CN101867828A - Multi-charge coupled device group self-adaptive imaging instrument of cambered optical structure and method thereof - Google Patents

Abstract

The invention relates to a multi-charge coupled device group self-adaptive imaging instrument of a cambered optical structure and a method thereof, belonging to a field of the image information acquisition and processing. By imitating an ommateum to adjust the nerve conduction mode with the change of the illumination under the condition of day alternates with night to obtain a self-adaptive imaging effect principle, the instrument uses a plurality of common charge coupled devices (CCD), corresponding auxiliary circuits and a neural processing algorithm to construct a biomimic self-adaptive adjustment imaging instrument. The imaging instrument has an imaging function of self adjusting fusion modes with the change of illumination conditions, can acquire a high-contrast image under a normal illumination condition, and also can acquire a high-brightness sensitive image under a weak illumination condition. The invention realizes high-definition surveillance and monitoring under the condition of day alternates with night, belonging to the image information acquisition and processing field.

Description

The multi-charge coupled apparatus group self-adaptive imaging instrument and the method for curved surface optical texture

One, technical field

The multi-charge coupled apparatus group self-adaptive imaging instrument and the method for curved surface optical texture of the present invention belong to image information acquisition and process field.

Two, background technology

In video scene supervision, industrial production monitoring etc. are used, not only need imageing sensor to have higher spatial resolution usually, also need imageing sensor under the darker situation of night or light, to get access to high-quality image information.Common imageing sensor all depends on extraneous illumination condition, and the reduction of lamp brightness certainly will have influence on imaging effect under night or other special weather situations.Though adopt at night usually and add the secondary light source of artificial light sources as imageing sensor, but the brightness range of this light source is limited, and the riding position of light source also can directly have influence on the imaging effect of transducer, causes characteristics such as image irradiation is inhomogeneous, for subsequent treatment has increased difficulty.Therefore how to make imager can have and be made for the key point that under different brightness conditions, obtains high quality graphic with the adaptive camera that is adjusted to of brightness.

At present on the hardware at the low-light (level) environment under the imageing sensor of imaging emerge in an endless stream, this class transducer is to improve imaging effect by the sensitivity that improves the CCD element basically.The development of domestic low-light (level) imageing sensor imager mainly divides three phases: colored/black self-switching type, low no-delay gate formula with telegraphy degree formula.Though these three kinds of cameras have solved low light to a certain extent according to the imaging problem under the condition, but have two big shortcomings: a shortcoming is to involve great expense, the low-light (level) camera of better performances adopts the object under the infrared lens induction half-light usually, but this will increase the cost of camera greatly, the another one shortcoming is that function is comparatively fixing, lack flexibility, promptly the low-light (level) index of this class imageing sensor is subjected to the qualification of CCD performance, does not have the ability of regulating with the illumination self adaptation.Adopt infrared lens low-light (level) imageing sensor under the normal illumination condition, to influence the definition of image owing to the infrared composition in the natural daylight; Therefore all there is certain limitation in the low-light-level imaging instrument on range of application.

On software, mainly contain traditional overall enhancement algorithms and local enhancement methods at the algorithm that improves the low-light (level) picture contrast.Overall situation enhancement algorithms mainly contains histogram equalization and contrast enhancement algorithms etc.Histogram equalizing method is the method that increases contrast indirectly, and this method is simple, and effect is obvious, but exists enhancing back image shortcomings such as details disappearance to occur.Thereby contrast enhancement process is the distance between the direct stretched pixels strengthens contrast, for the different zone of image, and the function that local detail can not self adaptation strengthens.In processing procedure, be regardless of simultaneously noise and detailed information, when strengthening image gray levels difference, make noise also be enhanced.Overall in addition enhancement algorithms is not suitable for the bigger situation of the even contrast variation's amplitude of uneven illumination at night.The method of partial gradient domain model is a kind of local method that improves contrast, the dynamic range that these class methods have effectively been compressed the uneven illumination image has increased the contrast of dark place simultaneously, but it is not obvious to the detail section reinforced effects that brightness is higher, these class methods are bigger than the Global Algorithm amount of calculation simultaneously, the computation complexity height.

Three, summary of the invention

The objective of the invention is at the high shortcomings such as popularization that are difficult to of illumination condition limitation, the cost of traditional low-light-level imaging instrument, the imitation compound eye changes the process of regulating neural amalgamation mode with external environment illumination brightness, cartridge based on the overlapping type compound eye of nerve merges mechanism, but adopts the multi-charge coupled apparatus assembly of imitative compound eye curved-surface structure to close imager of continuous monitoring round the clock and the method that the DSP+FPGA chip has made up a kind of self-adapting adjustment type of cheap whole day monitoring.

