JP5162764B2 - Automatic determination method of foot measurement reference line in foot measurement - Google Patents

Description

  The present invention relates to a method for automatically determining a foot-shaped measurement reference line in foot-shaped measurement for measuring the dimensions of a foot.

In the case of measuring a foot shape necessary for shoe manufacture or shoe selection, conventionally, as seen in Reference 1, Reference 2, Reference 3, and Reference 4, an outline projection line of a foot image captured by a camera or a scanner is used. A method of printing, drawing a foot-shaped measurement reference line, and manually measuring the foot length, foot width, and other values based on the foot-shaped measurement reference line using a scale, a ruler, or the like was employed. Alternatively, as can be seen in Document 5, in the foot image displayed on the computer screen of the foot-type measuring instrument, the foot-type measurement reference line (the saddle point and the second point) is used by using a computer mouse or other pointer operation device. A line connecting the cusps) was drawn visually, and the foot length, foot width, and other values were measured based on this.
JP 2001-207 (JP, A) JP 2000-296005 (JP, A) Japanese Patent Laid-Open No. 11-10023 (JP, A) JP-A-8-166219 JP-A-2004-219404

  In the case of length measurement based on hand-drawn reference lines as in Reference 1, Reference 2, Reference 3, and Reference 4, or visual foot-shaped measurement reference lines as in Reference 5, eye measurement errors or individual differences In some cases, a measurement error may occur.

  When performing automatic drawing of the foot-shaped measurement reference line, the automatic determination method of the apex point is to draw a tangent to the contour projection line, and the boundary point where the gradient changes from positive to negative or from negative to positive (inflection) Point) or a method of using a minimum value or maximum value from the reference to the outline projection line as a cusp in the video camera as a reference. . In these methods, when the contour line of the image changes monotonously and the value near the inflection point suddenly increases or decreases, the cusp can be determined stably. However, if the curvature of the contour line is gradual, or if the curvature changes slightly due to noise mixed in the video image, it may not be possible to automatically determine a highly accurate foot type measurement reference line. Practical application has been difficult.

  In order to eliminate such inconvenience, the present invention can automatically determine the foot-shaped measurement reference line by a computer program, thereby eliminating an operation error of the measurer, It aims at providing the foot type measuring instrument which can reduce a burden.

  In order to achieve such an object, the present invention comprises means for imaging the foot on the footrest transparent plate from the back side of the footrest transparent plate, and can automatically measure the foot shape from the image information obtained by the imaging means. It is characterized by.

  As shown in FIG. 1, the foot shape is a line connecting the rear most apex point (referred to as a saddle point) 1 of the heel portion and the second cusp point 2 (this line is referred to as a foot shape measurement reference line) 3. , The intersection 6 between the perpendicular 5 from the cusp 4 of the other buttocks (the first heel in the example in FIG. 1) and the foot measurement reference line 3 to the foot measurement reference line is the second cusp 2 If it is in the heel direction, the length between the heel point 1 and the second cusp point 2 is the foot length value. As shown in FIG. 2, in the foot-shaped measurement reference line 3, the perpendicular 5 from the cusp 4 of the heel other than the second heel (first heel in the example of FIG. 2) to the foot-shaped measurement reference line 3 and the foot shape. When the length between the intersection 6 with the measurement reference line 3 and the saddle point 1 is longer than the length between the saddle point 1 and the second cusp point 2, the saddle point 1 on the foot-shaped measurement reference line 3 and The length between the point 6 of the heel other than the second heel and the intersection 6 with the perpendicular 5 drawn down to the foot-shaped measurement reference line 3 is defined as a foot length value.

The automatic determination method of the foot-shaped measurement reference line 3 is as follows. In FIG. 3, the scanning of the video camera starts from the upper left. As shown in FIG. 3, it is assumed that the left foot image 7 is photographed in the upper half of the screen, the right foot image 8 is photographed in the lower half, and the heel portion is on the start side 9 of the horizontal scanning. In the video signal thus captured, the number of pixels up to the buttock outline projection line 10 (the number of ridge outline projection line position pixels) is obtained with reference to the horizontal scanning start time 9 of the video signal. This minimum value position is assumed to be a temporary saddle point 11 (X ₁₁ , Y ₁₁ ). The number of pixels from the temporary saddle point 11 to the contour projection line 12 in the claw tip direction (the number of pixels between the saddle point and the contour projection line) is calculated.

