Abstract:
A system measures the three-dimensional linear, angular and volumetric characteristics of an animal or carcass, such as a beef animal. The system uses light spots from a structured light camera to measure multiple points on the animal. The system locates the vertical, horizontal and depth dimension for each point and uses this data to calculate the desired linear and volumetric measurements for conformation of the animal by combining measurements of some of the light spots projected on the animal. The system also provides rapid consecutive three-dimensional motion pictures of the animal.

Description:
FIELD OF THE INVENTION 
     This invention relates to a system for evaluating the physical characteristics of animals and more particularly to a structured light system for three-dimensional measuring. Even more particularly, the invention relates to projecting structured light toward an animal or carcass, measuring the reflection of the light from the animal or carcass, and using the measured light to develop a three-dimensional surface scan that can be used to measure both the linear, volume and angular related characteristics of the animal and provide rapid, consecutive images of an animal in motion. 
     BACKGROUND OF THE INVENTION 
     Throughout the history of the domestic livestock industry, mankind has attempted to measure animals, whether the need was to be taller, longer, thicker, leaner, wider or stronger, taking accurate measurements quickly has always been important. In modern times it has become more and more important to measure offspring of sires and compare those groups of offspring with like kind. Obviously, the sires that provide improved offsprings are in great demand and can provide the most improvement to a breed. Much of the future genetic progress will be attributed to our ability to improve the speed and accuracy of measuring animals. 
     Systems have evolved from measuring horses by using the approximate width of a hand; for example, a horse could be reported as 14 hands high which was about 56 inches. Currently some animals are measured at 15 different conformation points, however, most often the measurements are only visual appraisals, with even a tape measure being seldom used. Thus, there is tremendous need for more information and the improved accuracy of that information to accelerate breed progress. 
     One method of compiling data is shown in U.S. Pat. No. 4,745,472 issued May 17, 1988 to Hayes, entitled “Animal Measuring System”. This method uses a video camera to take a picture of the animal, and then the picture is processed by a computer system to determine the measurements. Plastic patches were placed on several points of the animal, and measurements were made of these points. Another method of compiling data is shown in U.S. Pat. No. 5,483,441 issued Jan. 9, 1996 to Scofield, entitled “System for Evaluation Through Image Acquisition” and U.S. Pat. No. 5,576,949 issued Nov. 19, 1996 to Scofield and Engelstad, also entitled “System for Evaluation Through Image Acquisition”. These systems use a conventional video camera, so they can only measure in two dimensions. Thus, in addition to the camera measurement, additional hand measurements usually need to be made, or the data from several cameras must be coordinated. Coordination of the data from several cameras is a difficult task, requiring manual interpretation by a skilled operator. 
     An additional method for compiling animal conformation is shown in U.S. Pat. No. 5,673,647 issued Oct. 7, 1997 to Pratt, entitled “Cattle Management Method and System.” This method, in part, explains the measuring of external animal dimensions. This method also measures using only two dimensions. 
     A three dimensional measuring system is shown in U.S. Pat. No. 5,412,420 issued May 2, 1995 to Ellis, entitled “Three-Dimensional Phenotypic Measuring System for Animals.” This system uses laser light signals to provide a three-dimensional measuring of linear and volumetric conformation traits of an animal, comparing those traits to predetermined traits and providing a rating of the animal. This system requires that the animal remain still during the laser scan of the animal. 
     It is thus apparent that there is a need in the art for an improved system which measures physical characteristics of an animal. There is further need in the art for such a system to measure in three dimensions. Another need is for such a system that does not require that patches be affixed to the animal before measuring. A still further need is for such a system that can measure in three dimensions using a single camera to provide linear, volume and angular measurements as well as improving the speed of imaging the animal. There is a further need for such a system that can provide rapid and consecutive three-dimensional images of an animal in motion. The present invention meets these and other needs in the art. 
     SUMMARY OF THE INVENTION 
     It is an aspect of the invention to measure physical characteristics of a live animal or carcass. 
     It is another aspect of the invention to measure the physical characteristics using reflected structured light. 
     Still another aspect is to measure the physical characteristics in three dimensions from a single camera. 
     Yet another aspect is to take rapid consecutive three-dimensional images of a moving animal. 
     Accurate three-dimensional information can be collected from a single location using reflected structured light. A three dimensional image is created by projecting a structured light pattern, for example wherein each element of the pattern is a circle of light and the circles are arranged in a grid pattern, a horizontal band or a vertical band of light, onto the animal and measuring the reflection of the elements of the pattern. The structured light from the animal is measured for differing distances by comparing the dimensions of the reflected structure light pattern elements on the animals to a known constant. 
