gen_arbitrary_distortion_mapT_gen_arbitrary_distortion_mapGenArbitraryDistortionMapgen_arbitrary_distortion_mapGenArbitraryDistortionMapGenArbitraryDistortionMap (Operator)

Name

gen_arbitrary_distortion_mapT_gen_arbitrary_distortion_mapGenArbitraryDistortionMapgen_arbitrary_distortion_mapGenArbitraryDistortionMapGenArbitraryDistortionMap — Generate a projection map that describes the mapping between an arbitrarily distorted image and the rectified image.

Signature

Description

gen_arbitrary_distortion_mapgen_arbitrary_distortion_mapGenArbitraryDistortionMapgen_arbitrary_distortion_mapGenArbitraryDistortionMapGenArbitraryDistortionMap computes the mapping MapMapMapMapMapmap between an arbitrarily distorted image and the rectified image. The coordinates RowRowRowRowRowrow and ColumnColumnColumnColumnColumncolumn describe a distorted grid, which will be mapped onto a regular grid in the rectified image. The coordinates of the (distorted) grid points must be passed line by line in RowRowRowRowRowrow and ColumnColumnColumnColumnColumncolumn. GridWidthGridWidthGridWidthGridWidthGridWidthgridWidth is the width of the point grid in grid points. GridSpacingGridSpacingGridSpacingGridSpacingGridSpacinggridSpacing is the distance between two adjacent grid points in the rectified image. Because the grid points are always mapped to the centers of their corresponding pixels a grid cell requires (GridSpacingGridSpacingGridSpacingGridSpacingGridSpacinggridSpacing+1) x (GridSpacingGridSpacingGridSpacingGridSpacingGridSpacinggridSpacing+1) pixels in the rectified image. Note however, that, of course, adjacent grid cells overlap by one pixel.

To compute the mapping MapMapMapMapMapmap, additionally the width ImageWidthImageWidthImageWidthImageWidthImageWidthimageWidth and height ImageHeightImageHeightImageHeightImageHeightImageHeightimageHeight of the images to be rectified must be passed.

MapTypeMapTypeMapTypeMapTypeMapTypemapType is used to specify the type of the output MapMapMapMapMapmap. If 'bilinear'"bilinear""bilinear""bilinear""bilinear""bilinear" interpolation is chosen, MapMapMapMapMapmap consists of one image containing five channels. In the first channel for each pixel in the resulting image the linearized coordinates of the pixel in the input image is stored that is in the upper left position relative to the transformed coordinates. The four other channels contain the weights of the four neighboring pixels of the transformed coordinates which are used for the bilinear interpolation, in the following order:

The second channel, for example, contains the weights of the pixels that lie to the upper left relative to the transformed coordinates. If 'coordinate_map_sub_pix'"coordinate_map_sub_pix""coordinate_map_sub_pix""coordinate_map_sub_pix""coordinate_map_sub_pix""coordinate_map_sub_pix" is chosen, MapMapMapMapMapmap consists of one vector field image, in which for each pixel of the resulting image the subpixel precise coordinates in the input image are stored.

As mentioned above, four adjacent pixels in the destorted image are required to interpolate the gray value of one pixel in the mapped image. If at least one of these pixels is located outside of the distorted image the gray value can not be calculated. The domain of the resulting MapMapMapMapMapmap domain is reduced accordingly.

In contrary to gen_grid_rectification_mapgen_grid_rectification_mapGenGridRectificationMapgen_grid_rectification_mapGenGridRectificationMapGenGridRectificationMap, gen_arbitrary_distortion_mapgen_arbitrary_distortion_mapGenArbitraryDistortionMapgen_arbitrary_distortion_mapGenArbitraryDistortionMapGenArbitraryDistortionMap is used when the coordinates (RowRowRowRowRowrow,ColumnColumnColumnColumnColumncolumn) of the grid points in the distorted image are already known or the relevant part of the image consist of regular grid structures, which the coordinates can be derived from.

If you want to re-use the created map in another program, you can save it as a multi-channel image with the operator write_imagewrite_imageWriteImagewrite_imageWriteImageWriteImage, using the format 'tiff'"tiff""tiff""tiff""tiff""tiff".

Parallelization

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Processed without parallelization.

Parameters

Result

gen_arbitrary_distortion_mapgen_arbitrary_distortion_mapGenArbitraryDistortionMapgen_arbitrary_distortion_mapGenArbitraryDistortionMapGenArbitraryDistortionMap returns 2 (H_MSG_TRUE) if all parameter values are correct. If necessary, an exception is raised.

Possible Successors

map_imagemap_imageMapImagemap_imageMapImageMapImage

See also

create_rectification_gridcreate_rectification_gridCreateRectificationGridcreate_rectification_gridCreateRectificationGridCreateRectificationGrid, find_rectification_gridfind_rectification_gridFindRectificationGridfind_rectification_gridFindRectificationGridFindRectificationGrid, connect_grid_pointsconnect_grid_pointsConnectGridPointsconnect_grid_pointsConnectGridPointsConnectGridPoints, gen_grid_rectification_mapgen_grid_rectification_mapGenGridRectificationMapgen_grid_rectification_mapGenGridRectificationMapGenGridRectificationMap

Module

Calibration