The brightness characteristic quantity extracting method of characteristic image and the recognition methods of characteristic image
Technical field
The present invention relates to a kind of Characteristic Extraction method of characteristic image, especially relate to a kind of brightness characteristic quantity extracting method of face image.
Background technology
In recent years, a kind of characteristic pattern that utilizes camera picked-up has been proposed, face for example, the practical approach of identification people's identity.A kind of matching process commonly used is, handle by for example between predefined registered images and processing target image, carrying out identifications such as standardization correlativity, calculate similarity, and finally judge that according to similarity whether people to be identified is the people of registered in advance in recognition system.
When (for example security system) provides the recognition of face of using this matching process under real-time environment, exist following may: because weather or the variation in division of day and night in a day, the contrast of image changes can be very greatly, even can produce local shade in image.In real time environment, the appearance of the people in the image can be according to the variation that is changed significantly of light, and this will greatly influence accuracy of identification.
In order to address this problem, the someone proposed will with respect to the variation of light more the stable characteristics amount from brightness value, extract, rather than originally carry out identification on one's body at the brightness value of image and handle.For example, with the brightness value of each pixel of each comparison in position by and the difference around between the pixel of this pixel revise, then the brightness value of revising is defined as the final brightness value of this pixel.
Yet prior art exists correcting mode rough, and final brightness value is accurate inadequately, and revises the shortcoming that efficient is too low at each pixel.
Summary of the invention
For solving the problems of the technologies described above, according to a scheme of the present invention, the invention provides a kind of brightness characteristic quantity extracting method of face image, it utilizes the face image recognition system to carry out brightness characteristic quantity and extracts, described face image recognition system comprises: image storage unit, adjustment cut cells, sign unit, brightness characteristic quantity extraction unit, storage unit
The brightness characteristic quantity extracting method of described face image may further comprise the steps:
Input step is input to face image to be registered or face image to be identified in the described image storage unit of described face image recognition system by camera;
Set-up procedure, with the face image stored by the adjustment of described adjustment cut cells and be cut into the standard face image of direction, the certain standard of size conforms;
The position indicates step, and described standard face image is cut apart sign by described sign unit according to the position;
Extraction step extracts the brightness characteristic quantity of each station diagram picture with described brightness characteristic quantity extraction unit to each the station diagram picture that is indicated;
Storing step is stored in described brightness characteristic quantity in the described storage unit;
Wherein, described extraction step comprises:
Identification step is discerned the brightness value of each pixel in each station diagram picture;
First comparison step, a pixel in the extract part image is as object pixel, all pixels institute that will be adjacent with this object pixel as object pixel around pixel, calculate each object pixel around the luminance difference between pixel and the object pixel, if described luminance difference be no more than described object pixel brightness ± 20%, then should be classified as an object pixel group around pixel and described object pixel;
Second comparison step, all pixels that will be adjacent with the described object pixel group that obtains in described first comparison step as pixel groups around pixel, calculate each pixel groups around the luminance difference between pixel and the described object pixel that in described first comparison step, extracts, if described luminance difference be no more than described object pixel brightness+100%, be+1 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness+100%, be+2 around pixel counts then with this pixel groups; If described luminance difference be no more than described object pixel brightness-50%, be 0 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness-50%, be-1 around pixel counts then with this pixel groups;
Calculation procedure, described each pixel groups added up around the counting of pixel obtains a final brightness value, and this final brightness value is distributed to each object pixel in the described object pixel group, obtains the brightness characteristic quantity of each object pixel thus;
Determining step, order is extracted the one other pixel outside the object pixel group, as object pixel, repeats first comparison step, second comparison step and calculation procedure, and all pixels in the station diagram picture all obtain the brightness value.
Further, in the brightness characteristic quantity extracting method of face image of the present invention, described image storage unit comprises the face image storing sub-units of registration and face image storing sub-units to be identified.
Further, in the brightness characteristic quantity extracting method of face image of the present invention, input step is input to face image to be registered or face image to be identified in the face image storing sub-units of the described registration in the described image storage unit of described face image recognition system by camera;
Further, in the brightness characteristic quantity extracting method of face image of the present invention, indicate in the step, described standard face image is cut apart sign according to the position with digital mode by described sign unit at described position.
Further, in the brightness characteristic quantity extracting method of face image of the present invention, indicate step at described position, described standard face image is cut apart sign by described sign unit according to the position, and described position comprises face, eyebrow, eyes, nose, chin and the cheekbone of face.
Further, in the brightness characteristic quantity extracting method of characteristic image of the present invention, in described calculation procedure, described each pixel groups added up around the counting of pixel obtain a final brightness value, this final brightness value is distributed to each object pixel in the described object pixel group, and, if described final brightness value be not more than+2 or be not less than-2, then described final brightness value is set at 0, obtains the brightness characteristic quantity of each object pixel thus.