2, a kind of multi-charge coupled apparatus group self-adaptive imaging instrument of curved surface optical texture is characterized in that:

Comprise 3 identical CCD cameras, 3 are used for first kind DSP digital signal processing chip that luminance component separates with two color difference components, 1 and are used to finish the second class DSP digital signal processing chip, 3 programmable vision signal processing chips that are used for analog-to-digital conversion and system conversion, 3 electricity that multiple image merges and can wipe storage chip;

Above-mentioned 3 CCD closely link together, and being attached to a radius is on the curved surface of r, and the angle between adjacent two ommatidium optical axises is the curved-surface structure that θ ≈ art sin (D/r) constitutes imitative compound eye, and wherein r is the eye radius of compound eye, and D is the ommatidium diameter;

Above-mentioned 3 CCD cameras carry out preliminary treatment by the input end of analog signal that USB interface is connected to above-mentioned 3 programmable vision signal processing chips respectively; The state information of programmable vision signal processing chip is exported in the complex programmable logic device (CLPC) as control signal, data-signal then can be wiped storage chip through above-mentioned 3 electricity and be input to respectively in above-mentioned 3 first kind DSP digital signal processor core, and the control signal of 3 first kind DSP digital signal processing chips is input to 1 second class DSP digital signal processing chip as chip selection signal and enable signal.

2, utilize the self adaptive imaging method of the multi-charge coupled apparatus group self-adaptive imaging instrument realization of the described curved surface optical texture of claim 1, it is characterized in that may further comprise the steps:

(1), utilize the ommatidiums independent imagings respectively in three CCD cameras simulation compound eye, obtain three width of cloth ommatidium images;

(2), utilize the programmable vision signal processing chip respectively three secondary ommatidium images processes to be carried out the conversion of analog-to-digital conversion and standard;

(3), utilize three first kind DSP digital signal processing chips that three width of cloth ommatidium images are carried out separating of luminance component and two color difference components respectively;

(4), according to the characteristics of only luminance component being handled in the visual processes, extract the Y component of three secondary ommatidium images, together with the color difference components of not doing any processing after separating, be input to the multiple image fusion treatment that inspired by the biological compound eye cartridge jointly, concrete blending algorithm is as follows:

Step 1: establish I1, I2 and I3 and represent three secondary ommatidium images respectively, extract the luminance component of three width of cloth ommatidium images; , as with reference to image I2 and I3 are registrated on the reference picture I1 with any one secondary ommatidium image I 1;

Step 2: calculate the cartridge interoceptor mean value, i.e. average at a plurality of CCD sampled values on the same position in the space; Calculate the average of pixel in the local field that centers on a point in the space simultaneously;

Step 3: according to the comparison of cartridge interoceptor average and cartridge average, select suitable syncretizing mechanism, when the brightness average around the cartridge is higher than the mean value of cartridge interior lights receptor, the brightness in the explanation external world is lower so, the information that three photoreceptors need be obtained is by reinforcements that superpose of receptor cell wall, and raising is to the sensitiveness of brightness; Otherwise illustrate that this ambient light degree of illuminating is higher, need so the contrast in field, cartridge place is improved the image that obtains enhancing;

Suppose the ommatidium image I that CCD1 obtains ₁As the reference image; I _k(l) expression k width of cloth image is arranged the brightness of l the pixel in back according to the column vector form; F _Mean(l), L _Mean(l) be the average and reference picture I of photoreceptor brightness in l the cartridge respectively ₁Going up with l cartridge is the mean flow rate of 3 * 3 cartridges at center; Owing to have only three ommatidiums, so the number of the photoreceptor in each cartridge is 3:

$F_{\mathrm{mean}}\left(l\right)=\underset{k=\mathrm{1,2,3}}{\mathrm{mean}}\left(I_k\left(l\right)\right);L_{\mathrm{mean}}\left(l\right)=\underset{k=l-3.l+3}{\mathrm{mean}}\left(L\left(k\right)\right);---\left(1\right)$

Work as F in the formula _Mean(l)＞L _Meam(l) intensity of illumination in the explanation external world is higher the time, adopts first kind of amalgamation mode, otherwise adopts second kind of amalgamation mode; Before merging, image is arranged by the form of column vector;

(1), shunting strengthen be under the normal illumination condition to the same scene position on the fusion treatment of different information; The stimulation that k photoreceptor of l cartridge accepted is I _kWhat (l), k receptor moderate stimulation was the strongest is $I_{\max }\left(l\right)=\underset{k}{\max }\left(I_k\left(l\right)\right),$ Stimulate and the most weak be $I_{\min }\left(l\right)=\underset{k}{\min }\left(I_k\left(l\right)\right),$ Mean flow rate $I_{\mathrm{mean}}\left(l\right)=\underset{k}{\mathrm{mean}}\left(I_k\left(l\right)\right);$ So owing to be stronger illumination condition F _Maen(l)＞L _Mean(l), the therefore extracellular space V of l cartridge _Ecs(l) will receive input, and deduct the electric current of the photoreceptor of the more weak stimulation of the flow direction than the high light receptor; L the voltage V that the induction of cartridge extracellular space produces _Ecs(l):

$V_{\mathrm{ecs}}\left(l\right)=L_{\mathrm{mean}}\left(l\right)+a_1\×(e^{\underset{k=\mathrm{1,2,3}}{\mathrm{\Σ}}(I_{\max }\left(l\right)-I_k\left(l\right))}-e^{\underset{k=\mathrm{1,2,3}}{\mathrm{\Σ}}(I_{\mathrm{mean}}\left(l\right)-I_{\min }\left(l\right))})---\left(2\right)$

