Iris locating method based on radial gradient detection

A radial gradient and iris positioning technology, which is applied in image data processing, instruments, character and pattern recognition, etc., can solve the problems of inability to accurately locate the iris, slow iris positioning speed, etc.

Active Publication Date: 2015-01-07
BEIJING INST OF RADIO METROLOGY & MEASUREMENT
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  • Claims
  • Application Information

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Problems solved by technology

[0009] The purpose of the present invention is to provide an iris positioning method based on radial gradient detection, which solves the problems of slow iris positioning speed and inability to accurately locate iris due to local interference

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  • Iris locating method based on radial gradient detection
  • Iris locating method based on radial gradient detection
  • Iris locating method based on radial gradient detection

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Embodiment Construction

[0076] In order to explain the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and drawings. Similar components in the drawings are denoted by the same reference numerals. Those skilled in the art should understand that the content described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

[0077] The specific steps of an iris location method based on radial gradient detection are:

[0078] The first step is to obtain an iris image, estimate the position of the pupil center and use it as a reference point to divide the iris area to be searched.

[0079] First, search for the location where the image point of the light source may exist. In practice, the collected iris image has different degrees of interference. In order to eliminate the influence of high-frequency interference on the iris boundary positioning, the iris image is smoothed:...

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Abstract

The invention discloses an iris locating method based on radial gradient detection. The method comprises the steps of estimating the position of the center of a pupil, dividing an iris area to be searched for with the position as the reference point, and spreading the iris area to be searched for into a rectangular area with a specific size according to polar coordinates; locating the inner boundary of the iris area through the radial gradient detection method; locating the outer boundary of the iris area through the radial gradient detection method, and carrying out fine adjustment on the reference radius of the outer boundary according to the radial gradient in a neighborhood. According to the technical scheme, it is not needed to carry out pointwise three-dimensional space search on the iris boundaries within a large range or carry out self-adaptation determination on an edge detection and area segmentation complexity threshold value, disturbing influence caused by light source image points and uneven illumination is small, rapid and accurate iris locating can be achieved, and therefore the recognition speed of an iris recognition system can be increased, and the recognition accuracy of the iris recognition system can be improved.

Description

Technical field [0001] The invention relates to an image segmentation method. More specifically, it relates to a fast iris positioning method for an iris biometric system. Background technique [0002] Iris recognition has gradually become a research hotspot and development trend in the field of biometrics with its significant advantages such as accuracy, stability, safety and non-contact. In the iris recognition system, iris image preprocessing (including iris location, interference detection, normalization and image enhancement, etc.) is the premise of iris recognition, and iris location is the key. Only when the positioning is accurate, more effective iris features can be extracted to realize accurate recognition. However, in practical applications, due to the hardware limitations of the acquisition equipment and the lighting changes in the acquisition environment, the acquired iris images often have varying degrees of noise interference, blurred details, and low contrast, w...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06K9/00G06K9/32G06T7/00
CPCG06T7/11G06T2207/30196G06V40/193G06V10/245
Inventor 郭慧杰王超楠杨倩倩韩一梁杨昆年丰
Owner BEIJING INST OF RADIO METROLOGY & MEASUREMENT
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