CN101272505A - Pick-up device and pick-up method - Google Patents
Pick-up device and pick-up method Download PDFInfo
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- CN101272505A CN101272505A CNA2008100837716A CN200810083771A CN101272505A CN 101272505 A CN101272505 A CN 101272505A CN A2008100837716 A CNA2008100837716 A CN A2008100837716A CN 200810083771 A CN200810083771 A CN 200810083771A CN 101272505 A CN101272505 A CN 101272505A
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Abstract
This invention refers to camera device; especially a camera device and a method for controlling white balance. In order to reduce the color faults that the skin gets extremely pale or slant red, the invention provides following processing proposals: S1: reading appointed portion of image or the whole R, G, B signal integral value; S2: calculating WB evaluation value R/G gain and B/G gain; S3: pointing the obtained WB evaluation of estimate on color space using R/G and B/G as axes to perform whit detection; S4: judging light source sort according to the white detection; obtaining average of WB compensation value, and calculating and determining AWB calculation gain of one picture; S5: obtaining WB evaluation of estimate of detected face area on color space; S6: obtaining face calculation gain from WB evaluation value of the face area and replacing AWB calculation gain in S4, and performing face detection compensation.
Description
Technical field
The present invention relates to camera heads such as digital camera, relate in particular to camera head and the image capture method of carrying out automatic white balance control.
Background technology
In the past, camera head at video camera, the one-piece type video camera of VTR and electronic still video camera etc., in the attached camera head of person's portable terminal, for color reproduction stably when colour is made a video recording, carry out automatic white balance (hereinafter referred to as AWB) and handle, in order on the fathogram picture, to reappear the part that is white in color on the human body in the subject.
Usually, realize that the control method of AWB is, extracting white portion from subject is the achromatization part, calculates the WB offset according to the color information that extracts the zone.Such as, be divided into the picture in 256 zones to one with 16 * 16 five equilibriums, calculate R, G, B signal integration value in each zone, try to achieve ratio R/G, the B/G of R in each this cut zone, B signal integration value and G signal integration value then.
Secondly, with the ratio of 256 integrated values obtaining, be that transverse axis, B/G are that the color space of the longitudinal axis is to get ready on the white balance space with R/G, carry out white detection according to the distribution of the ratio of these integrated values.In order to carry out white detection, perform in advance changing the colour temperature of light source on the color space, for example the black body radiation track the during colour temperature of light source such as sunlight or tungsten light is as the preparation with reference to gain, 256 controlling values getting ready are contrasted this reference gain, can realize the white detection under the various light sources thus.
According to the light source kind in this white detection judgement subject, judge the light source that obtains relatively, white balance gain (WB offset) and each pixel are multiplied each other, make the ratio of integrated value of R, G, B signal become R: G: B=1: 1: 1, to realize white balance (WB) compensation.This method is based on people's color adaptation principle, promptly based on the hypothesis of so-called color adaptation, that is to say, even if under different light source irradiation, the thing of white always is seen as white.
Therefore, so-called AWB is when integral body is taken as the benchmark subject for the picture of white, can realize R signal, G signal, the B signal of image pickup signal are adjusted to the adjustment action that equates the output level.On level terms for the output that makes R signal, G signal, B signal, R signal, G signal, B signal be multiply by coefficient respectively, this coefficient is the white balance coefficient, also is referred to as the white balance gain.
But, there is following shortcoming in this method, promptly in subject, there is not the achromatization part, perhaps color is almost arranged partly is under the occupied situation of object color to subject, can not carry out white detection, perhaps the white detection precision reduces, and its result causes carrying out wrong white balance control.Can enumerate such problem by concrete example, under the light source of high colour temperature,, become to seem pale thereby people's skin compensated because people's colour of skin brightness strengthens, and it is achromatization with the white that people's skin color is judged as under the low color temperature light sources that mistake has taken place.Also have, such as forest with the bigger occasion of green proportion under, the erroneous judgement that light source is judged as fluorescent lamp can take place to miss.
So wrong white balance control is called as color fault (color failure).Below exemplify out the example of the white balance control that can alleviate the color fault.
At patent documentation 1 is that the spy opens in the 2004-64676 communique, even disclose a kind of camera head of suitably controlling white balance of when electronic zoom is made a video recording, also taking pains, this camera head extracts the feature that is used for white balance control according to the zone on the imaging apparatus of taking with camera head and the selected zoom of the choice device viewing area of zoom area.
At patent documentation 2 is that the spy opens in the 2004-312139 communique, disclose a kind of take pains solve mistake and will be judged as white under the low colour temperature in the colour of skin of taking under the high colour temperature, thereby make the camera head of the problem that people's the colour of skin becomes white partially.Patent documentation 2 disclosed camera heads are selected people's the colour of skin by the operator in shooting picture, and carry out the color evaluation in selected detection block, in order to set white balance.Like this, even if fail to carry out white detection and be the AWB reliability when low, according to this patent documentation 2, also can such as, as long as knowing selecteed detection block is the colour of skin, just can be by utilizing the color information in this surveyed area, setting with the colour of skin is the white balance that target is promptly reappeared the colour of skin, has the effect that the colour of skin that prevents the people becomes pale.
