Authentication object image-pickup method and device therefor
First Claim
1. An authentication object image pickup method comprising:
- allowing an image signal obtained by picking up an authentication object to pass through a filter;
searching a lens position in which an output of the filter indicates a peak value by a mountaineering method;
searching a peak position of a high frequency component in the image signal obtained by searching for a whole area within a predetermined range;
capturing an image focused on the authentication object;
determining whether an amount of a high luminance component included in the image signal is equal to or greater than a predetermined value;
switching between the searching process of the peak position of the high frequency component and the searching process by the mountaineering method based on a result of the determining process; and
setting the peak position or a focusing position corresponding to the lens position to an authentication object focusing position.
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Accused Products
Abstract
In an iris image pickup method in which an image signal picking up an iris is allowed to pass through a high-pass filter (41L) and a lens position in which an output of the high-pass filter (41L) indicates a peak value is searched by a mountaineering method, thereby capturing an iris image focused on the iris, when an amount of a high luminance component included in the image signal is equal to or greater than a predetermined value, a peak position of a high frequency component in the image signal passing through a narrow-band high-pass filter (41H) for causing only a high band in a pass band of the high-pass filter (41L) to pass therethrough is obtained by searching for a whole area within a predetermined range in place of a search for a focusing position by the mountaineering method, and is set to be an iris focusing position. Consequently, it is possible to acquire a clear iris image having a high authentication rate which is focused on the iris in place of glasses. Also in the case in which an authentication object person wears the glasses, consequently, an image focused on the iris can be acquired.
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Citations
14 Claims
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1. An authentication object image pickup method comprising:
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allowing an image signal obtained by picking up an authentication object to pass through a filter; searching a lens position in which an output of the filter indicates a peak value by a mountaineering method; searching a peak position of a high frequency component in the image signal obtained by searching for a whole area within a predetermined range; capturing an image focused on the authentication object; determining whether an amount of a high luminance component included in the image signal is equal to or greater than a predetermined value; switching between the searching process of the peak position of the high frequency component and the searching process by the mountaineering method based on a result of the determining process; and setting the peak position or a focusing position corresponding to the lens position to an authentication object focusing position. - View Dependent Claims (2, 3, 4, 5, 6, 13)
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7. An authentication object image pickup apparatus comprising:
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image pickup means for picking up an image of an authentication object; a filter for allowing an image signal captured by the image pickup means to pass therethrough; control means for allowing the image pickup means to capture an image focused on the authentication object; means for searching for a lens position in which an output of the filter indicates a peak value by a mountaineering method; means for searching for a whole area within a predetermined range to obtain a peak position of a high frequency component in the image signal; determining means for determining whether an amount of a high luminance component included in the image signal is equal to or greater than a predetermined value; switching means for switching between the searching process of the peak position of the high frequency component and the searching process by the mountaineering method based on a result of the determining process; and setting means for setting the peak position or a focusing position corresponding to the lens position to an authentication object focusing position. - View Dependent Claims (8, 9, 10, 11, 12, 14)
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Specification