JP2009232942A - Method for analyzing gravity center position - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for analyzing a gravity center position accurately, quickly, and easily by using sole image data. <P>SOLUTION: The soles of the feet are mounted on a transparent body which projects light inside. Color components of right and left sole image data acquired by imaging the soles from the rear side are converted from RGB values to HSV values, and sole grounded part images are extracted by means of a threshold value. Color components of the extracted sole grounded data are then converted from HSV values to RGB values. The product of a luminance value and a coordinate axis is acquired for each pixel, and the sum of the products of all pixels are acquired. The acquired sum is then divided by the sum of all luminance values of the RGB values of the sole grounded image data. By doing so, the gravity center position of a subject is analyzed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for analyzing the position of the center of gravity when standing on both feet in order to inspect the standing posture and health condition of a measurement subject.

  Generally, it is said that the load distribution on the left and right feet varies depending on postures such as human head tilt and spinal column twist, and is closely related to health.

  Therefore, by measuring the load applied to the left and right feet and the position of the center of gravity, it is possible to know the abnormal posture and health of the body.

  Conventionally, a balance measuring device is disclosed in Japanese Patent Laid-Open No. 10-192259 as a device for measuring the load applied to the left and right feet and the position of the center of gravity. This device is divided into small sections of a certain size, each of which has a pressure sensor sheet that can measure the load independently, processes the detected signal and outputs it to the data output unit as an image or numerical value It consists of a data processing unit.

  As a result, the pressure sensor sheet according to the present invention can detect the load for each of the small sections, whereby the load distribution on the sole, the size of the foot, the degree of formation of the arch, and the position of the center of gravity for each foot are detailed. Can be measured.

  Japanese Patent Publication No. 50-16919 is described as a method for measuring the center of gravity. This is because the object to be measured is contacted and supported on a measuring body made of a translucent body, light is projected onto the transparent body and diffusely reflected on the grounding surface of the body to be measured, and the grounding surface of the body to be measured is grounded to the measuring body. The center of gravity of the object to be measured that is projected as an image and applied to the measuring body is detected by a load sensor, and the ground contact image and the center of gravity are overlapped.

  Thus, the present invention can clearly observe the position of the center of gravity and its movement together with the soles.

In addition, as a method for measuring the plantar pressure distribution, there is a pressure / light conversion method. This is because the subject stands on a measuring table made of tempered glass, the tempered glass is illuminated by light sources installed on the two sides facing each other, and the upper surface of the tempered glass is covered with a thin film or a rubber or plastic mat. The sole is photographed from below, and the photographed image is captured by a personal computer and displayed on a display.
Japanese Patent Laid-Open No. 10-192259 Japanese Patent Publication No. 50-16919

  In the conventional balance measuring apparatus disclosed in Japanese Patent Application Laid-Open No. 10-192259, the pressure sensor sheet is provided for each small section, so the image becomes a mosaic figure and is not clear. For this reason, it has been difficult to accurately measure the load distribution and the size of the foot. The pressure sensor sheet has a difference in how the load on the measurement table is applied, and a difference occurs in the initial output. Therefore, the amplification factor for the output is different and the measurement accuracy is lacking. Further, since this apparatus is a mechanical mechanism, the mechanism is complicated and expensive, and it causes a failure. In addition, the center of gravity position measuring method disclosed in Japanese Patent Publication No. 50-16919 is provided with a load detector that supports the measuring panel, and since it is a mechanical mechanism such as a load sensor like the former, the center of gravity position detecting mechanism is complicated and expensive. There was also a cause of failure. The pressure / light conversion method for the sole distribution has not yet been able to quickly and easily measure the position of the center of gravity even if the pressure distribution can be observed from the photographed image.

  The present invention pays attention to the contact area of the sole on the glass plate, the amount of incident light, and the variation of the shape that correlates with the foot pressure, and reduces the burden of calculating the center of gravity position quickly by measuring the contact area in the foot contact area image. For the purpose, in the first aspect of the invention, in the method of analyzing the position of the center of gravity from the sole image of the person to be measured, the foot is placed on a transparent plate on which light is projected, and the image pickup means is used to detect the center of gravity from the back side of the transparent plate. Extracting the foot contact portion image data from the captured left and right foot image, the sum of all pixels of the product of the luminance value and coordinate axis of each pixel of the extracted foot contact portion image data, and the foot contact portion The center-of-gravity position of the measurement subject is calculated by dividing by the sum of all luminance values of the image data.