A wherein ₁, be parameter, L _Mean(l) be the brightness average of 3 * 3 cartridges on the reference picture that is the center with l cartridge; Here the mediator exponentially that adopts exponential function to discharge when illustrating that brightness is higher increases, and when stimulus of receptor hour, the mediator of release will approach 0, even has backward current and produce;

(2), the stack loop is under the not high situation of intensity of illumination, when the mean value of the monochrome information that receives when receptor is lower than the average of adjacent cartridge, illustrate extraneous brightness low be F _Mean(l)＜L _Mean(l), then open stack loop fusion mode; Here adopt voltage L with adjacent cartridge _Mean(l) with l cartridge internal interface be subjected to brightness value I _kThe absolute value of difference (l) improves the brightness of receptor, so the voltage V of extracellular space _Ecs(l) be:

$V_{\mathrm{ecs}}\left(l\right)=L_{\mathrm{mean}}\left(l\right)+a_2\×\underset{k=\mathrm{1,2,3}}{\mathrm{\Σ}}{e}^{|I_k\left(l\right)-L_{\mathrm{mean}}\left(l\right)|}---\left(3\right)$

The voltage of each ammunition socket joint is L when initial _Mean(l), calculate,, influence V thereby receiver can produce response according to the size that stimulates along with the increase of outside stimulus by formula (1) _Ecs(l); A in formula (2) and (3) ₁, a ₂The coefficient difference, one is the contrast that improves image on the basis of mean flow rate, another one is to increase brightness on the basis of the original brightness of background; Coefficient a ₁, a ₂All be specific conductance, span (0,1] between, a wherein ₁Be the specific conductance between the adjacent receptor (pixel), and a ₂Be the specific conductance between cartridge and the receptor, because the absolute construction of cartridge, its inner electric current flows frequent, and outside when bigger stimulation does not occur, and does not have the flow process of electric current substantially.Therefore can estimate a according to the structure of cartridge ₁＞a ₂Here select a ₁=0.5; a ₂=0.25;

Step 4: under the effect of the inner extracellular voltage of cartridge, obtain the output valve that a cartridge merges at last; The extracellular space voltage V of a cartridge _Ecs(l) meeting is subjected to cartridge extracellular space Z on every side _l-Z _{L '}Influence, so cartridge external space voltage strength is expressed as:

$z_l=V_{\mathrm{ecs}}\left(l\right)+c\×\underset{l-l^{\′}=1}{\mathrm{\Σ}}(L_{\mathrm{mean}}\left(l\right)-L_{\mathrm{mean}}\left(l^{\′}\right))---\left(4\right)$

First V in this formula behind the equal sign _Ecs(l) inherent voltage of expression cartridge interoceptor, second L _Mean(l)-L _MeanThe difference of brightness between l cartridge of (l ') expression and the individual cartridge of l ', the difference of the respective pixel between the promptly adjacent ommatidium image, the size of this difference have influenced the size of cartridge external space voltage; Coefficient c is the coefficient of conductivity of extracellular voltage and cartridge, it also is a kind of specific conductance, span is (0,1] between, l ' has represented other cartridges except that l cartridge, distance between the cartridge has determined the intensity that influences between the cartridge, and obviously along with the increase of distance, influence each other will reduce the impact effect of the cartridge of close together; Here chosen distance cartridge l is that 1 pixel distance is with interior cartridge; But the c conducting is adjacent cartridge, because separate between cartridge and the cartridge in the normal state, cynapse does not connect, but the ion flow of cytoplasm is conducted simultaneously, so therefore specific conductance is less, and c=0.1; According to cartridge external space voltage z _lCalculate the result of l cartridge after having merged several ommatidium images for I ' (l):

I′(l)＝q×z _l+I ₁(l) (5)

Wherein I ' is to have obtained last output result, I after l cartridge merged three receptors (l) ₁(l) be current with reference to ommatidium figure I ₁Last l pixel value; Q is the neuronic cynapse connection weight of cartridge and second order; It is mobile more fast than flooding mechanism that the connection of passing through cynapse like this produces electric current, so the coefficient of conductivity is wanted select q=10 here greatly; After neural fusion treatment finishes I ' is passed through the image that the YUV inverse transformation obtains colored output with colouring information.

The cartridge model is according to a kind of Artificial Neural Network of Moya proposition in 1998.List of references:

[1]Haines?K.G.，Moya?J.A.，Caudell?T.P.Modeling?Nonsynaptic?Communication?BetweenNeurons?in?the?Lamina?Ganglionaris?of?Musca?Domestica[C].1999：

[2]Moya?J.A.A?comprehensive?model?of?the?neuro-ommatidial?layer?m?Musca[D].University?otNew?Mexico，1998.

