After having successfully registered your images using MregCalculate(), you can extract the required results from your result buffer using MregGetResult().
You can retrieve general results for the entire registration calculation or specific results stored in the registration result elements. The registration result elements are indexed as positive integers, starting from 0, and correspond to the registration elements with the same index. For a complete description of all possible results, refer to the description of MregGetResult() in the MIL Reference.
Registration produces several types of results which provide information on the calculated positions for the images in the global pixel coordinate system and the success of the registration calculation. Results can be returned for:
Whether the registration was successful, globally or for an individual image (M_RESULT).
The score of the registration, globally or for an individual image (M_SCORE).
The X- and Y-coordinates of the origin of each image's pixel coordinate system in the global/reference coordinate system (M_POSITION_X and M_POSITION_Y).
The coordinates of the four corners of each image in the global/reference coordinate system (M_TRANSFORMED_...).
The identifier of the internal buffer that stores the forward or reverse transformation matrix, used to transform a position in an image into its position in the global/reference coordinate system or vice versa (M_TRANSFORMATION_MATRIX_ID, M_REVERSE_TRANSFORMATION_MATRIX_ID).
The forward or reverse transformation matrix data, used to transform a position in an image into its position in the global/reference coordinate system or vice versa (M_TRANSFORMATION_MATRIX, M_REVERSE_TRANSFORMATION_MATRIX).
The width and height that the mosaic will have when it is composed (M_MOSAIC_SIZE_X and M_MOSAIC_SIZE_Y). This information is useful to determine the size of the destination image buffer needed to hold the mosaic.
There are several ways that you can use the results of the registration. You can use them to create a mosaic with the images. For more information on mosaicing, see the Mosaicing section later in this chapter. Furthermore, you can use MregTransformCoordinate() or MregTransformCoordinateList() to convert a pair or a list of coordinates between two of the following coordinate systems: the global pixel coordinate system, an image's pixel coordinate system, or a mosaic's coordinate system. In addition, you can pass the retrieved identifier of the buffer containing the forward or reverse transformation matrix to MimWarp() and use it to warp other images.
Using the MregDraw() function, you can draw boxes in a destination image buffer or graphics list that outline the calculated positions (in the global pixel coordinate system) for the images. You can choose to draw in the display's overlay buffer. By drawing into the display's overlay buffer, you can annotate an image non-destructively (see the Annotating the displayed image non-destructively section of Chapter 21: Displaying an image).
You can use a previously allocated graphics context (see Chapter 22: Generating graphics) to control the drawing color, or use the default graphics context (M_DEFAULT).
You can also draw a zoomed version of the boxes that outline the images' positions. To do so, use MgraControl() with M_DRAW_OFFSET_X, M_DRAW_OFFSET_Y, M_DRAW_ZOOM_X, and M_DRAW_ZOOM_Y. The relative origin values must be specified in pixels and represent the coordinates in the mosaic's coordinate system that will appear at the top-left corner of the destination buffer. The scale values specify the X- and Y-scaling factors used to fill the destination buffer.