CN1984259A

CN1984259A - Automatic real-time frame by frame continuous adjuster of shutter for camera

Info

Publication number: CN1984259A
Application number: CN 200510022304
Authority: CN
Inventors: 袁学东
Original assignee: Sichuan University; Sichuan Chuanda Zhisheng Software Co Ltd
Current assignee: Sichuan University; Sichuan Chuanda Zhisheng Software Co Ltd
Priority date: 2005-12-15
Filing date: 2005-12-15
Publication date: 2007-06-20
Anticipated expiration: 2025-12-15
Also published as: CN100474896C

Abstract

The invention features the following: the 14 and 15 pins of MCU are connected to the 9 and 7 pins of bus driving circuit; the 16, 17, 18 and 19 pins of MCU are connected to the 8.6.4 and 2 pins of bus driving circuit; the 11 and 12 of MCU are connected to the 1 and 2 pins of character superimpose; in the MCU, there is a control unit. The control unit makes the flowing selection: at standby state, the MCU detects the trigger signal; when there is a trigger signal, firstly decides if there is a synchronizing signal occurring; if not, continues to wait; when the synchronizing signal comes, according to the preset, continues to change the shutter frame numbers and the shutter value of each frame of image; outputs the shutter value firstly changed; controls the character superimposer to superimpose the shutter value changed with image frame on the video, and makes the decision for the shutter value of next frame until completing the preset times.

Description

Automatic real-time frame by frame continuous adjuster of shutter for camera

One, technical field

The invention belongs to the transmission and the processing of digital information, be specifically related to the self-regulating device of a kind of video camera successive frame shutter in video images such as intelligent transportation, video monitoring processing application.

Two, background technology

In video images such as intelligent transportation, video monitoring processing application, require to obtain motion video image, can run into many difficulties during particularly outdoor all-weather real-time video acquisition, the strong variations of available light for example, light is from the daytime to the night, variation difference from the summer to the winter, the and for example influence of the reflective high light of sunlight direct projection at noon cement pavement, night, automobile was opened travelling of headlight or the like suddenly; And the auto iris adjustable range of general rig camera is limited, after shutter is manually set, be difficult to take into account the high-speed moving object requirement high-speed shutter and night the exposure deficiency contradiction.Though some rig camera provides serial line interface in the prior art, can change shutter speed, but serial line interface since the restriction of baud rate (with 9600 baud rates, start bit, 8 bit data positions, a byte of a position of rest transmission need 1ms approximately,) speed is slow, and owing to do not know when video camera begins the collection of a two field picture, the control end camera shutter of having no idea to realize changing frame by frame; But in actual applications, sometimes need to obtain the image of the different exposure values of high-speed moving object, the high speed object is owing to there is the motion hangover, for present interlacing scan video camera, the rear end image identification system can only adopt single game (strange or idol field) image, this just requires video camera to change shutter frame by frame, and the method for prior art obviously is unconformable.

Three, summary of the invention

Purpose of the present invention with regard to provide a kind of by preset value in real time, continuously the time for exposure of the every two field picture of video camera is regulated, obtain the automatic real-time frame by frame continuous adjuster of shutter for camera of the consecutive image frame by frame of moving object difference exposure values, can not realize frame by frame the difficulty of adjusting continuously to solve the existing camera shutter method (manual adjustments, serial line interface are regulated or automatic gate) of regulating.

Can realize above-mentioned purpose by the following technical solutions: a kind of automatic real-time frame by frame continuous adjuster of shutter for camera, mainly comprise the sync separator circuit U3 that connects the external camera device and the composite video signal of input is separated, and the pulsewidth adjustment that is attached thereto, delay circuit U6, U7, the MCU microcontroller U1 that the synchronizing signal that separate to obtain is controlled, the bus driving circuits U8 that links to each other with MCU microcontroller U1, character adder U2 and input and output socket JP that the composite video signal that video camera is imported is marked, 14 pin that it is characterized in that MCU microcontroller U1,9 pin of 15 pin and bus driving circuits U8,7 pin connect, the 16th of MCU microcontroller U1,17,18, the 8th of 19 pin and bus driver U8,6,4,2 pin connect, 11 of MCU microcontroller U1,1 of 12 pin and character adder spare U2,2 pin connect; Establish control device in the MCU microcontroller U1, this device can be selected following action: under holding state, MCU microcontroller U1 detects triggering signal always, when triggering signal, MCU microcontroller U1 differentiates at first whether synchronizing signal occurs, wait for as then not continuing, when synchronizing signal arrives, according to the predefined shutter value that continuously changes frame number and every two field picture of shutter, the shutter value that instruction output changes for the first time, control character stack device U2 overlaying character on video shows the shutter value that this two field picture changes simultaneously.After finishing two field picture shutter change, carry out the differentiation that the subsequent frame shutter changes immediately, up to finishing predetermined times;