  As a result, the present invention can easily calculate with the ground contact part image data based on the brightness correlated with the sole pressure projected on the glass, so that the position of the center of gravity of the measurement subject can be analyzed quickly and easily with high accuracy. it can.

  According to a second aspect of the present invention, in the method of analyzing the position of the center of gravity from the sole image of the measurement subject, the foot is placed on a transparent plate on which light is projected, and the image is taken from the back side of the transparent plate by the imaging means. The obtained color components of the left and right foot image are converted from RGB values to HSV values, and the foot contact portion image data is extracted with a threshold value. The luminance of each pixel is obtained using the color components of the extracted foot contact portion image data. The center-of-gravity position of the measurement subject is calculated by dividing the sum of all the pixels of the product of the value and the coordinate axis by the sum of all luminance values of the RGB values of the sole ground contact portion image data. The luminance value of each pixel of the present invention is expressed as an RGB value as a digital value, and is the sum of the values.

    In the present invention, the reason why the color component of the foot contact portion image is converted from the RGB value to the HSV value is that the hue can be represented by a 360-degree ring, so that it is easy to distinguish the background color from the human color. Thus, there is an advantage that it is easy to accurately extract the ground contact sole. This is also because the center of gravity position can be calculated easily from the weighted average of RGB values. By this combination, the present invention can accurately extract the foot contact portion image data and analyze the center of gravity position with high accuracy.

  Furthermore, the invention of claim 3 is a method for analyzing the position of the center of gravity from the sole image of the measurement subject, and the image is taken from the back side of the transparent plate by placing the foot on the transparent plate on which light is projected. The obtained color components of the left and right foot image are converted from RGB values to HSV values, the foot contact portion image data is extracted with a threshold value, and the color components of the extracted foot contact portion image data are used for each pixel. Calculate the center of gravity position of the person to be measured by dividing the sum of all the pixels of the product of the brightness value and the coordinate axis and the total brightness of the RGB values of the sole ground contact portion image data, and the left and right footprints of the person to be measured The center of gravity positions of the left and right feet and the entire left and right feet are displayed on the image, respectively.

  As a result, it is possible to visually confirm the position of the center of gravity of the measurement subject and observe the abnormal posture and health of the body.

  According to the center of gravity position analysis method of the present invention, the sole pressure of the foot correlates with the brightness of the ground plane image of the sole image, and all the pixels of the product of the brightness at each pixel of the ground portion of the sole image data and the coordinate axis The center of gravity position can be easily calculated with high accuracy based on the sum of all luminance values of the ground contact portion. In addition, the present invention has an advantage that a conventional pressure (load) sensor is not required and can be easily obtained without failure. In addition, the center of gravity position analysis of the present invention can be performed at high speed because the amount of calculation is small.

  The present invention places a measurement subject's foot on a transparent plate on which light is projected, and uses a coordinate axis and a luminance value in a sole contact image data imaged from the back side of the transparent plate to make high-speed, quick and easy. Realized a method for analyzing the center of gravity.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view showing photographing of the sole of a person to be measured with a camera. FIG. 2 is an explanatory diagram showing the barycentric position of the foot image captured in FIG. 1, and FIG. 3 is a flowchart showing the barycentric position analyzing step.

  As shown in FIG. 1, the person to be measured is placed on a glass plate (transparent plate) in which a screen is formed and a foot F is inserted into the room of the measuring instrument that blocks the external light and the light of the light source 2 is projected inside. The left and right feet are photographed through the reflecting mirror 4 from below the glass plate by the digital camera 3 (imaging means), and a foot image 5 is taken into a computer (not shown) as shown in FIG. The captured footprint image has a blue background, and the left and right soles are captured. At this time, the light projected on the inside of the glass plate is totally reflected in the glass and does not come out, but the skin has a light density higher than that of air. The critical angle becomes large, and light is refracted at the skin contact part and goes out of the glass. The contact area of the skin with the glass increases in proportion to the pressure. Therefore, the light is irregularly reflected on the skin portion, and the amount of light on the contact surface increases in luminance value (light quantity) in proportion to the pressure. If the foot-shaped captured image has image distortion due to the camera installation angle or the lens, it is preferable to obtain a calibration image by correcting the image distortion by a computer.