This calculation method is as follows. In FIG. 4, an intersection 16 of a straight line 13 in the horizontal scanning line direction from the temporary saddle point 11 and a perpendicular line 15 dropped from the one point 14 (X ₁₄ , Y ₁₄ ) on the claw toe outline projection 12 to the straight line 13. (X ₁₆ , Y ₁₆ ) is obtained. A length L (heel-toe) from the temporary saddle point 11 (X ₁₁ , Y ₁₁ ) to the buttocks outline projection line can be calculated by the following equation.
L (heel-toe) = root ((X ₁₆ −X ₁₁ ) ² + (Y ₁₆ −Y ₁₄ ) ² )
FIG. 5 shows the buttock outline projection line pattern drawn by this L (heel-toe) value. As a result of the preliminary examination, in most cases, the shape of the heel was preserved up to the first heel part 17, the second heel part 18, and the third heel part 19. Using this, the change in the L (heel-toe) value from the first heel side is examined, and after obtaining the local maximum value of L (heel-toe) related to the first heel, the shift proceeds to a decrease. The maximal value position of L (heel-toe) is set as a temporary second cusp point 20 (FIG. 3). As shown in FIG. 6, the point of the buttocks outline projection line having the maximum length to the buttocks outline projection line is analyzed starting from the temporary second cusp point 20. This part is defined as a true saddle point 1. In FIG. 7, the second saddle outline projection line 21 having the longest distance from the true saddle point 1 to the intersection of the second saddle outline projection line 21 starting from the true saddle point 1. Let the upper point be the true second cusp point 2. A line connecting the true saddle point 1 and the true second cusp point 2 obtained in this way is defined as a foot-shaped measurement reference line 3. The foot length, foot width, and foot circumference are obtained by the same method as disclosed in JP-A-2004-219404.

  The foot type measurement reference line of the right foot is determined as shown in FIG. Assume that the right foot image is captured in the latter half of the imaging surface of the video camera, as shown in FIG. Similar to the left foot measurement, the minimum pixel number position from the horizontal scanning start point to the buttocks outline projection line is first detected in the image signal for the second half of the screen of the video camera. This point is a temporary saddle point. The number of pixels from the temporary saddle point to the foot outline projection line in the tip direction is measured. Based on this value, a temporary second cusp point is detected. The position of the maximum number of pixels from the temporary second cusp point to the buttock contour projection line of the heel method is detected. This is the true saddle point. Using this true saddle point as a starting point, the position of the maximum number of pixels (true second saddle point) up to the outline projection line of the second collar is detected. A line connecting the true saddle point and the true second cusp point is set as a foot-shaped measurement reference line of the right foot. The foot length, foot width, and other analyzes are the same as the left foot measurement method.

  In the case where the eyelid is projected on the scanning start side of the video camera, and the eyelid is projected on the opposite side, the eyelid contour projection that minimizes the number of pixels to the eyelid contour projection line with reference to the end point of the horizontal scanning The points on the line are set as temporary saddle points, and others can be obtained by the same method as the left foot measurement.

  Conversion of the foot shape value to the actual size value with the number of pixels obtained from the image as a unit is possible by the following method. Place a ruler of a known size on the base for acquiring the image of the sole, find the number of pixels of the ruler image, create a conversion formula from the number of pixels to the actual size, and calculate the number of pixels of the image from the conversion formula Can be converted to actual size.

  According to a preliminary experiment, the accuracy of the measurement of the foot shape by this method was within an error of 1 mm in 97 cases out of 100 cases based on hand measurement values.

  According to the present invention, a foot-shaped measurement reference line can be automatically drawn, and measurement errors can be prevented. As a result, a person other than a measurement expert can perform accurate measurement. Further, it is possible to reduce the labor of drawing by visual observation so far, and efficient measurement is possible.

  One embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a schematic side view of an example of a plantar image acquisition device, and FIG. 10 is a top view (excluding a light shielding screen). As shown in FIG. 9, this apparatus has a glass plate 22 for placing a foot on a person to be measured, an illuminating device 23 for taking an image, a mirror 24, an image acquisition device (video camera) 25, and fixing these to external light. It comprises a shielding box 26, a light blocking sheet 27 from above, a data processing computer 28, and a printer 29 for outputting processing results. FIG. 11 is an example of an image acquired in this apparatus example. The processing shown in FIGS. 1 to 10 is performed on the contour projection line of the sole image of the video image. FIG. 12 is an example showing a processing result.