But,, when not existing white to be achromatization in the whole image, can not carry out above-mentioned white and extract, thereby still have the problem that can not suitably set white balance for above-mentioned patent documentation 1 disclosed camera head in the past.There is the problem that the color fault takes place in addition, such as being main subject with the personage at Portrait etc., especially make whole image all exist under the such situation of people's skin carrying out electronic zoom, the white of low colour temperature aspect can take place people's skin is thought by mistake, thereby take the skin color to such an extent that whiten, its result causes people's skin to seem pale.
In patent documentation 2, the operator must be with specifying skin color part, if each shooting all will be carried out such operation then can lose the opportunity of tripping someway.
In addition, alleviating by white balance on the color fault this point of skin color, though the purpose of patent documentation 2 and purpose of the present invention are similar, but the present invention utilizes the color information in detected face zone to alleviate to take place the become color fault of red partially or inclined to one side indigo plant and so on of people's skin, and judges or the notion of erroneous judgement skin color has nothing to do.Therefore, alleviating on the principle and method that the color fault adopted, the present invention is different from patent documentation 2.
In patent documentation 4, the shape of carry out extracting main subjects such as personage out is as the zone of the photometry/colour examining that is used to carry out main subject, and the measured value decision of calculating for each cut zone respectively increases the weight of coefficient.For example to 16 * 16 cut zone, by utilizing the shaped position information of main subjects such as face, decision is with respect to the emphasis regions in each cut zone.
And then decision is with respect to the coefficient that increases the weight of of each emphasis regions, and calculating increases the weight of the evaluation value of the evaluation value of coefficient as AEAWB calculating.
The AEAWB control of the additional main subject evaluation value of more than attaching most importance to.According to the above, need increase the weight of for main subject, emphasis regions such as the hair zones of considering detected main subject, skin zone, outer peripheral areas are perhaps arranged.
When there was the achromatization part simultaneously in picture piece inside and the color part is arranged, said method was considered to be effective in the method that reduces the color fault.But when picture piece inside only has the color part, just be difficult to the aberration of typical value and the aberration of character pixel are made comparisons.In addition, for the influence of light source mistake can take place will have color to be judged as achromatization, so just can't solve the problem of color fault.
Also has following technology in addition.Expectation for the operator obtains the artistic effect intention, deliberately setting is departed from white balance or the like.In this case, RAW data for image processing first being processed such as white balance processing, promptly carry out minimal image processing to having carried out the later initial data of A/D conversion from the signal output of CCD, and these data are stored, then according to the image processing parameter of individual hobby, comprise white balance, with PC etc. with RAW data reproduction image.
But,, can list following several problems for preserving RAW data ground method.
1) compare with jpeg data, the RAW data capacity is big, therefore needs mass storage device.
2) must possess the device that reproduces the RAW data image.Utilizing its original purpose of RAW data is to be the concrete image setting of realizing that the operator has a liking for, but can conclude also do not exist at present support RAW data video picture function and be expected to achieve the above object camera.Therefore, essentially must be with the software of special reproduced image such as computer applied algorithm, on the basis of having set the desired concrete image quality parameter of operator, manifest processing.
3) must have the professional knowledge of relevant reproduced image of height.
Therefore, above-described camera for the user of light enjoyment, is not perhaps also got used to the operator that operates, and the difficulty of its function is higher.
The invention is intended to solve the problem of above-mentioned conventional art, and be purpose with camera head and the image capture method that the white balance control that can realize reducing the color fault is provided.That is, even adopting conventional art can make under such light source irradiation that people's skin seems pale or red partially, the present invention also can not cause people's skin to seem extremely pale or red partially.
Summary of the invention
In order to achieve the above object, the invention provides following camera head and image capture method.
(1) a kind of camera head has: image unit is transformed into electrical picture signal with optical imagery; The chrominance signal extracting unit, according to the color information of described picture signal, extraction is used for the chrominance signal of white balance control and launches on color space; The chrominance signal selected cell is selected chrominance signal on color space; And white balance control unit, carry out white balance control with the offset of calculating according to the chrominance signal on the color space, it is characterized by, possesses the face detecting unit, from picture signal, detect the position in personage's face zone, selection is corresponding to the chrominance signal on the color space of detected face region extraction, and the calculated value according to calculating from the chrominance signal of having selected changes the offset that is used to carry out white balance control and calculates.This camera head can reduce and goes white or too red color fault.