[3] Haines K.G., Pearlmutter B.A., Moya J.A. waits .Visualizing Communication BetweenNeurons in the Lamina Ganglionaris of Musca domestica[C] .2000:

This neural net is a kind of feedforward network of describing single cartridge inside and cartridge connection on every side thereof.Described from amphiblestroid light receiving unit to the information conduction pattern the high-order neuron LMC cell.This neural net comprises three processing: the coupling between inner six photoreceptors of same cartridge; The ions diffusion of cell colloid and cartridge and the neural LMC cell of second order is connected between cartridge and the cartridge.Receptor receives extraneous brightness to stimulate, and the difference of stimulation has caused producing flowing of electric current between inner six receptors of cartridge.The cartridge volume inside exist can conduction current charged ion, the electromotive force of photoreceptor can carry out the diffusion of electric current by such transmission medium.Cartridge is that a kind of cynapse connects with neuronic connection of second order, and the high-order neuron that environmental stimuli can be delivered to brain goes to handle.This neural net can be regarded the UNE of the single output of a kind of many inputs as; Input has obtained the input of second order nerve cell LMC cell in the time of a plurality of ommatidium image, and this fusion process can be extracted high-frequency information, removes redundant information.

The description of three following these neural nets of formula:

$\frac{\∂p_{k,i}}{\∂t}=-p_{\mathrm{ki}}{A}^{\′}+(B^{\′}-p_{\mathrm{ki}}{C}^{\′})I_{k,i}^{+}+(p_L-2p_{\mathrm{ki}}+p_R)D^{\′}+(Z_k-p_{\mathrm{ki}})E---\left(6\right)$

$\frac{\∂z_k}{\∂t}=-\underset{i}{\mathrm{\Σ}}(p_{k,i}-z_k)E-\underset{l}{\mathrm{\Σ}}(z_k-z_j)L---\left(7\right)$

$\frac{\∂a_{L,i}}{\∂t}=-a_{L,j}F-\underset{i=\mathrm{1,6}}{\mathrm{\Σ}}{G}_i(p_i-z)---\left(8\right)$

A in this model, B, C, D, E, F and G are coefficients.They are respectively:

A＝0.7；B＝1.0；C＝1.0；D＝0.25；E＝0.1；F＝3.0；G＝10.0；L＝30.0。

The principle explanation:

Mostly imaging device and equipment based on the insect compound eye structural is its biological structure characteristics of imitation at present, so that obtain panoramic picture.And the neural processor system of compound eye also only is widely used in target travel detects.About adopting compound eye self adaptive imaging mechanism to be implemented in the imaging device that obtains high quality graphic under the different illumination conditions, do not appear in the newspapers.

In fact, the feature correspondence of the multiple aperture of compound eye a whole set of be different from the nerve regulation mechanism and the syncretizing mechanism of single aperture eye, can be adaptive when illumination condition changes the information fusion mode of adjusting intrinsic nerve unit, make insect obtain clear reliable scene information at different illumination conditions.This visual characteristic of compound eye can be explained with the mechanism that the more individual ommatidium image in the compound eye thin plate layer cartridge merges.Each cartridge is collected is photoreceptor information from different ommatidiums, their correspondences the repeatedly sampled value of a point in the extraneous scene.By the electric coupling relationship together, coupled modes change along with the change of intensity of illumination between the photoreceptor.When illumination condition is more excellent, coupling between the photoreceptor is the process that a kind of contrast stretches, thereby receive than strong stimulation and produce the photoreceptor cell that electric current is diverted to more weak stimulation than the receptor of big electric current, discharge chemical mediator, the balance depolarising of breaking external space ion concentration to extracellular space simultaneously.And extracellular space can be lower than the receptor generation adverse current of external space inherent voltage to aixs cylinder voltage.Realized like this under optimum illumination condition, externally the effect of the equalization of scene stimulation and contrast lifting.When light application ratio was dark, the electric current between the photoreceptor was exactly a kind of mode that superposes and merge.The inherent voltage of extracellular space is lower, is not high enough to the generation backward current, and the electric current of a plurality of photoreceptors improves the intensity of receptor to external space output current by the coupling stack.Extracellular space has been transmitted extraneous stimulus information as a kind of intermediate medium to more higher leveled nerve cell by non-cynapse connection, and the contrast of image and the sensitiveness of brightness are regulated in adaptive brightness according to image background in transmittance process.

As seen compound eye has the treatment mechanism that improves picture quality when merging the ommatidium image, and main characteristics reduces: 1. adopt Local treatment mechanism, need not to calculate, the background luminance by the part feeds back to photoreceptor and controls contrast.The contrast of the image that the electric current shunting between the photoreceptor and the fusion of extracellular space voltage improve automatically, the adaptive electric current amalgamation mode that changes photoreceptor according to local luminance.2. the scope of the variation of the electric current in the cartridge is higher than the brightness excursion far away, and bigger dynamic range can more accurate reflection image information.3. because photoreceptor has lower sensitiveness,, make in the raising of contrast, to have stronger antijamming capability so be not subjected to saturated or The noise.

