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Image Regions

The image width and height represent the physical extent of the image. Hence it is assumed that the image begins at location (0, 0) and ends at (height, width). Images are indexed in the order row first and column second. The physical image usually begins at the top left hand corner and ends at the bottom right. It is this arrangement for which Tina will generate 3D geometrical primitives measured with respect to a right handed coordinate system.

Within the image the region field specifies the region of interest covered by the Imrect. The region is a pointer to the structure of type imregion

typedef struct imregion
{
    Ts_id ts_id;                /* Tina structure identifier */
    int     lx, ly;             /* top left */
    int     ux, uy;             /* bottom right */
} Imregion;

The region specified by the window structure covers the area (ly, lx) to (uy, ux) in image coordinates. Note that the region is allowed to lie outside (either wholly or partially) the underlying image area as defined by the width and height fields of the imrect data structure. It is useful in some circumstances to allow images to be transformed (eg. to allow for aspect ratio of the cameras or image warping) outside their original confines. In such cases height and width are used to indicate the size of the original image from which the deformed version was recovered.


next up previous contents
Next: Image Types Up: Imrects Previous: Imrects   Contents
root 2017-11-22