JPH04291679A - Device for discriminating grade of tuna - Google Patents

Abstract

PURPOSE:To objectively discriminate the freshness and fat contents of tuna. CONSTITUTION:This tuna grade discriminating device is constituted of a white lamp 16 which the section of a tuna slice 12 is irradiated with white light, a black-and-white ITV camera 18 for photographing the slice 12, a differential emphasis circuit device 22 for differentially emphasizing a black-and-white video signal outputted from the camera 18 and converting the video signal into a binary image, a color ITV camera 24 for photographing the slice 12, a color extracting circuit device 28 for extracting the video signal of only a specific color component out of an image photographed by the camera 24 and converting the video signal into a binary image, an arithmetic circuit device 30 for executing AND operation between the binary images outputted from the devices 22, 28, and a measurement circuit device 38 for measuring the area, shape, etc., of the image computed by the circuit 30.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuna grading device, and more particularly to a tuna grading device for evaluating the freshness and fat content of tuna.

0002

2. Description of the Related Art Conventionally, tuna has been judged visually. In other words, a skilled inspector judges the freshness of the tuna based on the sharpness (contrast) of the scale marks (white striped patterns distributed approximately concentrically around the spine) found on the cut surface of the tuna.
The total fat content of the tuna body is estimated and determined based on the distribution of oil (fat content) on the cut surface.

[0003] In the freshness determination, the clearer the scale pattern, the better the freshness, and the higher the fat content, the higher the rank.

0004

[Problems to be Solved by the Invention] However, since the conventional judgment of tuna is performed by visual estimation, there is a drawback that it is not possible to objectively rank and judge tuna using numerical values. In order to solve this problem, there is a method of measuring fat distribution using near-infrared rays, but this method has not been put into practical use.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a tuna grade discriminating device that can objectively and numerically judge the freshness and fat content of tuna.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an illumination device for illuminating the cut surface of the tuna, a black and white imaging camera for photographing the cut surface of the tuna, and a black and white imaging camera for photographing the cut surface of the tuna. A differential emphasis circuit that differentially emphasizes a video signal and converts it into a binary image, a color imaging camera that photographs the cut section of the tuna, and a video signal that shows only specific color components of the video captured by the color imaging camera. a color extraction circuit that extracts the video signal and converts the video signal into a binary image; an arithmetic circuit that performs an OR operation on the binary image of the differential emphasis circuit and the binary image of the color extraction circuit; It is characterized by comprising a measurement circuit that measures the area, shape, etc. of the image calculated by the circuit.

[0007]

[Operation] According to the present invention, the freshness of tuna is determined by image processing using the contrast difference between the scale pattern and other parts on the cut surface, and the fat content is determined on the cut surface. This is done by image processing using the difference in color between fat parts and other parts of the body.

That is, the freshness of tuna can be determined by using two differential emphasis circuits.
The digitized image and the binarized image from the color extraction circuit are logically ORed by an arithmetic circuit, and the area, shape, etc. of the calculated image are measured by a measuring circuit, and based on the obtained area, shape, etc. judge. In addition, the fat content is determined by extracting a video signal showing only the color component corresponding to the fat content color from the video captured by a color imaging camera, and then binarizing the extracted video signal showing the fat content. , find the area of this binarized image, find the area ratio in the total area of the cut plane, and make a determination based on this ratio.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the tuna grade discriminating apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the tuna grade discriminating apparatus 10 according to the present invention, in which a tuna fillet 12 is placed on a sample stage 14 with the cut side facing upward. As shown in FIG. 2, this fillet 12 has fat 13 in the lower part (abdomen), and white streak-like scales 15 are distributed approximately concentrically around the vertebrae 12a.

A pair of white lamps 16, 16 are placed above the tuna fillet 12, as shown in FIG. can do. Further, a black-and-white ITV camera 18 is installed at a position where it can image the cut surface of the fillet 12. A differential enhancement circuit device 22 is connected to the monochrome ITV camera 18 via a cable 20, and the differential enhancement circuit device 22 extracts an image corresponding to the contrast of the scale pattern 15 from the monochrome video signal inputted from the monochrome ITV camera 18. The signal can be extracted and converted into a binarized image.

[0011] Furthermore, the color ITV camera 24
It is installed at a position where it can image the cut plane of the camera, and at a position where the images taken by the black-and-white ITV camera 18 have the same positional relationship. The color ITV camera 2
4 is connected to a color extraction circuit device 28 via a cable 26. The color extraction circuit device 28 extracts a light pink video signal corresponding to the color of the fat 13 of the fillet 12 shown in FIG. 2 from the color video signal input from the color ITV camera 24, and converts this video signal into two It can be converted to a valued image.