Of the present invention having the following advantages: thus curved surface multi-charge coupled apparatus group self-adaptive imaging instrument imitation compound eye is adjusted the principle that the nerve conduction mode obtains the self adaptive imaging effect with the change of illumination condition under day alternates with night situation, adopt a plurality of common charge-coupled device (CCD)s and corresponding auxiliary circuit and neural processing algorithm to make up a kind of bionical self-adapting adjustment type imager.Can be according to different illumination conditions, adaptive switching to obtained accurate, distinct image information on the different Image Fusion, broken through traditional low-light (level) camera relatively poor limitation of imaging effect by day, it not only can obtain the image of high-contrast under the normal illumination condition, can also under the weak light condition, obtain the image of high brightness sensitiveness, the monitoring that realized that day alternates with night.The blending algorithm of this imager is simple, and amount of calculation is little, can requirement of real time.

Four, description of drawings

The arrangement mode of accompanying drawing 1:CCD camera;

Accompanying drawing 2: the logic connection layout of circuit of the present invention;

Accompanying drawing 3: flow chart of the present invention;

Accompanying drawing 4: shunting strengthens the module flow process;

Accompanying drawing 5: stack loop module flow process;

Accompanying drawing 6:E2PROM and DSP connection layout;

Five, embodiment

The present invention has designed the multi-charge coupled apparatus group self-adaptive imaging instrument of curved face type optical texture.Main hardware device has 3 common colored CCD cameras, has two DSP digital signal processing chip TMS320DM642 of powerful quick operational capability and TMS320VC5510, programmable vision signal processor SAA7111A and electricity and can wipe storage chip E2PROM.

The model of CCD is 3209A, and this camera has two kinds of standards: Phase Alternation Line system and NTSC, resolution is respectively 500 * 582,510 * 429 two kinds.Adopt pal mode among the present invention, camera lens is of a size of 38mm * 38mm.The resolution of the ommatidium image that obtains is 500 * 582.As shown in Figure 13 CCD are bundled closely, 3 ommatidiums on the curved surface that to be attached to a radius be r in the simulation insect compound eye, the angle between every adjacent two ommatidium optical axises is θ ≈ art sin (D/r).Constitute the curved-surface structure of imitative compound eye.As shown in Figure 3, the o point is the central point of compound eye, and r is the eye radius of compound eye, and D is ommatidium diameter 38mm.

In the dsp chip model: a kind of is TMS320DM642, be aly in the C6000 of the TI company series 32 to be dsp chip at what the multimedia process field was used, its core is a C6416 type high-performance digital signal processor, have extremely strong handling property, the flexibility and the programmability of height, peripheral simultaneously integrated: three configurable video interfaces, can import with video, output or transport stream input seamless link, VCXO interpolation control port (VIC), I ²Equipment and interfaces such as the audio frequency that C bus module etc. are very complete, video and network service are specially adapted to the high-speed dsp application based on digital video/image processing.Another is TMS320VC5510, this chip is 16 high fixed-point dsps of a cost performance of releasing in 2000, adopt advanced correction Harvard structure, 8 buses, CPU are arranged in the sheet, at the sheet memory with at hardware such as sheet peripheral circuits, add the highly command system of specialty, make it have advantages such as power consumption is little, highly-parallel.

Also have video signal preprocessor SAA7111A in addition, this chip is finished the conversion of video formats, and the coloured image of yuv format is provided.Push-up storage (FIFO) IDT72V2113 in addition that cooperates dsp chip to use, its maximum operating frequency is 133MHz; Capacity is 512KB.CPLD (CPLD) LC4128V provides logic control signal for memory and dsp chip.The E2PROM of AT28C256 model is the electricity erasable memorizer of 32k * 8.

The method of attachment of hardware as shown in Figure 2, this curved-surface structure obtains three ommatidium images simultaneously, each CCD colour imagery shot is input to the digital-to-analogue conversion of finishing signal on the vision signal conversion chip SAA7111A by USB interface with analog signal, the amplification of signal and preliminary treatment such as anti-aliasing.SAA7111A output state information and data message, it is last as control signal that state information output is sent to complex programmable logic device (CLPC) LC4128V; Data message is being input on the dsp chip TMS320VC5510 under the CPLC control signal after then cushioning by first in first out storage chip (FIFO) IDT72V2113.

Three TMS320VC5510 chips are finished the chrominance information of three way word color picture signals and the separating treatment of monochrome information respectively.According to the characteristics of only luminance component being handled in the visual processes, three dsp chip TMS320VC5510 go up the Y component are extracted respectively, are input on the next stage TMS320CM642 type dsp chip and carry out fusion treatment, and be left intact after the color difference components input.

TMS320VC5510 chip and next stage dsp chip TMS320DM642 are the annexations of master-slave mode, and three TMS320VC5510 are from sheet, and TMS320DM642 is as main leaf.Main leaf adopts interrupt mode that three dateouts from sheet are read.Each TMS320VC5510 from sheet all to main leaf input data information and state information.What broad arrow was represented is data message, the state information of thin arrow representative output.State information is the interrupt signal of sending to main leaf from sheet DSP, and the procedure turn of interrupting the master chip operation is read from the data of chip output.Finish neural fusion treatment on the main leaf TMS320DM642 and the monochrome information of colour information after fusion treatment obtained colored output image by the YUV inverse transformation.