     The pattern of circles is used to measure a predetermined number of locations on the animal, and the distance to each of these locations, thus creating a three-dimensional image of the animal. The radius of curvature of each of the circles can also be determined by the shape of each of the reflected circles. For example, an ellipse with an elongated vertical dimension indicates that the surface at the point of the ellipse is curving either away from the light source or toward the light source, and the length of the vertical dimension is used to determine the radius of curvature. The distance from the camera to the animal for multiple spots in the same vertical line indicates the direction of the curve, that is, whether the curve is concave or convex. This same concept is also used for horizontal patterns of circles to determine the radius of curvature in the horizontal direction, as well as whether the curve is concave or convex. 
     Because animals are symmetric, an image need only be taken of one side of the animal. Thus a single camera at a single location provides all the three-dimensional information necessary for conformation of an animal. With some breeds, such as dairy cows, it may be necessary to use a second camera or take a second image of hidden areas; for example, a dairy cow may need a second image of the mammary system as viewed from the rear to provide additional accuracy for that portion of the animal. 
     A computer system selects the points of the animal desired for the conformation, measures the distance between these points to provide the conformation data, combines the selected conformation data for each animal with an identification number, and stores the conformation data and number for each animal. In addition, an image of the animal, showing the markings of the animal, may be stored along with the other conformation data. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other aspects, features, and advantages of the invention will be better understood by reading the following more particular description of the invention, presented in conjunction with the following drawings, wherein: 
     FIG. 1 shows a view of the present invention measuring and compiling data of an animal; 
     FIG. 2 shows a single linear latitude cross section (horizontal end view) of an animal to illustrate a portion of the image process of structured light signals; 
     FIG. 3 shows a single linear longitude cross section (overhead view) of an animal to illustrate a portion of the image process of structured light signals; 
     FIG. 4 shows a block diagram of the present invention; 
     FIG. 5 shows a view of a structured light camera projecting circle patterns at varying distances; 
     FIG. 6 shows a block diagram of a structured light camera; 
     FIG. 7 shows an animal with a vertical stripe pattern projected thereon; and 
     FIG. 8 shows an animal with a grid pattern of vertical and horizontal striped pattern elements projected thereon. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description is of the best presently contemplated mode of carrying out the present invention. This description is not to be taken in a limiting sense but is made merely to describe the general principles of the invention. The scope of the invention should be determined by referencing the appended claims. 
     A three-dimensional image of an animal or carcass is created by projecting a structured light display onto the animal and measuring the reflection of the display. The reflected structured light from the animal can be measured for differing distances by comparing the diameter (width) of the reflected structured light display on the animals to a known constant. The sources of light are projected through a lens or lenses that control the light to provide a very slight increase in the diameter of the numerous source spots or bands as the light moves away from the source. 
     For example, a single circular beam of structured light can be created by placing a hole in a planar surface, such as a thick paper or metal card, next to a light source. A lens in front of the planar surface is used to focus the circular spot created by the hole to within a 6 to 8 foot range. The lens is used to adjust the diameter of the circular spot to be 1.5 inches at 6 feet. The diameter of the spot will then be 1.75 inches at 7 feet, and the diameter will be 2.0 inches at 8 feet. The distance (z-axis) to the reflected spot can then be calculated, within this 6 foot to 8 foot range, by measuring the diameter of the reflected circular structured spot. A three-dimensional measurement is then achieved by measuring the x-axis, and y-axis locations for the structured light spot. 
     Using a grid pattern of circular structured light spots, the dimensions of the animal can be determined from the midsection of an animal upward towards the back bone (top) as the animal curves away from the source. As described above, a beam that lands on a vertical surface (or nearly vertical) creates a circle of reflected light. Another spot that reflects from a higher location on the animal, where the surface is curving away from the source, will reflect an ellipse, elongated in the vertical direction. As the degree of angle from vertical increases, the length of the elongated shape increases proportionally. The position of the x-axis and y-axis for the spot are still at the center of the elongated spot. However, the depth (z-axis) has moved and can be calculated by the using the shorter diameter of the two axes of the spot as the diameter of a circle. The same concept is true for elongated structured light reflections on the front, rear, or belly of the animal. 
     If the originating light source holes in the grid are set in rows at equal distance apart and consecutive rows are at equal distances, then the structured light display on the animal will provide a consistent pattern of spots. The resolution of the display image can be varied by the number of holes used to structure the light at the source. For example, a tall and narrow structured light display (approximately seven feet tall by three feet wide) can be used to measure a hanging beef carcass. Changing of the focus point of the spots can vary the distance to the animal of the structured light display to accommodate larger or smaller animals. 