After its feature is that also sync separator circuit U3 is the shaping and logical process of isolated synchronizing signal from video through U6A among pulsewidth adjustment, delay circuit U6, the U7, be input to the 2nd pin of the two one-shot multivibrator U7A that have the Schmidt trigger input, regulate its external timing element C _ExtAnd R _ExtValue, change output pulse width, obtain delayed sync signal; Separate the 12nd pin, the 13rd pin that the composite synchronizing signal (COMPOSITE SYNC) that obtains is received U6A among pulsewidth adjustment, delay circuit U6, the U7 through pulsewidth adjustment, delay circuit U6, U7, after shaping, be input to the 17th pin of character adder U2, as the synchronizing signal of character stack; MCU microcontroller U1 is from the 16th, 17,18,19 pin output control camera shutter signal, through bus driving circuits U8 the 12nd, 14,, 16,18 pin output control signal is connected with the 5th, 6,7,8 pin of input and output socket JP, can be connected on the S terminal of video camera by a S terminal line, camera shutter is regulated;

Its feature is that also the moving-target that is provided by the exterior vehicle detector detects triggering signal, receive the 3rd pin, the 4th pin of input and output socket JP, be input to the 11st pin of bus driver U8 again, after driving, isolating, send 14 pin of MCU microcontroller U1, after MCU microcontroller U1 monitors this signal, regulate camera shutter according to the synchronizing signal that obtains simultaneously, the control character stack; Also be input to simultaneously the 24th pin of character adder U2 by the vision signal of video camera input, as vehicle through out-of-date, when MCU microcontroller U1 regulates camera shutter, can carry out the character stack to the vision signal of video camera output by control character superimposer U2,21 pin by character adder U2 output to J2, and rear end equipment can be accepted vision signal by this output interface.

Need to prove predetermined frame number, refer to the frame number that the adjuster setting can be regulated the video image shutter continuously, such as regulating 3 frames continuously; Predetermined shutter value referred to and sets the shutter value of regulating each frame in 3 frames, such as 1/1000,1/2000,1/4000 second.These set points in use can be changed.

Technical scheme disclosed by the invention shows by the good effect that test produces, the one, in some life outdoor videos system such as automobile high-speed road charge station, traffic intelligent control system, solved monitoring camera fixedly the shutter value can not take into account the strong illumination on daytime, practical problems such as under-exposure at night have broad practice to be worth; The 2nd, automatic real-time frame by frame continuous adjuster of shutter for camera has solved in the past in the Video Applications can not be continuously, this difficulty of a value that accelerates frame by frame, and particularly existing monitoring camera does not generally provide frame by frame, the real time altering shutter; Utilize adjuster of the present invention can make the monitoring camera tool increase this function, more satisfactory solution the life outdoor videos system need to regulate camera shutter method (manual adjustments, serial line interface are regulated or automatic gate) because the light excursion is big and can not realize the problem of regulating continuously frame by frame.

Four, description of drawings

Fig. 1 is an automatic real-time frame by frame continuous adjuster of shutter for camera structural representation block diagram of the present invention

Fig. 2 is the said frame by frame continuous adjuster sync separator circuit of a present invention schematic diagram

Fig. 3 is that the said adjuster triggering signal of the present invention detects and shutter regulating circuit schematic diagram

Fig. 4 is the said frame by frame continuous adjuster video image mark of the present invention circuit theory diagrams

Fig. 5 is the said frame by frame continuous adjuster control device of a present invention flow chart

Fig. 6 is an automatic real-time frame by frame continuous adjuster of shutter for camera socket JP schematic diagram of the present invention

Fig. 7 is the transformation video camera hand switch structure line schematic diagram of the said adjuster of the present invention

Fig. 8 is an automatic real-time frame by frame continuous adjuster of shutter for camera workflow schematic diagram of the present invention

Five, embodiment

Be described in further detail and provide embodiment and application process in conjunction with the accompanying drawings.