Fig. 3 is the flow chart of this patent.Mainly contain three big modules: acquisition module, pretreatment module, Fusion Module.

Acquisition module cooperates the vision signal conversion chip to realize respectively by three CCD.The CCD camera of 3 same physical parameter is arranged arrangement according to the curved surface of imitative compound eye structural.The image that each CCD camera obtains is a width of cloth ommatidium image, and each pixel in the ommatidium image is a photoreceptor in the ommatidium, and the resolution of the CCD of Xuan Zeing is 500 * 582 here.

Pretreatment module is respectively the monochrome information of the digital picture that obtains separately to be separated with colour difference information by three dsp chips.The monochrome information of separating and chrominance information are transferred to next stage respectively by data wire main dsp chip.This module guarantees importing into synchronously of three width of cloth ommatidium images that synchronization is taken also under the control of CPLC.

Fusion Module is the core of this patent, and the TMS320DM642 core is realized on main leaf, and this master chip has also connected two E2PROM storage chip AT28C256, is used for storing data and program.This module receives from monochrome information and chrominance information after three dsp chips processing, only monochrome information is carried out registration, finds locational three sample values of respective pixel in three ommatidiums that will enter same cartridge.A pixel on the corresponding fused images of each cartridge.Because the angle between the known image in design process can pass through direct registration three width of cloth images of affine transformation.Select any pair to be reference picture, other two width of cloth are registrated on this reference picture.The formula of affine transformation:

$\left(\begin{array}{c}x\\ y\end{array}\right)=\left(\begin{array}{cc}{a}_{11}& a_{12}\\ a_{21}& a_{22}\end{array}\right)\left(\begin{array}{c}{x}^{\&prime;}\\ y^{\&prime;}\end{array}\right)+\left(\begin{array}{c}{b}_1\\ {\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="H2009102641659E00031.png"\; state="\{\{state\}\}">b</figure-callout>}}_2\end{array}\right)$

Wherein: element representation rotation and zoom factor in the A matrix, b vector representation shift factor.Here select I ₁As the reference image, adopt two matrix A ₁, A ₂I is described ₂, I ₃With respect to I ₁Twiddle factor.The cartridge structure need not judged illumination condition on the overall situation, but decides which kind of amalgamation mode of employing by the analysis of part.First kind of amalgamation mode is that shunting strengthens, and another kind of amalgamation mode is the stack loop.

When ambient light degree of illuminating is higher, current imbalance between three photoreceptors, can produce coupling phenomenon between the adjacent in twos receptor, stimulate bigger receptor will shunt a part to stimulating less receptor, the voltage of the relative extracellular space of receptor that each acceptance simultaneously stimulates is higher, and the release that produces chemical mediator at the aixs cylinder position realizes depolarising.If the stimulation that certain receptor is accepted is very little, the voltage of generation is far smaller than the inherent voltage of extracellular space, will produce backward current so.When therefore having sudden change brightness in stimulation, different information flows between a plurality of photoreceptors, has shared the phenomenon that single receptor is accepted the big electric current of undue intense stimulus generation.Such shunting simultaneously makes the contrast of image improve automatically.Shown in the accompanying drawing 4, each photoreceptor node is all told certain electric current to two adjacent receptors, photoperceptive output that the difference between three environmental stimulis is corresponding, thus produced the induced current of extracellular space.Such coupling mechanism just shows a kind of inhibition of sudden change brightness.

Opposite lower when extraneous brightness, the brightness that the receptor of cartridge inside receives superposes between the receptor to increase the sensitiveness to light because extraneous brightness low two causes difference hour.As shown in Figure 5, information circulation between three nodes is strengthened, and the induced current of extracellular space is that the difference of environmental stimuli and external space average voltage intensity produces.

The hardware connection layout has shown the connected mode of storage chip E2PROM and dsp chip as shown in Figure 6 among Fig. 7, deposited the program and the data of main leaf operation in this dsp chip.The CEn end of dsp chip is connected by a not gate with the section of the enabling CE end of E2PROM, and low level is effective.Output enable end AOE end links to each other by a not gate with the OE end, and low level is effective.The Enable Pin AWE that writes of DSP links to each other by a not gate with the WE end of storage chip.The address is by EA _XXOutput to the A[15...0 of storage chip] on the end, data terminal ED[15...0] link to each other with the input/output port of storage chip.

The present invention copies the mechanism of compound eye adaptive adjusting amalgamation mode with the change of illumination condition, by the auxiliary multi-charge coupled apparatus group self-adaptive imaging instrument of having realized of common imaging device and many dsp chips group and some storage chips and logic control chip, realize obtaining of round-the-clock high quality graphic.There is overlapping image in three width of cloth that adopt three common CCD cameras that are fixed on the arch face to obtain Same Scene.These superimposed images carry out convergence analysis on chip TMS320DM642, provide the illumination condition discrimination formula according to present image information, select suitable amalgamation mode to obtain last output at last.