According to another aspect of the present invention, the invention provides a kind of recognition methods of characteristic image, may further comprise the steps:
Registration image input step is input to characteristic image to be registered in the described image storage unit of described characteristic image recognition system by camera;
Set-up procedure, with the characteristic image stored by the adjustment of described adjustment cut cells and be cut into the standard feature image of direction, the certain standard of size conforms;
The position indicates step, and described standard feature image is cut apart sign by described sign unit according to the position;
Extraction step extracts the brightness characteristic quantity of each station diagram picture with described brightness characteristic quantity extraction unit to each the station diagram picture that is indicated;
Storing step is stored in described brightness characteristic quantity in the described storage unit;
Wherein, described extraction step comprises:
Identification step is discerned the brightness value of each pixel in each station diagram picture;
First comparison step, a pixel in the extract part image is as object pixel, all pixels institute that will be adjacent with this object pixel as object pixel around pixel, calculate each object pixel around the luminance difference between pixel and the object pixel, if described luminance difference be no more than described object pixel brightness ± 20%, then should be classified as an object pixel group around pixel and described object pixel;
Second comparison step, all pixels that will be adjacent with the described object pixel group that obtains in described first comparison step as pixel groups around pixel, calculate each pixel groups around the luminance difference between pixel and the described object pixel that in described first comparison step, extracts, if described luminance difference be no more than described object pixel brightness+100%, be+1 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness+100%, be+2 around pixel counts then with this pixel groups; If described luminance difference be no more than described object pixel brightness-50%, be 0 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness-50%, be-1 around pixel counts then with this pixel groups;
Calculation procedure, described each pixel groups added up around the counting of pixel obtains a final brightness value, and this final brightness value is distributed to each object pixel in the described object pixel group, obtains the brightness characteristic quantity of each object pixel thus;
Determining step, order is extracted the one other pixel outside the object pixel group, as object pixel, repeats first comparison step, second comparison step and calculation procedure, and all pixels in the station diagram picture all obtain the brightness value;
Image input step to be identified is input to characteristic image to be identified in the described image storage unit of described characteristic image recognition system by camera;
Repeat above-mentioned set-up procedure, position sign step, extraction step and storing step, thereby obtain the brightness characteristic quantity of characteristic image to be identified;
The characteristic portion of choosing according to the user more than three or from image storage unit, extract the brightness characteristic quantity of characteristic image to be identified at described position respectively according to a plurality of positions that described image identification system is set and the brightness characteristic quantity of the characteristic image of registration;
The brightness characteristic quantity of the characteristic image of the brightness characteristic quantity of the characteristic image described to be identified that extracted and described registration is compared,, then be judged to be characteristic image to be identified by identification if both are similar; Both are not similar else if, then are judged to be characteristic image to be identified not by identification.
Further, in the recognition methods of characteristic image of the present invention, comprise at least in the characteristic portion more than three that described user chooses face face, eyebrow, eyes, nose, chin and cheekbone one of them.
Further, in the brightness characteristic quantity extracting method of characteristic image of the present invention, in described calculation procedure, described each pixel groups added up around the counting of pixel obtain a final brightness value, this final brightness value is distributed to each object pixel in the described object pixel group, and, if described final brightness value be not more than+2 or be not less than-2, then described final brightness value is set at 0, obtains the brightness characteristic quantity of each object pixel thus.
Further, the brightness characteristic quantity extracting method of characteristic image as claimed in claim 7, wherein, in described first comparison step, if described luminance difference be no more than described object pixel brightness ± 10% o'clock, then should be classified as an object pixel group around pixel and described object pixel.
By technical scheme provided by the present invention, recognition system can be classified as one group with the similar pixel of brightness, thereby has improved efficient.And according to luminance difference, be more meticulously, thereby more accurately determine the final brightness value of object pixel, thereby obtain the brightness characteristic quantity of each object pixel around pixel setup parameter value around pixel and object pixel.
Embodiment
To describe the present invention in detail by embodiment below:
Utilized the characteristic image recognition system in the brightness characteristic quantity extracting method of characteristic image provided by the invention.The feature identification system can be by comparing to the feature feature of having stored and feature feature to be tested, and determine that whether people to be identified is some among the personnel that registered.Described characteristic image recognition system comprises: image storage unit, adjustment cut cells, sign unit, brightness characteristic quantity extraction unit, storage unit.The effect of these unit is as described below.
Yet the characteristic image of obtaining by camera can be because of the colour of skin and because of the variation of extraneous light produces luminance difference, and this species diversity may cause the failure discerned.Therefore need the special brightness of paying attention to characteristic image, therefore need provide a kind of maximum possible to get rid of the brightness characteristic quantity extracting method of the characteristic image of light variable effect.