     After receiving the structured light display, computerized calculations of each image are made to create a three-dimensional surface model of the animal. The head and tail can be, but are usually not included in the surface model because they are not normally measured. The head on some occasions may be obstructed from view by a stanchion or head lock apparatus in a chute. 
     A high speed camera or video camera can be used to receive the structured light display image from the animal. By creating a succession of images, movement characteristics of the animal can be measured. While a continuous source of structured light is typically used, a flash or consecutive flashes of structured light projected toward the animal and coordinated with the camera can also be used to create a three dimensional moving image or motion picture of the animal. By creating a series of pictures, the system can also select the best of the series of pictures for use. 
     FIG. 1 shows the system of the present invention that measures three-dimensional phenotypic characteristics of an animal using a structured light camera. Referring now to FIG. 1, the animal  108  shown in FIG. 1 is a beef animal, standing in front of the structured light camera  132 . The beef animal  108  can be free standing, tied, in a stanchion or in a chute. The camera  132  generates a detailed map of the entire animal within the scanned space assigning range values to each surface point that receives a structured light pattern element. The tripod  134  can be used for the structured light camera  132  or the camera can be hand held or set on a table. Typically, there are 900 surface points, called pattern elements, in the field of view of the camera  132 , however the number of pattern elements can be increased or decreased depending upon the structure light means used as the source. FIG. 1 does not contain sufficient detail to illustrate all surface points, so the lines  111  represent the number of structured light signals that would cover the entire animal. 
     An electrical source (not shown) provides electric power for the camera  132 , personal computer  136  and the printer  128 . In a remote environment, this electrical source can be provided by a portable generator or batteries. Connecting data cable  140  transmits the information from the camera  132  to the personal computer  136 . A telephone modem  130  and wires  126  and  127  can be used to transmit data from the personal computer  136  to a main frame computer  120  and back to printer  124 . A local printer  128  could also be used to print the data. 
     When the horizontal, vertical and distance dimensions of two points on the animal are provided by the camera  132  measurements, then the difference between those two points can easily be computed. See, for example, U.S. Pat. No. 5,412,420 issued May 2, 1995 to Ellis, entitled “Three-Dimensional Phenotypic Measuring System for Animals”, incorporated herein by reference for all that is disclosed and taught therein. By measuring hundreds of points on the animal, the system calculates hundreds of different measurements. The system also calculates the volume of the barrel, loin muscle and round muscle (rear hind quarter) of the animal. One particular advantage of the structured light measurements is that the system can calculate the distance to the animal, thus avoiding inaccuracies of some prior art camera systems when the animal is placed at an incorrect distance from the camera. 
     FIG. 2 shows a side cross section view of the animal along with the measuring system to illustrate the three-dimensional measurements of the animal. Referring now to FIG. 2, the animal is shown with the side away from the camera  132  in dotted lines. The camera  132  scans a line of the animal from the top of the animal, i.e.  106  of FIG. 1, to the floor or ground. This example helps visualize the concept of the structured light signals  111  as they measure distance to each surface point. 
     FIG. 3 shows a top view of the animal and the structured light signals  111 , wherein the side of the animal opposite the camera  132  is shown in dotted lines. Referring now to FIG. 3, the camera  132  scans a line of the animal from the front of the body of the animal to the rear of the animal  108  in FIG.  3 . The opening  142  in camera  132  receives the reflected structured light. This example helps visualize the concept of the structured light signals  111  as they measure the distance to each point on the animal. 
     FIG. 4 shows a block diagram of a computer system and the structured light camera of the present invention. Referring now to FIG. 4, the computer system  136  contains a processing element  402 . The processing element  402  communicates to the other elements of the computer system  136  over a system bus  404 . A keyboard  406  and a structured light camera  132  allow input to the computer system  136 . A mouse  410  provides input for locating specific points on the image of the animal as displayed on graphics display  408 , which also provides a display of any other information to be viewed by a user of the computer system  136 . A printer  128  allows for output to paper to be viewed by a user of the computer system  136 . A disk  412  stores the software and data used by the system of the present invention, as well as an operating system and other user data of the computer system  136 . 
     A memory  416  contains an operating system  418 , and an application program  420 , a phenotypic measuring system for animals. Those skilled in the art will recognize that the operating system  418  could be one of many different operating systems, including many windows-type operating systems, and that many application programs could be performing in a multi-tasking operating system. 
