system. To compute an affine transformation we need at least 3 points. With the rectangle we have 4, which is ok but imposes the unnecessary (to the affine transformation) restriction that the points lay on a rectangle. In fact, if you edit and change the rectangle to another shape, the registration option will no longer be available. From the rectangle properties you can also select the Transplant Image here. This non-finished tool allows selecting a second image that will be inserted inside the area enclosed by the rectangle. In its current state, the second image is always reinterpolated to fit the space (in terms of rows and columns) inside the rectangle. The crop tools options provide useful options that apply only to the grid elements contained in the rectangle. I wrote the spline smooth, median filter and fill gaps having in mind post processing of swath bathymetry grids, mainly to disguise the region of overlapping swaths. While this works pretty well (you may even work on shaded illuminated images) it has one drawback. It may leave a too clear suture zone between the processed and non-processed zones. This option has an experimental undo.

Copyright <2010>, <Joaquim Luis>

Created with the Freeware Edition of HelpNDoc: Easily create PDF Help documents