The brightness characteristic quantity extracting method of characteristic image provided by the invention may further comprise the steps:
Input step is input to characteristic image to be registered or characteristic image to be identified in the described image storage unit of described characteristic image recognition system by camera.Because this method both had been suitable for the characteristic image of the registration of typing is in advance handled, be fit to the characteristic image that corresponding time spent needs discern again and handle, therefore in described input step, input can be in two kinds of images any.
Set-up procedure, with the characteristic image stored by the adjustment of described adjustment cut cells and be cut into the standard feature image of direction, the certain standard of size conforms.Adjust cut cells the processing target image of input is carried out detection, and position, the size and Orientation of the feature in definite processing target image.In addition, adjust cut cells based on the extremely predetermined size of determined feature locations, characteristic dimension and characteristic direction standardization face size; Produce the test pattern of shearing by shearing characteristic image, like this, characteristic portion is along predetermined direction orientation; And the standard picture sheared of output.
The position indicates step, and described standard feature image is cut apart sign by described sign unit according to the position.Can indicate with numeral when indicating, also can indicate with letter.Sign is when discerning in the future, can be exactly selects identical position on the characteristic image of registration and other characteristic image to be known.
Extraction step extracts the brightness characteristic quantity of each station diagram picture with described brightness characteristic quantity extraction unit to each the station diagram picture that is indicated;
Wherein, described extraction step comprises:
Identification step is discerned the brightness value of each pixel in each station diagram picture.
First comparison step, a pixel in the extract part image is as object pixel, all pixels institute that will be adjacent with this object pixel as object pixel around pixel, calculate each object pixel around the luminance difference between pixel and the object pixel, if described luminance difference be no more than described object pixel brightness ± 20%, then should be classified as an object pixel group around pixel and described object pixel.For example the brightness value of Xuan Ding object pixel is 100, then can be classified as one group around brightness value in the pixel with described object pixel between 80~120, becomes an object pixel group.Suppose there are eight around pixel around the object pixel, and wherein two brightness values around pixel are formed the object pixel groups that comprise three pixels around pixel and that object pixel for these two so between 80~120.
Second comparison step, all pixels that will be adjacent with the described object pixel group that obtains in described first comparison step as pixel groups around pixel, calculate each pixel groups around the luminance difference between pixel and the described object pixel that in described first comparison step, extracts, if described luminance difference be no more than described object pixel brightness+100%, be+1 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness+100%, be+2 around pixel counts then with this pixel groups; If described luminance difference be no more than described object pixel brightness-50%, be 0 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness-50%, be-1 around pixel counts then with this pixel groups.For example, with the top object pixel group adjacent pixels that comprises three pixels, just and in described three pixels any one adjacent pixels as pixel groups around pixel.Yet around the pixel setup parameter, if the described luminance difference of parameter setting rule is no more than brightness+100% of described object pixel, is+1 with this pixel groups around pixel counts to each; If described luminance difference surpass described object pixel brightness+100%, be+2 around pixel counts then with this pixel groups; If described luminance difference be no more than described object pixel brightness-50%, be 0 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness-50%, be-1 around pixel counts then with this pixel groups.This rule can make around the luminance parameter of pixel more accurate, thereby makes that the follow-up setting to the object pixel luminance parameter is more accurate.
Calculation procedure, described each pixel groups added up around the counting of pixel obtains a final brightness value, and this final brightness value is distributed to each object pixel in the described object pixel group, obtains the brightness characteristic quantity of each object pixel thus.That is to say that the brightness value (brightness characteristic quantity) of each object pixel in object pixel group is the same.Thereby simplified computation process, recognition efficiency is provided.
Determining step, order is extracted the one other pixel outside the object pixel group, as object pixel, repeats first comparison step, second comparison step and calculation procedure, and all pixels in the station diagram picture all obtain the brightness value.This position pixel has just obtained brightness characteristic quantity like this.
Be storing step at last, described brightness characteristic quantity is stored in the described storage unit.
In the brightness characteristic quantity extracting method of described characteristic image, described image storage unit comprises the characteristic image storing sub-units of registration and characteristic image storing sub-units to be identified.Like this can be with characteristic image to be registered and characteristic image separate storage to be identified.
In the brightness characteristic quantity extracting method of described characteristic image, in described input step, characteristic image to be registered or characteristic image to be identified are input to by camera in the characteristic image storing sub-units of the described registration in the described image storage unit of described characteristic image recognition system.
In the brightness characteristic quantity extracting method of described characteristic image, indicate in the step, described standard feature image is cut apart sign according to the position with digital mode by described sign unit at described position.In fact also can indicate in the mode of letter, but indicate, combine with the brightness characteristic quantity sign than being easier to digital mode.