On the other hand, the arithmetic circuit device 30 is connected to the cable 32,
It is connected to the differential emphasis circuit device 22 and the color extraction circuit device 28 via 34. This arithmetic circuit device 30 is configured to perform each two steps obtained by the differential emphasis circuit device 22 and the color extraction circuit device
It is possible to perform a logical product operation on valued images. Further, a measurement circuit device 38 is connected to the arithmetic circuit device 30 via a cable 36 . This measurement circuit device 38 can measure the characteristic quantities such as the area and shape of both images calculated by the arithmetic circuit device 30.

Next, the operation of the tuna grade discriminating device constructed as described above will be explained. First, in order to judge the sharpness from the scale pattern 15 (in FIG. 2), which is an index for judging the freshness of tuna, first, the black and white video signal from the black and white ITV camera 18 is differentially emphasized (bright and dark) by the differential emphasis circuit device 22. This image is then binarized to create the binarized image shown in FIG. 3(a). The binarized image is scale pattern 1
In addition to 5, the image includes the unevenness of the cut surface and the boundary between the skin and the flesh, so it is difficult to judge the sharpness of only the scale pattern 15 from this image. Therefore, out of the color video signal from the color ITV camera 24, only the white color of the scale pattern 15 is extracted by the color extraction circuit device 28 and subjected to binarization processing to create the extracted image shown in FIG. 3(b). Next, when both the images shown in FIGS. 3(a) and 3(b) are subjected to an AND operation by the arithmetic circuit device 30, the extracted image of only the scale pattern 15 is changed as shown in FIG. 3(c) according to the degree of contrast. appears in Next, the area and shape of the scale pattern 15 in this extracted image (length, width, etc. of the scale pattern 15)
etc. are measured by the measurement circuit device 38. Then, the visibility is determined based on this measured value, and the freshness is determined based on the determined visibility. This makes it possible to judge the freshness of tuna using objective numerical values.

Next, the determination of the fat content of tuna will be explained. First, out of the color video signals from the color ITV camera 24, only the light pink video signal of the fat 13 is extracted by the color extraction circuit device 28, and then this video signal is binarized and shown in FIG. 4(a). Create the binarized image shown. Since the binarized image is an image in which only the fat 13 portion is extracted, the ratio of fat area to the total area of the cut surface cannot be determined from this image. Therefore, the image shown in FIG. 4B is created by expanding the color setting range using the color extraction circuit device 28 so as to display the entire cut surface. Then, the measurement circuit device 38 measures the ratio of the binarized image area shown in FIG. 4(a) to the image area shown in FIG. 4(b). Thereby, the fat 13 can be determined using an objective numerical value.

[0015]

[Effects of the Invention] As explained above, the tuna grade discriminating device according to the present invention utilizes the contrast difference between the scale pattern and other parts of the cut surface of the tuna and the color of the scale pattern. The freshness of the tuna is determined by extracting the scale pattern by image processing, and the fat part is extracted by image processing using the difference in color between the fat part and other parts of the cut surface. Since the fat content is determined based on the method, the freshness and fat content of the tuna can be determined using objective numerical values.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the tuna grade discrimination device according to the present invention.

FIG. 2 is an explanatory diagram of a cut surface of tuna.

[Figure 3] Explanatory diagram showing an image processing method for determining the freshness of tuna

[Figure 4] Explanatory diagram showing an image processing method for determining the fat content of tuna

[Explanation of symbols]

10...Tuna grade discrimination device 12...Tuna fillets 16...White lamp 18...Black and white ITV camera 22... Differential emphasis circuit device 24...Color ITV camera 28...Color extraction circuit device 30...Arithmetic circuit device 38...Measuring circuit device

Claims (3)

[Claims] Claim 1: An illumination device that illuminates the cut surface of the tuna, a monochrome or color imaging camera that photographs the cut surface of the tuna, and a monochrome video signal obtained from the monochrome camera that is differentially enhanced and converted into a binary image. A differential emphasis circuit, a color imaging camera that photographs the cut surface of the tuna, and a video signal showing only a specific color component from the video captured by the color imaging camera is extracted and the video signal is converted into a binary image. an arithmetic circuit that performs an AND operation between the binarized image of the differential emphasis circuit and the binarized image of the color extraction circuit, and measures the area, shape, etc. of the image computed by the arithmetic circuit. A tuna grade discriminating device characterized by comprising: a measuring circuit for detecting tuna; 2. The specific color is a color corresponding to a white striped pattern called a scale pattern that is distributed in many layers in substantially concentric circles, and the image calculated by the calculation circuit includes only the extracted scale pattern. 2. The tuna grade discriminating device according to claim 1, wherein the tuna grade discriminating device is an image shown in FIG. 3. A second color extraction circuit that extracts a video signal showing only the color component of tuna oil from the video imaged by the color imaging camera and converts the video signal into a binary image; , and a second measurement circuit that measures the area, distribution amount, etc. of the binarized image extracted by the second color extraction circuit.