Advantage of the present invention: the shortcoming of traditional low-light-level imaging instrument high cost and complexity has been avoided in this invention design, the analysis principle that takes full advantage of the biological vision Simple fast cooperates flexibly nerve conduction mechanism simultaneously, rely on the combination of DSP and fpga chip to come fast, dexterous replacement PC has been realized bionical neural fusion treatment, the adaptive scene image that obtains, because algorithm is simple, requirement of real time, and have the advantage such as popularization of being easy to.

Claims (2)

1. the multi-charge coupled apparatus group self-adaptive imaging instrument of a curved surface optical texture is characterized in that:

Comprise 3 identical CCD cameras, 3 are used for first kind DSP digital signal processing chip that luminance component separates with two color difference components, 1 and are used to finish the second class DSP digital signal processing chip, 3 programmable vision signal processing chips that are used for analog-to-digital conversion and system conversion, 3 electricity that multiple image merges and can wipe storage chip;

Above-mentioned 3 CCD closely link together, and being attached to a radius is on the curved surface of r, and the angle between adjacent two ommatidium optical axises is the curved-surface structure that θ ≈ art sin (D/r) constitutes imitative compound eye, and wherein r is the eye radius of compound eye, and D is the ommatidium diameter;

Above-mentioned 3 CCD cameras carry out preliminary treatment by the input end of analog signal that USB interface is connected to above-mentioned 3 programmable vision signal processing chips respectively; The state information of programmable vision signal processing chip is exported in the complex programmable logic device (CLPC) as control signal, data-signal then can be wiped storage chip through above-mentioned 3 electricity and be input to respectively in above-mentioned 3 first kind DSP digital signal processor core, and the control signal of 3 first kind DSP digital signal processing chips is input to 1 second class DSP digital signal processing chip as chip selection signal and enable signal.

2. utilize the self adaptive imaging method of the multi-charge coupled apparatus group self-adaptive imaging instrument realization of the described curved surface optical texture of claim 1, it is characterized in that may further comprise the steps:

(1), utilize the ommatidiums independent imagings respectively in three CCD cameras simulation compound eye, obtain three width of cloth ommatidium images;

(2), utilize the programmable vision signal processing chip respectively three secondary ommatidium images processes to be carried out the conversion of analog-to-digital conversion and standard;

(3), utilize three first kind DSP digital signal processing chips that three width of cloth ommatidium images are carried out separating of luminance component and two color difference components respectively;

(4), according to the characteristics of only luminance component being handled in the visual processes, extract the Y component of three secondary ommatidium images, together with the color difference components of not doing any processing after separating, be input to the multiple image fusion treatment that inspired by the biological compound eye cartridge jointly, concrete blending algorithm is as follows:

Step 1: establish I1, I2 and I3 and represent three secondary ommatidium images respectively, extract the luminance component of three width of cloth ommatidium images; , as with reference to image I2 and I3 are registrated on the reference picture I1 with any one secondary ommatidium image I 1;

Step 2: calculate the cartridge interoceptor mean value, i.e. average at a plurality of CCD sampled values on the same position in the space; Calculate the average of pixel in the local field that centers on a point in the space simultaneously;

Step 3: according to the comparison of cartridge interoceptor average and cartridge average, select suitable syncretizing mechanism, when the brightness average around the cartridge is higher than the mean value of cartridge interior lights receptor, the brightness in the explanation external world is lower so, the information that three photoreceptors need be obtained is by reinforcements that superpose of receptor cell wall, and raising is to the sensitiveness of brightness; Otherwise illustrate that this ambient light degree of illuminating is higher, need so the contrast in field, cartridge place is improved the image that obtains enhancing;

Suppose the ommatidium image I that CCD1 obtains ₁As the reference image; I _k(l) expression k width of cloth image is arranged the brightness of l the pixel in back according to the column vector form; F _Mean(l), L _Mean(l) be the average and reference picture I of photoreceptor brightness in l the cartridge respectively ₁Going up with l cartridge is the mean flow rate of 3 * 3 cartridges at center; Owing to have only three ommatidiums, so the number of the photoreceptor in each cartridge is 3:

$F_{\mathrm{mean}}\left(l\right)=\underset{k=1,\mathrm{2,3}}{\mathrm{mean}}\left(I_k\left(l\right)\right);L_{\mathrm{mean}}\left(l\right)=\underset{k=l-3,l+3}{\mathrm{mean}}\left(L\left(k\right)\right);---\left(1\right)$

Work as F in the formula _Mean(l)＞L _Mean(l) intensity of illumination in the explanation external world is higher the time, adopts first kind of amalgamation mode, otherwise adopts second kind of amalgamation mode; Before merging, image is arranged by the form of column vector;

(1), shunting strengthen be under the normal illumination condition to the same scene position on the fusion treatment of different information; The stimulation that k photoreceptor of l cartridge accepted is I _kWhat (l), k receptor moderate stimulation was the strongest is $I_{\max }\left(l\right)=\underset{k}{\max }\left(I_k\left(l\right)\right),$ Stimulate and the most weak be $I_{\min }\left(l\right)=\underset{k}{\min }\left(I_k\left(l\right)\right),$ Mean flow rate $I_{\mathrm{mean}}\left(l\right)=\underset{k}{\mathrm{mean}}\left(I_k\left(l\right)\right);$ So owing to be stronger illumination condition F _Mean(l)＞L _{Mean (}L), the therefore extracellular space V of l cartridge _Ecs(l) will receive input, and deduct the electric current of the photoreceptor of the more weak stimulation of the flow direction than the high light receptor; The voltage of l cartridge extracellular space induction generation is V _Ecs(l):