  Next, the center of gravity position analysis process will be described. First, in step 1, the captured color footprint image 5 is read, and in step 2, RGB values (red, green, blue) are converted into HSV values (hue, saturation, brightness). For example, the RGB value R: 34 G: 116 B: 255 is converted into the HSV value H: 218 S: 87 V: 100. Next, in step 3, the contour of the sole contact portion image 6 is extracted from the footprint image 5 based on the HSV value threshold.

The center-of-gravity position of the person to be measured is obtained as follows using the luminance value (light quantity) of the pixel in the above-mentioned left and right foot sole contact portion image. First, in step 4, the foot contact ground image data of the left and right feet is converted from HSV values to RGB values, and the sum of the RGB values is calculated. Next, in step 5 and step 6, regarding the sole ground contact area, the horizontal coordinate is X, the vertical coordinate is Y, and the luminance value of the pixel at the coordinate (Xm, Yn) is p (Xm, Yn). Calculate the sum of all pixels of the product of the brightness value and the coordinate axis in the X and Y coordinates of the ground coordinates as the brightness moment, and divide the brightness moment by the total brightness value of the RGB values on the ground plane to calculate the left and right foot Find the barycentric coordinates (X _G , Y _G ). The formula to be calculated is as follows.

  Since the center-of-gravity coordinates of the measurement subject determined above are based on the luminance value correlated with the bottom pressure of the foot projected on the glass as described above, it can be regarded as the center of gravity, and can be analyzed with higher accuracy. If the position of the center of gravity 9 is displayed on the foot image 5 in step 7, the center of gravity position of the person to be measured can be visually confirmed to observe the abnormal posture of the body and the health condition.

  According to the present invention, by taking a captured image with a CCD camera and making it a moving image, it is possible to know the situation of the subject's center-of-gravity sway over time, and to obtain data relating to balance ability.

It is explanatory drawing which shows imaging | photography of a to-be-measured person's sole with a camera in one Example of this invention. It is explanatory drawing which shows the gravity center position of the sole image which could be imaged in FIG. In one Example of this invention, it is a flowchart which shows a gravity center position analysis process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass 2 Light source 3 Camera 4 Reflector 5 Foot-shaped image 6 Foot grounding part image 7 Center of gravity position of left foot 8 Center of gravity position of right foot 9 Center of gravity F foot

Claims (3)

  In the method of analyzing the position of the center of gravity from the foot image of the person to be measured, the foot is placed on the transparent plate on which light is projected and the foot is obtained from the left and right foot images obtained by imaging means from the back side of the transparent plate. Extract the back ground image data, and divide by the sum of all pixels of the product of the brightness value of each pixel and the coordinate axis of the extracted foot ground image data and the total brightness value of the foot ground image data. Then, the center-of-gravity position analysis method is characterized in that the center-of-gravity position of the measurement subject is calculated.   In the method of analyzing the position of the center of gravity from the foot image of the person being measured, the colors of the left and right foot images obtained by placing the foot on a transparent plate that has been projected with light and imaging the back surface of the transparent plate by the imaging means The component is converted from the RGB value to the HSV value, the foot contact portion image data is extracted with a threshold value, and all the pixels of the product of the luminance value of each pixel and the coordinate axis are used by using the color component of the extracted foot contact portion image data. The center-of-gravity position analysis method is characterized in that the center-of-gravity position of the person to be measured is calculated by dividing the sum of the above and the total luminance value of the RGB values of the foot contact portion image data.   In the method of analyzing the position of the center of gravity from the sole image of the person to be measured, the foot is placed on the transparent plate on which light is projected, and the left and right foot-shaped images obtained from the back side of the transparent plate by the imaging means The color component is converted from the RGB value to the HSV value, the foot contact portion image data is extracted with the threshold value, and the color component of the extracted foot contact portion image data is used to calculate the product of the luminance value of each pixel and the coordinate axis. The position of the center of gravity of the measurement subject is calculated by dividing the sum of the pixels and the total luminance of the RGB values of the foot ground contact portion image data, and the left and right feet and left and right feet are respectively calculated in the left and right foot images of the measurement subject. Center of gravity position analysis method characterized by displaying the entire center of gravity position.