     FIG. 5 is a diagram illustrating how distance is measured using structured light. Referring to FIG. 5, a structured light camera  132  includes a projection system (shown below in FIG. 6) that projects a pattern of circular spots that are all the same size when they leave the projection system, as illustrated by light rays  111 . Three boxes  502 ,  504 , and  506  are arranged at successively greater distances from the structured light camera  132 . 
     A spot  510  strikes box  502  and this spot has a fixed diameter. A second spot  512 , which strikes box  504  further away from the camera  132 , has a fixed diameter larger than the diameter of spot  510 . This larger diameter spot indicates that the surface  520  on which the spot  512  is projected is further away from the camera  132  than is the surface  518  on which spot  510  is projected. Similarly, spot  514  has a still larger diameter, indicating that the surface  524  is still further away from the camera  132  than is either surface  520  or surface  518 . 
     After calibration and measurement of the size of the spots  510 ,  512 , and  514 , the distances of the surfaces  518 ,  520  and  524  from the camera  132  can be determined. 
     Surface  508  is canted back from the vertical, and therefore spot  516  forms an ellipse on the surface  508 . The center of the ellipse is the same as the center of a circular spot would be if the surface  508  were vertical. The diameter of the horizontal dimension of the ellipse can be used to measure the distance to the center of the ellipse, and the length of the vertical dimension of the spot  516  can be used to determine the angle at which the surface  508  is canted from vertical. The horizontal dimension of spot  516  will be the same as the horizontal dimension of a circular spot located at the same distance from the camera  132  if the surface  508  is perpendicular to the beam  111 . If the horizontal dimension of the spot  516  is elongated, than the surface  508  is not perpendicular to the beam  111 . Thus, the shape of the spots  510 ,  512 ,  514 , and  516  is used to indicate both the distance from the camera  132  and the angle of the surface on which the spots are projected. 
     FIG. 6 shows a block diagram of a structured light camera, as used in the present invention. Referring to FIG. 6, a structured light camera  132  is shown having a projection system  602  and a light receiving system  604 . The light receiving system  604  is typically a conventional video camera (not shown), but could be any other type of camera, having a lens opposite an aperture  142 . The aperture  142  merely serves to limit the field of view of the video camera and may not be necessary with some cameras. 
     The projection system  602  is similar to a conventional slide projector and it projects the structured light pattern. A lamp  606 , connected to a suitable electrical source  610 , provides illumination. Vents  608  cool the lamp  606  and lenses  612  and  614  condense the light from lamp  606  and provide a heat shield to prevent heat from the lamp  606  from altering the shape of the structured light pattern slide  616 . The pattern slide  616 , which is interchangeable, is used to create the pattern of circles, horizontal stripes or vertical stripes, etc. After the light from lamp  606  passes through the pattern slide  616 , it is focused by lens  618  to the approximate distance of the animal. 
     FIG. 7 shows an animal with a plurality of vertical stripe pattern elements being projected thereon, for example elements  702 ,  704  and  706 . Using vertical stripe pattern elements allows continuous distance data to be determined along the vertical axis. A similar pattern of horizontal pattern elements can also be projected upon the animal. 
     Continuous distance data can be acquired in both vertical and horizontal directions by using both these patterns in two separate images. This is done by projecting a vertical pattern, capturing an image of the vertical pattern, then projecting a horizontal pattern and capturing an image of the horizontal pattern. Both these images are then processed to produce continuous vertical and horizontal distance data. By creating both the images in rapid succession, any error caused by movement of the animal is reduced. 
     FIG. 8 shows an animal with a combination of vertical pattern elements, for example elements  802 ,  804 , and  806 , and horizontal pattern elements, for example elements  808 ,  810 , and  812 , projected thereon. This type of pattern provides nearly continuous horizontal and vertical distance data while allowing both vertical and horizontal patterns in a single image. 
     While the general inventive concepts and systems have been described in connection with illustrative and presently preferred embodiments thereof, it is intended that other embodiments of these general concepts and systems be included within the scope of the claims of this application and any patent issued therefrom. It is contemplated that use of the present system will enable an enhanced knowledge with respect to the correlation between measurable characteristics and traits of carcasses or animals and their offspring. While the general concepts and systems of the invention have been illustrated and described by reference to a particular kind of animal, i.e., beef animal, it is to be understood and it is contemplated that the general concepts may be applied to other kinds of animals or animal carcasses, such as dogs, pigs, dairy cattle, horses, chickens, etc. and human beings for any worthwhile purpose.