(2) according to (1) described camera head, it is characterized by, the chrominance signal extracting unit is on the cut zone of a picture that has extracted chrominance signal, from R, the G of chrominance signal, B signal, obtain the integrated value of each cut zone respectively, calculate the ratio B/G of the ratio R/G of each regional R and G and B and G; Perhaps, serving as axle with R/G and B/G and launching on the color space of the chrominance signal that the chrominance signal extracting unit extracted, change the offset be used to carry out described white balance control and calculate, make distance between this offset and the calculated value of from the regional selected chrominance signal of corresponding detected face, calculating in prescribed limit; Perhaps, serving as axle with R/G and B/G and launching on the color space of the chrominance signal that the chrominance signal extracting unit extracted, offset of calculating and distance from being connected with straight line between the calculated value of calculating corresponding to the selected chrominance signal in detected face zone for being used for carrying out described white balance control, ratio with regulation carries out extrapolation or interpolation, offset is changed into the position of this extrapolation or interpolation.Like this, offset on the color space and the distance between the calculated value can be controlled in the prescribed limit, thereby the tone sensation that has kept the face zone to a certain extent, and, by the offset and the distance between the calculated value that connect with straight line being carried out extrapolation or interpolation with requirement ratio, can on the binary space, ask for calculated value simply, change offset according to this calculated value, rarely seriously lose white balance, reduced going white or red partially color fault.
(3) according to (2) described camera head, it is characterized by, the face detecting unit detects big face zone with prescribed level; Perhaps, when the face detecting unit detects a plurality of faces zone, from corresponding to calculating calculated value the regioselective chrominance signal of each face, and obtain the average of this calculated value, change and be used to carry out the offset that white balance control is calculated according to obtaining average calculated value; Perhaps, has main subject decision unit, the main subject of decision from the detected a plurality of faces of face detecting unit zone, and, change into the offset that carries out white balance control and calculate according to from corresponding to the calculated value of calculating the regioselective chrominance signal of the face of fixed main subject; And then, main subject decision unit according in camera head, done in advance login the face area data determine main subject.Like this, according to the above, integral image is hour relatively when face zone, can make the compensation of integral image have precedence over the compensation of face, each calculated value by using detected a plurality of faces zone average set preferred relatively offset to all face zones, and then, select main subject, preferential subject is set the preferred compensation value, thereupon, according to the face area data of identification people face, under situation about may discern,, set the preferred compensation value as main subject.
(4) a kind of image capture method, comprise the processing that optical imagery is converted to electrical picture signal, color information according to picture signal extracts chrominance signal that is used for white balance control and the processing that this chrominance signal is launched on color space, select the processing of chrominance signal from color space, and in order to carry out white balance control, obtain the processing of calculating offset according to the described chrominance signal on the described color space, it is characterized by, also comprise the processing of the position of from described picture signal, detecting personage's face zone, selection is corresponding to the chrominance signal on the color space of detected face region extraction, according to the calculated value of from selected chrominance signal, calculating, change the offset that is used to carry out described white balance control and calculates, and then carry out white balance control according to altered offset.Can reduce like this and go white or red partially color fault.
The present invention has following effect, that is, by utilizing the chrominance signal in face zone, even be under the light source irradiation that the skin that can make the people seems pale or red partially, also can control by white balance, reduces face and becomes pale or red partially color fault.
Description of drawings
Fig. 1 has shown the digital camera outward appearance of embodiment of the present invention, and A is that top view, B are that front view, C are rearview.
Fig. 2 is the schematic configuration schematic diagram of functional module that shows the digital camera inside of present embodiment.
Fig. 3 is the WB control method flow chart of present embodiment.
Fig. 4 is the distribution map that exemplifies the WB evaluation of estimate of the cut zone of getting present embodiment on color space ready.
Fig. 5 is the figure that gets face zone WB evaluation of estimate, face calculated gains and the AWB calculated gains of present embodiment on color space ready.
Fig. 6 is the schematic diagram that is used to illustrate present embodiment distance between face calculated gains on the color space and AWB calculated gains.
Fig. 7 shows present embodiment the face calculated gains on the color space and figure of AWB calculated gains when the face compensation is pale.
Fig. 8 has exemplified present embodiment at the schematic diagram that face is compensated into when red partially on color space by face calculated gains compensation AWB calculated gains.
Fig. 9 is the generalized schematic that the face of present embodiment detects compensation.
Figure 10 is in order to the schematic diagram of explanation present embodiment in the scope of carrying out face detection compensation along the black body radiation track.
Embodiment
Below, with reference to the accompanying drawings embodiments of the present invention are elaborated.
Fig. 1 has shown that the camera system of embodiment of the present invention is the outward appearance of digital camera, and A is that top view, B are that front view, C are rearview.In Figure 1A, B, C, the top of camera body is provided with release-push (being so-called shutter release button) SW1, pattern dish SW2 and secondary LCD is secondary LCD 1.The camera body front is provided with photoflash lamp illuminating part 3, range finding assembly 5 and remote controller light accepting part 6.In addition, optical finder 4 is positioned at the front of this camera body to object plane, barrel assembly 7 object plane also is provided with towards the front.Barrel assembly 7 includes pick-up lens.