In the brightness characteristic quantity extracting method of described characteristic image, indicate in the step at described position, described standard feature image is cut apart sign by described sign unit according to the position, and described position comprises face, eyebrow, eyes, nose, chin and the cheekbone of face.Usually when discerning, the position of face image comparison mainly is eyes, nose and face.And in some special circumstances, for example, person to be identified wear glasses or the situation of mouth mask under, also can select to want the position discerned voluntarily by person to be identified.
In the brightness characteristic quantity extracting method of described characteristic image, in described calculation procedure, described each pixel groups added up around the counting of pixel obtain a final brightness value, this final brightness value is distributed to each object pixel in the described object pixel group, and, if described final brightness value is not more than+and 2 or be not less than-2, then described final brightness value is set at 0, obtain the brightness characteristic quantity of each object pixel thus.When final brightness value be not more than+2 or when being not less than-2, that is to say, when final brightness value is 0,1 or-1 o'clock, can directly described final brightness value be set at 0, this illustrates that it is not very greatly that this object pixel (object pixel group) brightness on every side changes.
The present invention also provides a kind of recognition methods of characteristic image, may further comprise the steps:
Registration image input step is input to characteristic image to be registered in the described image storage unit of described characteristic image recognition system by camera;
Set-up procedure, with the characteristic image stored by the adjustment of described adjustment cut cells and be cut into the standard feature image of direction, the certain standard of size conforms;
The position indicates step, and described standard feature image is cut apart sign by described sign unit according to the position;
Extraction step extracts the brightness characteristic quantity of each station diagram picture with described brightness characteristic quantity extraction unit to each the station diagram picture that is indicated;
Storing step is stored in described brightness characteristic quantity in the described storage unit;
Wherein, described extraction step comprises:
Identification step is discerned the brightness value of each pixel in each station diagram picture;
First comparison step, a pixel in the extract part image is as object pixel, all pixels institute that will be adjacent with this object pixel as object pixel around pixel, calculate each object pixel around the luminance difference between pixel and the object pixel, if described luminance difference be no more than described object pixel brightness ± 20%, then should be classified as an object pixel group around pixel and described object pixel;
Second comparison step, all pixels that will be adjacent with the described object pixel group that obtains in described first comparison step as pixel groups around pixel, calculate each pixel groups around the luminance difference between pixel and the described object pixel that in described first comparison step, extracts, if described luminance difference be no more than described object pixel brightness+100%, be+1 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness+100%, be+2 around pixel counts then with this pixel groups; If described luminance difference be no more than described object pixel brightness-50%, be 0 around pixel counts then with this pixel groups; If described luminance difference surpass described object pixel brightness-50%, be-1 around pixel counts then with this pixel groups;
Calculation procedure, described each pixel groups added up around the counting of pixel obtains a final brightness value, and this final brightness value is distributed to each object pixel in the described object pixel group, obtains the brightness characteristic quantity of each object pixel thus;
Determining step, order is extracted the one other pixel outside the object pixel group, as object pixel, repeats first comparison step, second comparison step and calculation procedure, and all pixels in the station diagram picture all obtain the brightness value;
Image input step to be identified is input to characteristic image to be identified in the described image storage unit of described characteristic image recognition system by camera;
Repeat above-mentioned set-up procedure, position sign step, extraction step and storing step, thereby obtain the brightness characteristic quantity of characteristic image to be identified;
The characteristic portion of choosing according to the user more than three or from image storage unit, extract the brightness characteristic quantity of characteristic image to be identified at described position respectively according to a plurality of positions that described image identification system is set and the brightness characteristic quantity of the characteristic image of registration;
The brightness characteristic quantity of the characteristic image of the brightness characteristic quantity of the characteristic image described to be identified that extracted and described registration is compared,, then be judged to be characteristic image to be identified by identification if both are similar; Both are not similar else if, then are judged to be characteristic image to be identified not by identification.
In the recognition methods of described characteristic image, comprise at least in the characteristic portion more than three that described user chooses face face, eyebrow, eyes, nose, chin and cheekbone one of them.
In the brightness characteristic quantity extracting method of described characteristic image, in described calculation procedure, described each pixel groups added up around the counting of pixel obtain a final brightness value, this final brightness value is distributed to each object pixel in the described object pixel group, and, if described final brightness value is not more than+and 2 or be not less than-2, then described final brightness value is set at 0, obtain the brightness characteristic quantity of each object pixel thus.
In the brightness characteristic quantity extracting method of described characteristic image, in described first comparison step, if described luminance difference be no more than described object pixel brightness ± 10% o'clock, then should be classified as an object pixel group around pixel and described object pixel.
The multiple functional structure and the embodiment that are disclosed among the present invention all obtain embodying and protection by claim, and any resulting enlightenment of drawings and Examples shown in according to the present invention is among the scope that all falls into the present invention and protected.