  FIG. 13 shows an example of a procedure when image processing is performed by a computer. In the video shooting apparatus, as shown in FIG. 3, the left foot is ½ of the screen from the beginning of the vertical scanning, the right foot is on the other half of the screen, and the buttock direction is directed to the starting side of the horizontal scanning. It shall be taken. First, the plantar image from the sole direction is captured from the camera into the computer using the apparatus of FIG. 9 (step-2). The image signal is processed to extract an outline projection line (contour line) of the foot image (step-3). With respect to the outline projection line, the number of pixels from the start of horizontal scanning of the video signal to the outline projection line is measured (step-4). This is repeated up to 1/2 in the vertical scanning direction (1/2 portion of the screen) (step-5). The position of the buttocks (temporary saddle point) of the minimum number of pixels in this measurement is determined (step-6). Next, the length between the temporary saddle point and the contour projection line in the footpad direction is measured (step-7). This is repeated up to 1/2 of the vertical operation direction (1/2 part of the screen) (step-8). The position of the intersection of the line indicating the maximum value of the values of the second collar and the second collar outline projection line is set as a temporary second cusp (step-9). A point on the buttock outline projection line having the maximum distance from the provisional second cusp point to the buttock outline projection line is obtained. This point position is set as a true saddle point (step-10, step-11, step-12). A point (true second cusp point) on the outline projection line of the second buttock that gives the maximum distance from the true ridge point to the outline projection line of the second buttock (step-13, step) -14, step-15). A line connecting the true saddle point and the true second cusp point is set as a foot measurement reference line (step-16). A length L (heel-tx) between the perpendicular from the cusp other than the second heel to the foot measurement reference line and the intersection of the foot measurement reference line and the true heel point is true second. If it is longer than the length L (heel-ts) between the cusps, L (heel-tx) is set as the foot length value (step-18, step-19). When the length L (heel-ts) between the true saddle point and the true second cusp point is longer than (heel-tx), L (heel-ts) is set as the foot length value (step- 20). The right foot is also calculated in the same way (step 21, step-22).

  The present invention enables the automatic measurement required by the industry for the measurement of the foot type, and can be easily incorporated into the conventional measuring instrument. With the availability of

  It is explanatory drawing of the foot type | mold measurement method 1.   It is explanatory drawing of the foot type | mold measurement method 2nd.   It is explanatory drawing of the imaging | photography condition of a sole, a provisional saddle point, and the detection method of a provisional 2nd cusp point.   It is explanatory drawing of the calculation method of length.   It is explanatory drawing of the recognition method of a 2nd collar.   It is explanatory drawing of the most apex position (saddle point) analysis method of a buttocks.   It is explanatory drawing of the analysis method of a true 2nd cusp.   It is explanatory drawing of the foot type measuring method of a right leg.   It is an upper surface schematic diagram of the example of a device for foot sole part image acquisition.   It is a top view of the example of a device for foot sole part image acquisition.   It is the example of an image acquired in the plantar part image acquisition apparatus.   It is an outline projection line figure obtained by processing of a sole part image.   It is the figure (flowchart) which showed the example of the procedure of the process in a computer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Acupuncture point 2 2nd caudal point 3 Foot-shaped measurement reference line 4 Vertical line from 1st cusp point to foot-shaped measurement reference line 5 First cusp point 6 Foot shape from 1st cusp point Intersection of perpendicular line to measurement reference line and foot-shaped measurement reference line 7 Right foot image position 8 Left foot image position 9 Horizontal scanning start part 10 in video signal groin outline projection line 11 temporary saddle point 12 heel toe direction outline projection line 13 Auxiliary horizontal line 14 for measuring the length of the diagonal line A point 15 on the second buttock contour projection line 15 A perpendicular line 16 from a point on the second buttock outline projection line to the auxiliary horizontal line for measuring the diagonal line length The diagonal line length The intersection 17 of the measurement auxiliary horizontal line 13 and the perpendicular 15 from the point 14 on the second buttock outline projection line The first ridge outline projection line 18 drawn based on the measurement value The second ridge part drawn based on the measurement value Outline projection line 19 Third ridge outline projection line 20 drawn based on the measured value Temporary second cusp 21 second toes outer projection line 22 glass plate 23 illumination source (fluorescent lamp)
24 Reflector 25 Video (digital) camera 26 Glass / mirror / camera support / light-shielding box 27 Light-shielding sheet 28 Calculation computer 29 Printer 30 Subject's foot

Claims (1)

  In digital image processing, a point near the most protruding point behind the heel on the foot outline projection line is set as a temporary heel point, and the distance from the temporary heel point to the outline projection line of the second heel area is set as a base point. The point on the second buttocks outline projection line that becomes the maximum is the temporary second cusp point, and the length of the heel part that has the maximum length from the provisional second cusp point to the outline projection line of the buttock is the maximum. A point on the outline projection line is set as a true saddle point, and a point on the second outline projection line having the maximum length between the true saddle point and the second outline of the outline projection line is set as the true first point. A method for determining a foot-shaped measurement reference line in foot-shaped measurement in which a two-point cusp point is used and a line passing through a true heel point and a true second cusp point is a foot-shaped measurement reference line.

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