The camera body back side is provided with that mains switch SW13, LCD monitor 10, AF LED are that automatic focus light-emitting diode 8, photoflash lamp LED 9, wide-angle direction focus on button SW3, the direction focusing button SW4 that looks in the distance, auto heterodyne timer/cancel button SW5, menu button SW6, go up mobile photoflash lamp button SW7, the button SW8 that moves right, monitor switch SW9, down mobile microspur button SW10, move left image and examine button SW11 and carry out button SW12.
The major part of optical finder 4 is concealed in camera body inside, but its visual surface is set on the back portion of camera.Be provided with storage card/battery compartment lid 2 at the camera body sidepiece.Because of the general utility functions of these parts widely known to, so omit its detailed description at this.
In addition, camera head outward appearance of the present invention might not be confined to the outward appearance shown in Figure 1A, B, the C, also can have other outward appearances.Though adopting the image pickup mode of digital still image camera in the present embodiment is that camera system is as image-input device, but be not limited to such camera system, also can handheld scanner+PAD etc. have the image processing system of image-input device and image processing apparatus and display unit.
Fig. 2 is the generalized schematic of the digital camera inner function module structure of embodiment of the present invention.In Fig. 2, for the same symbolic representation of circuit element employing of the above-mentioned mechanical part shown in Figure 1 of operation.The camera head of present embodiment possesses: eyepiece component 71 is used for the optical imagery of subject is carried out light harvesting; Aperture portion 72 is used for the light beam by lens assembly 71 light harvestings is shunk focusing; Motor driver 75 is used for moving not shown a plurality of lens and checks and approves focus, perhaps drives aperture portion 72, perhaps drives not shown mechanical shutter; CCD (Charge Coupled Device, charge coupled cell) 101, input also is transformed to analog picture signal with this optical imagery by the optical imagery of lens assembly 71 and aperture portion 72.
CCD101 converts shot object image to picture signal and outputs among the F/E-IC (preposition loop-integrated circuit) 102.F/E-IC 102 possesses: CDS (Correlated Double Sampling, correlated double sampling) 1021, from reducing the impurity signal from sampling the picture signal of CCD101; AGC (automatic gain control) 1022, the output gain of adjustment CDS1021; A/D converter 1023, the analog picture signal that AGC1022 is exported is transformed into data image signal; TG (time signal generator) 1024, the time of origin signal is in order to the action moment of indication A/D converter 1023.
The camera head of present embodiment also possesses: SDRAM103 is an image record device, and records photographing image and storage are through the image of image processing such as the data of JPEG packed data or demonstration usefulness etc.; Signal processing IC 104 carries out image processing according to the picture signal and the image parameter of input; Operating portion 105 possesses the button that the user operates this device usefulness, release-push SW1 as shown in Figure 1 etc.; ROM106 is used to deposit control program or the data of controlling following CPU1043; Storage card 107 is used to deposit the view data by 1045 compressions of following compand portion.Also have LCD display (referring to Fig. 1 C) 10, be used to show view data by following demonstration output control part 1046.
Signal processing IC 104 possesses: CCD interface portion (I/F) 1041, in the CCD101 output signal same period, obtain and the corresponding view data of the signal same period; Storage control 1042 is to SDRAM103 transmitted image data; CPU1043 totally controls or extracts color information etc. according to the control program of depositing among the ROM106 to this device; YUV transformation component (data mode converting means) 1044 is transformed into the data format of the YUV that can show or can store with the view data of input; Compand portion 1045 compresses the view data of handling through signal processing IC 104, and perhaps expansion returns to the original digital image data size.
In addition, also possess: show output control part 1046, control comes from the demonstration output of signal processing IC 104, and it is outputed among the LCD that is built in this device; Image size handling part 1047 changes image file size according to the amount of capacity that shows or store; Storage medium I/F (interface portion) 1048 neutralizes data compression process in the enlarged portion 1045 that contracts with JEPG storage time control, perhaps writes the processing that writes of image data storage card 107.
Below, the elemental motion of the digital camera of present embodiment is described.Through be subjected to the subject image of light after lens assembly 71 in the barrel assembly 7 and the aperture portion 72 at CCD101, after carrying out correlated double sampling removal of images impurity signal by CDS1021, adjust gain by AGC1022, and then be transformed into digital image signal input signal processing IC 104 by A/D converter 1023.In signal processing IC 104, CCDI/F1041 exports the signal same period to CCD101, and obtains simultaneously and the corresponding view data of the signal same period.
Storage control 1042 needs the view data of preservation to the SDRAM103 transmission.CPU1043 does overall control according to the control program of depositing among the ROM106 to this device.YUV transformation component 1044 is transformed into the yuv data form that can show and write down with the view data of importing under the control of CPU1043.Compand portion 1045 via controllers 1042 are accepted the view data handled through signal processing ICs 104, and after its expansion returned to the original image file size, send storage control 1042 back to.