From Fig. 1 Fig. 2 Fig. 3 Fig. 4 as can be seen, realize the said purpose of the present invention, at first to from the video camera composite video signal, extract frame, field sync signal by sync separator circuit U3, present embodiment has selected for use the LM1881 chip to handle, but the frame of composite video signal, field sync signal indication is the beginning of frame, a vision signal, changing the electronic shutter value if directly desynchronize as synchronizing signal, is to reach the purpose that changes this two field picture shutter.Therefore this has increased the adjustment of synchronizing signal pulsewidth, delay circuit U6, U7 after the synchronizing signal of LM1881 chip output, this circuit has been selected 74HC00,74LS221 chip for use, handle as pulsewidth adjustment, delay to the synchronizing signal after separating, this processing is very important.After making the frame synchronizing signal delay certain hour of present frame, as the synchronizing signal that changes next frame image exposuring time (shutter value).Can certainly manage from video camera sequencing control, CCD chip for driving (CXD2480), to obtain clock signal, video camera be changed bigger, be difficult in the actual project installation and use but do like this.The present invention has taked the most direct a kind of easy easy-to-install design, the analog video of video camera output is input in the said adjuster of the present invention by video input interface J3, through being input to the 2nd pin (PIN2) of the LM1881 chip of sync separator circuit U3 after impedance matching resistance R 1, R2 and the capacitor C 33; The LM1881 chip is isolated synchronizing signal (COMPOSITE SYNC, VERTICALSYNC, ODD/EVEN FIELD PULSE composite sync, synchronous, the parity field pulse of row) from composite video.

Line synchronizing signal (VERTICAL SYNC) is received the 1st pin, the 2nd pin of the 74HC00 chip of U6A among delay circuit U6, the U7 of U6, and be input to the 4th pin of same chip U6B after shaping: parity field pulse signal (ODD/EVENFIELD PULSE) is received 74HC00 chip the 5th pin of U6B; After line synchronizing signal (VERTICAL SYNC) and parity field pulse signal (ODD/EVEN FIELD PULSE) the shaping and logical process through 74HC00 chip (NAND gate), be input to the 2nd pin of two one-shot multivibrator U7A of band application schmitt trigger input among the adjustment of synchronizing signal pulsewidth, delay circuit U6, the U7, present embodiment U7A selects the 74LS221 chip for use, regulates the external timing element C of 74LS221 chip _Ext(C7_2) and R _Ext(R7_2) value just can change output pulse width tw=t _w=C _ExtR _TLn2 reaches the purpose of adjustment, delayed sync signal.Signal through pulse-width regulated is exported from 74LS221 chip the 4th pin of U7A, receives the 10th pin of same chip U7B, after handling through second module 74LS221 chip with identical function U7B, exports the synchronizing signal of control video camera through the 5th pin of U7B again.This synchronizing signal is input to the 13rd pin of bus driver U8, and what present embodiment U8 selected for use is the 74HC244 chip, is outputed to the 15th pin of MCU microcontroller U1 after driving by the 7th pin.Whether MCU microcontroller U1 differentiates according to this synchronizing signal can the adjusted in concert camera shutter.The synchronizing signal of delay circuit U7 output is connected on 15 pins of MCU microcontroller U1 through 7 pin of bus driver U8.

General rig camera is encoded the back with the analog form output video through PAL, change shutter for which two field picture beginning rear end Video processing software can be known from according to the predetermined value of establishing, must be marked on analog video, the present invention has used character adder U2 commonly used to come the composite video signal of described video camera input is marked.U2 has selected for use the NEC6464 chip to finish the function of character stack in the present embodiment.The composite synchronizing signal of separating through the LM1881 of U3 chip from the composite video signal of video camera output (COMPOSITESYNC) is received the 12nd pin, the 13rd pin of the 74HC00 chip of U6D, after shaping, be input to 17 pin of the NEC6464 chip of character adder U2, as the synchronizing signal of character stack.When MCU microcontroller U1 has monitored moving object through out-of-date, when instruction changes shutter, the NEC6464 chip overlaying character of meeting control character superimposer U2.

In conjunction with Fig. 1 Fig. 5, it is the design of the system core that present embodiment has adopted high performance microcontroller and logical device, be that MCU microcontroller U1 has selected high performance AT89C2051 chip for use, established control device in its PEROM (programmable and erasable read only memory), this device can be selected following action: under holding state, the control device of MCU microcontroller U1 detects the moving object detection triggering signal always, judged whether that moving target occurs, do not continued again to detect if return; If the moving object detection triggering signal is arranged, whether MCU microcontroller U1 at first detects and differentiates the video camera synchronizing signal and occur, if not then continue to wait for; If have then according to the predefined shutter value that continuously changes frame number and every two field picture of shutter, the shutter value that instruction output changes for the first time, control character superimposer U2 overlaying character on video shows the shutter value that this two field picture changes simultaneously.Do you judge that simultaneously camera shutter reaches predetermined frame number? if do not return continuation, after reaching predetermined frame number, recover the conventional shutter setting of video camera.After finishing two field picture shutter change, carry out the differentiation that the subsequent frame shutter changes immediately, up to finishing predetermined times.