$V_{\mathrm{ecs}}\left(l\right)=L_{\mathrm{mean}}\left(l\right)+a_1\&times;({e^{\underset{k=\mathrm{1,2,3}}{\mathrm{\&Sigma;}}}}^{(I_{\mathrm{mas}}\left(l\right)-I_k\left(l\right))}-e^{\underset{k=\mathrm{1,2,3},}{\mathrm{\&Sigma;}}(I_{\mathrm{mean}}\left(l\right)-I_{\min }\left(l\right))})---\left(2\right)$

A wherein ₁, be parameter, L _Mean(l) be the brightness average of 3 * 3 cartridges on the reference picture that is the center with l cartridge; Here the mediator exponentially that adopts exponential function to discharge when illustrating that brightness is higher increases, and when stimulus of receptor hour, the mediator of release will approach 0, even has backward current and produce;

(2), the stack loop is under the not high situation of intensity of illumination, when the mean value of the monochrome information that receives when receptor is lower than the average of adjacent cartridge, illustrate extraneous brightness low be F _Mean(l)＜L _Mean(l), then open stack loop fusion mode; Here adopt voltage L with adjacent cartridge _Mean(l) with l cartridge internal interface be subjected to brightness value I _kThe absolute value of difference (l) improves the brightness of receptor, so the voltage V of extracellular space _Ecs(l) be:

$V_{\mathrm{ecs}}\left(l\right)=L_{\mathrm{mean}}\left(l\right)+a_2\&times;\underset{k=1,2,3}{\mathrm{\&Sigma;}}{e}^{|I_k\left(l\right)-L_{\mathrm{mean}}\left(l\right)|}---\left(3\right)$

The voltage of each ammunition socket joint is L when initial _Mean(l), calculate,, influence v thereby receiver can produce response according to the size that stimulates along with the increase of outside stimulus by formula (1) _Ecs(l); A in formula (2) and (3) ₁, a ₂The coefficient difference, one is the contrast that improves image on the basis of mean flow rate, another one is to increase brightness on the basis of the original brightness of background; Coefficient a ₁, a ₂All be specific conductance, span (0,1] between, a wherein ₁Be the specific conductance between the adjacent receptor (pixel), and a ₂Be the specific conductance between cartridge and the receptor, because the absolute construction of cartridge, its inner electric current flows frequent, and outside when bigger stimulation does not occur, and does not have the flow process of electric current substantially.Therefore can estimate a according to the structure of cartridge ₁＞a ₂Here select a ₁=0.5; a ₂=0.25;

Step 4: under the effect of the inner extracellular voltage of cartridge, obtain the output valve that a cartridge merges at last; The extracellular space voltage v of a cartridge _Ecs(l) meeting is subjected to cartridge extracellular space z on every side _l-z _rInfluence, so cartridge external space voltage strength is expressed as:

$z_l=V_{\mathrm{ecs}}\left(l\right)+c\&times;\underset{l-l^{\&prime;}=1}{\mathrm{\&Sigma;}}(L_{\mathrm{mean}}\left(l\right)-L_{\mathrm{mean}}\left(l^{\&prime;}\right))---\left(4\right)$

First v in this formula behind the equal sign _Ecs(l) inherent voltage of expression cartridge interoceptor, second L _Mean(l)-L _MeanThe difference of brightness between l cartridge of (l ') expression and the individual cartridge of l ', the difference of the respective pixel between the promptly adjacent ommatidium image, the size of this difference have influenced the size of cartridge external space voltage; Coefficient c is the coefficient of conductivity of extracellular voltage and cartridge, it also is a kind of specific conductance, span is (0,1] between, l ' has represented other cartridges except that l cartridge, distance between the cartridge has determined the intensity that influences between the cartridge, and obviously along with the increase of distance, influence each other will reduce the impact effect of the cartridge of close together; Here chosen distance cartridge l is that 1 pixel distance is with interior cartridge; But the c conducting is adjacent cartridge, because separate between cartridge and the cartridge in the normal state, cynapse does not connect, but the ion flow of cytoplasm is conducted simultaneously, so therefore specific conductance is less, and c=0.1;

According to cartridge external space voltage z _lCalculate the result of l cartridge after having merged several ommatidium images for I ' (l):

I′(l)＝q×z _l+I ₁(l) (5)

Wherein I ' is to have obtained last output result, I after l cartridge merged three receptors (l) ₁(l) be current with reference to ommatidium figure I ₁Last l pixel value; Q is the neuronic cynapse connection weight of cartridge and second order; It is mobile more fast than flooding mechanism that the connection of passing through cynapse like this produces electric current, so the coefficient of conductivity is wanted select q=10 here greatly; After neural fusion treatment finishes I ' is passed through the image that the YUV inverse transformation obtains colored output with colouring information.

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