Demonstration output control part 1046 is accepted to export and be presented on the LCD display 10 from the demonstration of signal processing IC 104 through storage control 1042.Image size handling part 1047 is obtained view data through storage control 1042, changes the size of image file according to the amount of capacity that shows or store.Storage medium I/F1048 obtains view data through storage control 1042, and this view data write storage card 107, perhaps further reads image data from storage card 107, and then, neutralize data compression process in the enlarged portion 1045 that contracts preserving time control with JPEG.
In addition, in SDRAM103, possess memory and the memory of data of maintenance demonstration usefulness and the RAM that CPU1043 uses that is used for temporarily preserving view data and JPEG packed data.
Below, taking the static example that is depicted as, the characteristic action that the digital camera of present embodiment is had is elaborated.
When pressing the button of release-push SW1, the AF function begins action prior to shooting.Like this, on one side the mountain-climbing AF that seeks maximum-contrast such as mobile focus lamp on one side such as handles at subject in focus.
Above-mentioned processing is to utilize the high frequency composition in image signal G signal or the brightness value Y-signal to make the AF evaluation, the focus lamp position when calculating this AF evaluation of estimate for maximum, the processing of mobile focus lamp then.About obtaining the zone of AF evaluation of estimate, have the multizone AF that subject is considered a plurality of zones, perhaps only consider the regional AF of point in part zone or the like.According to the AF evaluation of estimate, calculate the focal position that is suitable for shooting picture, focus lamp is moved on on this aspect.Focus lamp can be according to the instruction of CPU1043, moves it with the motor driver 75 of lens assembly 71.
Then, carry out the electronic shutter setting of static picture usefulness, calculating/setting of AGC1022 and the calculating/setting of focus portion 72, then carry out AE (Auto Exposure) and handle and recording exposure.Electronic shutter is set and AGC1022 sets and can carry out respectively by TG1024 and the F/E-IC102 that controls the CCD101 driving according to the instruction from CPU1043.When being used for the end exposure of static picture, mechanical shutter is closed, and is exported the RAW data of static picture usefulness by CCD101.Be furnished with discharge first handle promptly half by and discharge second and handle the camera system of promptly pressing entirely, generally carry out the calculating of AF or AE discharging first control when handling, discharging the exposure that second executive logging of control when handling is used.
The RAW data of static picture usefulness are taken among the SDRAM103 through signal processing IC 104.In signal processing IC 104, these RAW data are carried out image processing such as black level compensation, the compensation of defective picture element and shade compensation, then write among the SDRAM103 with the RAW data format.If staggered the transmission then writes among the SDRAM103 with the RAW data format by the dateout that repeatedly transmits CCD.
Write all the RAW data among the SDRAM103, once more by signal processing IC 104, between mending, the calculating of WB gain multiplied, gamma compensated and RGB handle, then carry out various image processing such as emphasizing contour, color setting at YUV transformation component 1044, meanwhile be transformed into the yuv data form of briliancy/color difference signal, return among the SDRAM103.About the white balance control that the present invention relates to, a piece of writing is described in detail in the back.
The data file that is transformed into yuv format is the full-scale CCD of being size, if image need carry out record with the size less than the CCD size, then by the big or small handling part 1047 downscaled images files of the image of signal processing IC 104.The YUV image file that the preparation of handling through image size handling part 1047 is used to note down, form according to the rules compresses processing in compand portion 1045, such as, carry out the JEPG compression and handle.Compressed file after JPEG compression returns SDRAM103, processing such as notes before having carried out appending after storage control 1042 be saved in the recording medium such as storage card 107.It more than is the general processing of taking static picture.
Secondly, with reference to the accompanying drawings the white balance in the present embodiment (WB) control is described.Fig. 3 is for showing the flow chart of WB control method in the present embodiment.In flow chart shown in Figure 3, promptly be that the elemental motion of AWB control in the past is algorithm to calculating processing till the AWB offset (AWB calculated gains).
At first simple declaration is done in this elemental motion.
Treatment S 1: through lens assembly shown in Figure 2 71, shot object image incides CCD101.After CCD101 converts shot object image the signal of telecommunication to and is simulated image data, the simulated image data of output R, G, B signal.This simulated image data becomes data image signal by A/D converter 1023 with R, G, the B conversion of signals of color information.DID through conversion is kept in the not shown frame memory.At this moment, signal processing IC 104 reads in the specified portions calculated when obtaining DID or image all R, G, each integrated value of B signal in CCD-I/F1041.
Treatment S 2: control part CPU1043 reads the integrated value of this R, G, B signal, and the WB evaluation of estimate that detected characteristics and calculating can form suitable white balance is R/G gain and B/G gain.
For example, in treatment S 1, a picture is cut apart 256 zones of formation with 16 * 16, each cut zone is calculated the integrated value of R, G, B signal respectively, by ratio, i.e. R/G gain and the B/G gain of R signal integration value and B signal integration value in treatment S 2 these each cut zone of calculating with G signal integration value.
