Pulse detection device and pulse detection method
A frame storage section stores captured images of a predetermined number of frames depicting a region including the skin of a user. A pixel value acquisition section divides the captured images into a plurality of blocks and acquires the pixel values in each block. A pixel exclusion section narrows down target pixels in each block by excluding pixels that have a green value equal to or smaller than a predetermined threshold in a case where pixel colors of each block are represented by RGB. A brightness change compensation section compensates for brightness changes by dividing the average of green values by the average of red or blue values in a case where the colors of the target pixels in each block are represented by RGB. A pulse detection section detects a pulse from temporal changes in target pixel values in each block.
1 . A pulse detection device comprising:
a storage section that stores captured images of a predetermined number of frames depicting a region including skin of a user;
a pixel value acquisition section that divides the captured images into a plurality of blocks and acquires pixel values in each block;
a pixel exclusion section that narrows down target pixels in each block by excluding pixels that have a green value equal to or smaller than a first predetermined threshold and pixels that have a red value equal to or greater than a second predetermined threshold in a case where pixel colors of each block are represented by RGB, wherein the second predetermined threshold is greater than the first predetermined threshold; and
a pulse detection section that detects a pulse from temporal changes in target pixel values in each block.
2 . The pulse detection device according to claim 1 , wherein, when the pixel colors of each block are represented by a hue, the pixel exclusion section narrows down the target pixels in each block by further excluding pixels having a hue within a predetermined range.
3 . The pulse detection device according to claim 1 , further comprising:
a brightness change compensation section that compensates for brightness changes by dividing an average of green values by an average of red or blue values in a case where the colors of the target pixels in each block are represented by RGB, wherein the pulse detection section detects a pulse from temporal changes in the pixel values in each block after brightness change compensation.
4 . The pulse detection device according to claim 3 , wherein the brightness change compensation section compensates for brightness changes by dividing the average of green values by a sum of the average of red values and the average of blue values in the case where the pixel colors of each block are represented by RGB.
5 . A pulse detection device comprising:
a storage section that stores captured images of a predetermined number of frames depicting a region including skin of a user;
a pixel value acquisition section that divides the captured images into a plurality of blocks and acquires pixel values in each block;
a brightness change compensation section that compensates for brightness changes by dividing an average of green values by a sum of an average of red values and an average of blue values in a case where the pixel colors of each block are represented by RGB; and
a pulse detection section that detects a pulse from temporal changes in the pixel values in each block after brightness change compensation.
6 . A pulse detection method comprising:
dividing captured images of a predetermined number of frames depicting a region including skin of a user into a plurality of blocks and acquiring pixel values in each block;
narrowing down target pixels in each block by excluding pixels that have a green value equal to or smaller than a first predetermined threshold and pixels that have a red value equal to or greater than a second predetermined threshold in a case where pixel colors of each block are represented by RGB, wherein the second predetermined threshold is greater than the first predetermined threshold; and
detecting a pulse from temporal changes in target pixel values in each block.
7 . A non-transitory, computer-readable storage medium containing a computer program, which when executed by a computer, causes the computer to implement a pulse detection method by carrying out actions, comprising:
dividing captured images of a predetermined number of frames depicting a region including skin of a user into a plurality of blocks and acquiring pixel values in each block;
narrowing down target pixels in each block by excluding pixels that have a green value equal to or smaller than a first predetermined threshold and pixels that have a red value equal to or greater than a second predetermined threshold in a case where pixel colors of each block are represented by RGB, wherein the second predetermined threshold is greater than the first predetermined threshold; and
detecting a pulse from temporal changes in target pixel values in each block.
8 . The pulse detection device of claim 1 , further comprising:
a time-series pixel array acquisition section configured to acquire a time-series pixel array comprising the pixel values in each block.
9 . The pulse detection device of claim 8 , wherein the time-series pixel array acquisition section is configured to perform low-pass filtering on the time-series pixel array to acquire a temporarily smoothed time-series pixel array.
10 . The pulse detection device of claim 8 , further comprising:
a pulse data array acquisition section configured to perform high-pass filtering (HPF) on the time-series pixel array.
11 . The pulse detection method of claim 6 , further comprising:
wherein, when the pixel colors of each block are represented by a hue, narrowing down the target pixels in each block by further excluding pixels having a hue within a predetermined range.
12 . The pulse detection method of claim 6 , further comprising:
compensating for brightness changes by dividing an average of green values by an average of red or blue values in a case where the colors of the target pixels in each block are represented by RGB; and
detecting a pulse from temporal changes in the pixel values in each block after brightness change compensation.
13 . The pulse detection method of claim 12 , further comprising:
compensating for brightness changes by dividing the average of green values by a sum of the average of red values and the average of blue values in the case where the pixel colors of each block are represented by RGB.
14 . The pulse detection method of claim 6 , further comprising:
acquiring a time-series pixel array comprising the pixel values in each block.
15 . The pulse detection method of claim 14 , further comprising:
performing low-pass filtering on the time-series pixel array to acquire a temporarily smoothed time-series pixel array.
16 . The pulse detection method of claim 14 , further comprising:
performing high-pass filtering (HPF) on the time-series pixel array.
17 . The non-transitory, computer-readable storage medium of claim 7 , wherein the actions further comprise:
when the pixel colors of each block are represented by a hue, narrowing down the target pixels in each block by further excluding pixels having a hue within a predetermined range.
18 . The non-transitory, computer-readable storage medium of claim 7 , wherein the actions further comprise:
compensating for brightness changes by dividing an average of green values by an average of red or blue values in a case where the colors of the target pixels in each block are represented by RGB; and
detecting a pulse from temporal changes in the pixel values in each block after brightness change compensation.
19 . The non-transitory, computer-readable storage medium of claim 18 , wherein compensating for the brightness changes comprises dividing the average of green values by a sum of the average of red values and the average of blue values in the case where the pixel colors of each block are represented by RGB.
20 . The non-transitory, computer-readable storage medium of claim 7 , wherein the actions further comprise:
acquiring a time-series pixel array comprising the pixel values in each block.