Treatment S 3: on above-mentioned basis, extract white portion and be the achromatization part from subject as detected feature, calculating the AWB evaluation of estimate from the color information that extracts the zone is chrominance signal.That is to say, be the WB evaluation of estimate with the ratio of 256 integrated values obtaining, gets ready on the color space that with R/G and B/G is axle, carries out white detection from this distribution.Carry out white detection and need be prepared in advance black body radiation track when to change light source on color space be the colour temperature of sunlight or tungsten light as with reference to gain, then 256 controlling values are contrasted this reference gain, be implemented in the white detection under the various light sources.
Treatment S 4: the light source kind of judging subject by white detection, acquisition is with respect to the light source of being judged, the integration ratio of R, G, B signal becomes R: G: B=1: 1: 1 WB gain is the WB offset, and this WB gain is multiplied each other with each picture element respectively, realizes the WB compensation thus.According to the average computation of the WB offset of trying to achieve like this and determine that the AWB offset of whole image is the AWB calculated gains.In addition, in YUV transformation component 1044, R, G, B signal data be transformed into briliancy Y and aberration Cb, Cr data and output in the frame memory.When carrying out this image transform, YUV transformation component 1044 is set the AWB offset by CPU1043.
Treatment S 5: to S3, obtain WB evaluation of estimate on the color space for the face zone of the personage in the detected picture from picture signal as above-mentioned treatment S 1.About asking for the method for the WB evaluation of estimate that detects the face zone, can handle according to the detection in face zone, such as with upper left, have go up, lower-left, bottom right 4 point coordinates represent the face zone, be mapped in above-mentioned 16 * 16 districts with this 4 point coordinates, from this regional R, G, B signal integration value, calculate the WB evaluation of estimate.
Treatment S 6: calculate the face calculated gains from the calculated value that on average obtains of described face zone WB evaluation of estimate, change the AWB calculated gains that obtains in treatment S 4, compensate, promptly face detects compensation.In addition, the WB evaluation of estimate in above-mentioned face zone is according to the size in face zone and difference, at least more than 1.
Size differences according between detected face zone and the cut zone that is used to obtain the WB evaluation of estimate judges whether to obtain the WB evaluation of estimate in the face zone, can handle on the basis of consideration compensation effect like this.That is, when face zone hour, there is no need the face zone is compensated processing, thereby not with face zone object and adopt the AWB offset of a picture by way of compensation.
In addition, the detection method in relevant face zone has proposed various algorithms (algorithm) scheme in the known technology.Though the present invention does not specify which kind of method of employing, but in detected face zone, owing to be included in eyes on the face, face in described upper left, upper right, lower-left, bottom right 4 point coordinates, sensuously different with the skin of face at tone, thereby it is less to obtain the face regional extent of WB evaluation of estimate.
Also have, in according to the detected a plurality of faces of face method for detecting area zone, not only can be automatically with the face zone of maximum or be positioned near the picture center the face zone handle as main subject, and can determine main subject to handle according to the device of selecting arbitrarily by operating portion to determine.In addition, can also use the face zone and detect correlation technique, from a picture, specify the personage who has done login, the authentication authorization and accounting technology, face area information by logining detected personage is a feature, specifies the personage of login formerly with characteristic, and only this personage is handled.
Fig. 4 shown in the present embodiment a picture segmentation is become 256 zones after, on the color space that with R/G and B/G is axle, get each regional WB evaluation of estimate ready and be a gain example of gained distribution map of R/G gain and B/G.
Signal processing IC 104 is according to distribute light source when judging shooting of the WB evaluation of estimate of each cut zone.Light source judges it is by utilizing the distribution of achromatization WB evaluation of estimate partly on the black body radiation track to realize.Therefore for example, in the example of Fig. 4, in that (R/G, B/G)=(1.2,0.6) the WB evaluation of estimate that distributes near the black body radiation geometric locus is more, can infer that light source is a blue-light source.Then, to R with 1.2 times of compensation multiply each other, B multiplies each other with 0.6 times of compensation, is used for the WB compensation as YUV transformation component 1044, makes this regional signal data become grey, the vision near the people is adjusted in white balance like this.
In addition, distribute,, need to determine to cooperate the reference of the WB evaluation of estimate of CCD101 for this reason even identical illumination, identical subject, WB evaluation of estimate also can be different for the branch photo sensitivity of CCD101.In the camera head of reality, for reducing the color fault or catering to the purpose that color processing is carried out in user's hobby, the AWB offset is that the algorithm of WB is just made final decision after all processing.Can also adopt the predefined set point that has according to digital camera and decide the AWB offset such as various imaging conditions such as indoor, outdoor and flash of light shootings.
For in the WB control condition that the color fault causes people's the colour of skin to become pale or red partially taking place, can describe with the WB evaluation of estimate in face zone and the relation between the final WB offset of setting.That is to say that R/G gain and the B/G with the final AWB offset of setting gains between the two in the R/G of the WB in face zone evaluation of estimate gain and B/G gain, and be if there is no poor, face can bleach and promptly become pale, on the contrary, if exist bigger poor, the red partially or inclined to one side indigo plant of face then.
To this, the present invention carries out following control.That is, to depending on the face calculated gains of face zone WB evaluation of estimate, and the relation between the AWB calculated gains of asking for AWB offset algorithm that depends on compares, and compensates the AWB calculated gains with the face calculated gains, finally sets the AWB offset thus.
Fig. 5 is to be on the color space of axle with R/G and B/G, with the WB evaluation of estimate in detected face zone and the figure that gets ready according to the AWB calculated gains that algorithm determined of asking for the AWB offset.In example shown in Figure 5, the face calculated gains that is determined by face zone WB evaluation of estimate is that (R/G, B/G)=(0.4,1.2), the AWB calculated gains is (0.9,0.9).
Fig. 6 is that relative Fig. 5 considers that the face in face zone on the color space calculates increment and AWB calculates the figure at interval between the increment.Be called for short this for convenience in the present embodiment and be spaced apart distance.Face among Fig. 6 on the color space calculates the straight line approximate distance x between increment and the AWB calculating increment, calculates by following formula (1),
Obtaining x thus is 0.5283.
Fig. 7 compensates into face for example when pale, shown face calculated gains and AWB calculated gains on color space this moment among the figure.Since 0.2 less than between the face calculated gains in above-mentioned face zone and the AWB calculated gains apart from x, so adopt the AWB calculated gains can make to go white as the AWB offset.Fig. 8 compensates into face for example when red partially, shown face calculated gains and AWB calculated gains on color space this moment among this figure.
With reference to figure 8, illustrate calculated gains with face calculated gains compensation AWB, make the color in face zone can not become red partially.As shown in Figure 8, on the color space with the approximate distance of straight line be 1.0 greater than between the face calculated gains in above-mentioned face zone and the AWB calculated gains apart from x, for this reason, if can make face red partially as final AWB offset the AWB calculated gains.On the other hand, if the distance after the compensation is 0.7, it is red partially that this difference can reduce face.
Below, the compensation method of AWB offset in the present embodiment is described.
Fig. 9 detects the generalized schematic of the compensation way of thinking for face.In Fig. 9, the center of circle is the face calculated gains, and the point of cross mark is the AWB calculated gains, and the spider lable point is respectively relative AWB and calculates the resulting AWB calculated gains of valued added applications face detection compensation.The optimum condition of face regional color reproducibility is, distance is 0.4 to 0.8 between face calculated gains and the AWB calculated gains, and concrete lower range is 0.4 to 0.6, upper range position 0.6 to 0.8, and preferred 0.5 to 0.7 scope is carried out following compensation according to this distance.Above-mentioned distance values is in order to make the face regional color reproducibility in the photographic images be in the state that is more preferably, by experiment the numerical value of gained.
Corresponding to following the carrying out of compensation of distance between face calculated gains of trying to achieve on the above-mentioned color space and the AWB calculated gains,
(1) distance between face calculated gains and AWB calculated gains is 0.4 to 0.8, preferred 0.5 to 0.7 o'clock, with the AWB calculated gains as the AWB offset.
(2) distance between face calculated gains and AWB calculated gains is less than 0.4, preferably less than 0.5 o'clock, on the straight line that connects between face calculated gains and the AWB calculated gains, obtaining apart from face calculated gains position is 0.4 point, preferred 0.5 point is the AWB offset with this AWB calculated gains.
(3) distance between face calculated gains and AWB calculated gains is greater than 0.8, be preferably greater than at 0.7 o'clock, on the straight line that connects between face calculated gains and the AWB calculated gains, obtaining apart from face calculated gains position is 0.8 point, preferred 0.7 point is the AWB offset with this AWB calculated gains.
Specifically can make following simple operation, promptly, position with the face calculated gains is A, AWB calculated gains position is B, and this distance between the two is D, becomes with 0.4 under the condition of above-mentioned (2): D, preferred 0.5: D, connecting line AB is carried out the extrapolation point of extrapolation gained, under the condition of described (3), become: D, preferred 0.7: (D-0.7) carry out the interpolated point of interpolation with 0.8.
In the face calculated gains and distance of described compensation AWB calculated gains, black body radiation geometric locus on the color space perpendicular to this curve tangential direction, draws as being that major axis, the latter are that the distance range of the ellipse of minor axis compensates with the former.Concrete scope as shown in figure 10 is 0.4 to 0.8 along the distance of the transverse direction of black body radiation track, and promptly lower range is 0.4 to 0.6, upper range position 0.6 to 0.8, the distance of short-axis direction is 0.2 to 0.4, and promptly lower range is 0.2 to 0.3, upper range position 0.3 to 0.4.
In addition, when detecting a plurality of faces zone from a picture, the face calculated gains is obtained in each detected face zone, with these face calculated gains on average as the face calculated gains.
The above face detects compensation and has following effect:
(1) compares the AWB calculated gains of in the past from the WB evaluation of estimate, calculating,, can realize compensation simply as long as add the face calculated gains of obtaining in the WB evaluation of estimate that formerly from the face zone, obtains with AWB offset algorithm.In addition, the information reliability in detected face zone hour reduces controls such as control compensation degree easily.
(2) with AWB calculated gains and these two information decision AWB offsets of face calculated gains, can only do suitable white balance compensation like this, and extreme departing from can not take place in the WB of other non-main subjects to face.
No matter therefore the tone sensation that has kept the face zone when (3) the AWB offset being compensated, be that the face red partially or inclined to one side indigo plant that becomes can compensate.
Practicality of the present invention is that the bright camera head that relates to of this law and image capture method are by utilizing face The chrominance signal in zone is even so that be pale or partially red light source irradiation in the colour of skin that causes easily the people Lower, also can reduce the white balance control of color fault, supression goes white or is partially red. This law is bright to relate to the camera head such as digital camera, is particularly useful for automatic white balance control.
Claims (9)
1. camera head has:
Image unit is transformed into electrical picture signal with optical imagery;
The chrominance signal extracting unit, according to the color information in the described picture signal, extraction is used for the chrominance signal of white balance control and launches on color space;
The chrominance signal selected cell is selected chrominance signal on described color space;
The white balance control unit uses the offset of calculating according to the described chrominance signal on the described color space to carry out white balance control,
It is characterized by, possess the face detecting unit, from described picture signal, detect the position in personage's face zone,
Selection is corresponding to the chrominance signal on the described color space of detected described face region extraction, and the calculated value according to calculating from the described chrominance signal of having selected changes the offset that is used to carry out described white balance control and calculates.
2. camera head according to claim 1, it is characterized by, described chrominance signal extracting unit is on the cut zone of a picture that has extracted chrominance signal, from R, the G of described chrominance signal, B signal, obtain the integrated value of each cut zone respectively, the ratio B/G of the R that calculates each described zone and the ratio R/G of G and B and G.
3. according to claim 1 or 2 described camera heads, it is characterized by, serving as axle with R/G and B/G and launching on the color space of the chrominance signal that described chrominance signal extracting unit extracted, change the offset be used to carry out described white balance control and calculate, make this offset and from corresponding to the distance between the calculated value of calculating the regioselective chrominance signal of detected face in prescribed limit.
4. according to claim 1 or 2 described camera heads, it is characterized by, serving as axle with R/G and B/G and launching on the color space of the chrominance signal that described chrominance signal extracting unit extracted, offset of calculating and distance from being connected with straight line between the calculated value of calculating corresponding to the selected chrominance signal in detected face zone to being used for carrying out described white balance control, ratio with regulation carries out extrapolation or interpolation, and described offset is changed into the position of this extrapolation or interpolation.
5. according to any described camera head among the claim 1 to 4, it is characterized by, described face detecting unit detects big face zone with prescribed level.
6. according to any described camera head among the claim 1 to 5, it is characterized by, when described face detecting unit detects a plurality of faces zone, from corresponding to calculating calculated value the regioselective chrominance signal of each face, and obtain the average of this calculated value, be used to carry out the offset that white balance control is calculated according to obtaining average calculated value change.
7. according to any described camera head among the claim 1 to 5, it is characterized by, has main subject decision unit, the main subject of decision from the detected a plurality of faces of described face detecting unit zone, and, change the offset that is used to carry out white balance control and calculates according to the calculated value of from the selected chrominance signal in face zone, calculating corresponding to fixed described main subject.
8. camera head according to claim 7 is characterized by, and described main subject decision unit determines main subject according to the data in the face zone of having done login in advance in camera head.
9. image capture method comprises following processing:
Optical imagery is converted to the processing of electrical picture signal;
According to the color information of described picture signal, extract the chrominance signal be used for white balance control, and the processing that this chrominance signal is launched on color space;
Select the processing of chrominance signal from described color space; And,
In order to carry out white balance control, obtain the processing of the offset of calculating according to the described chrominance signal on the described color space,
It is characterized by, also comprise the processing of the position in the face zone of from described picture signal, detecting the personage,
Chrominance signal on the described color space that selection is extracted corresponding to detected described face zone, according to the calculated value of from the chrominance signal of described selection, calculating, change the offset that is used to carry out described white balance control and calculates, carry out white balance control according to described altered offset.
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| JP2007069824A JP2008236101A (en) | 2007-03-19 | 2007-03-19 | Imaging device and imaging method |
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2007
- 2007-03-19 JP JP2007069824A patent/JP2008236101A/en active Pending
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2008
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| CN101272505B (en) | 2010-06-02 |
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