In order to obtain the moving-target triggering signal, so that with camera frame and field sync signal coupling, under MCU microcontroller U1 control, directly regulate camera shutter speed, present embodiment has adopted dynamic coil circuit to detect and drive circuit U8, MCU microcontroller U1 connects, dynamic coil circuit detects output moving-target triggering signal through 3 of input and output socket JP, 4 pin, receive through 9 pin of bus driver U8 on 14 pins of MCU microcontroller U1, simultaneously the vision signal of importing this adjuster through J3 also is input to the 24th pin of the NEC6464 of U2, as vehicle through out-of-date, when MCU microcontroller U1 regulates camera shutter, the NEC6464 chip of command character superimposer U2 carries out the character stack to the vision signal of video camera output, output to the output interface J2 of this adjuster through the NEC6464 of U2 chip the 21st pin, rear end equipment can be accepted vision signal by this output interface.

Be connected with the 5th, 6,7,8 pin of input and output socket JP through the 12nd, 14,16, the 18 pin output control signal of bus driving circuits U8 as can be seen in conjunction with Fig. 6 Fig. 7, and be connected on the S terminal of video camera by a S terminal line, camera shutter is regulated; And the S terminal of video camera is transformed easily, promptly adopts the hard mode that links, and directly the manual toggle switch of video camera place is transformed the illustrative method that Fig. 7 provides manual toggle switch place to advance to transform.Monitoring camera generally all has the toggle switch of manual change shutter, and the present embodiment control line that the toggle switch of manual shutter is original extracts, and forms a S terminal line, has finished the shutter control connection to video camera.Satisfying after the above-mentioned condition the present invention fully can be automatically, continuously change, regulate shutter in real time.Accompanying drawing 8 is embodiment of practice of the present invention, and used one group of shutter value is 1/,500,1/1,000 1/4,000 1/5000 seconds in process of the test; When vehicle when the tunnel face is rolled away from, on the occasion of noon in midsummer sunlight very strong, traditional monitoring camera is followed vehicle snapshot, it is excessive that its result captures the photo lithography that gets off.Adopt that to improve the shutter value suddenly in the centre of one group of shutter value behind the adjuster of the present invention be 1/1000,1/4000 second, make strong illumination reduce to minimum, use this group photo of regulating the shutter value frame by frame continuously that changes to obtain the license plate number that can meet the demands the influence of vehicle license.

Claims

1, a kind of automatic real-time frame by frame continuous adjuster of shutter for camera, mainly comprise the sync separator circuit [U3] that connects the external camera device and the composite video signal of input is separated, and the pulsewidth adjustment that is attached thereto, delay circuit [U6, U7], the MCU microcontroller [U1] that the synchronizing signal that separate to obtain is controlled, the bus driving circuits [U8] that links to each other with MCU microcontroller [U1], character adder [U2] and input and output socket [JP] that the composite video signal that described video camera is imported is marked, 14 pin that it is characterized in that MCU microcontroller [U1], 9 pin of 15 pin and bus driving circuits [U8], 7 pin connect, the 16th of MCU microcontroller [U1], 17,18, the 8th of 19 pin and bus driver [U8], 6,4,2 pin connect, 11 of MCU microcontroller [U1], 1 of 12 pin and character adder [U2], 2 pin connect; Establish control device in the MCU microcontroller [U1], this device can be selected following action: under holding state, MCU microcontroller [U1] detects triggering signal always, when triggering signal, MCU microcontroller [U1] differentiates at first whether synchronizing signal occurs, wait for as then not continuing, when synchronizing signal arrives, according to the predefined shutter value that continuously changes frame number and every two field picture of shutter, the shutter value that instruction output changes for the first time, control character stack device [U2] overlaying character on video shows the shutter value that this two field picture changes simultaneously; After finishing two field picture shutter change, carry out the differentiation selection that the subsequent frame shutter changes immediately, up to finishing predetermined times.

2, frame by frame continuous adjuster according to claim 1, after it is characterized in that sync separator circuit [U3] makes the shaping and logical process of [U6A] circuit in the adjustment of isolated synchronizing signal process pulsewidth, the delay circuit [U6, U7] from composite video, be input to the 2nd pin of the two one-shot multivibrators [U7A] that have the Schmidt trigger input, regulate its external timing element Cext and the value of Rext, can change output pulse width, obtain delayed sync signal;

3, frame by frame continuous adjuster according to claim 1, it is characterized in that separating the 12nd pin, the 13rd pin that the composite synchronizing signal (COMPOSITE SYNC) that obtains is received [U6D] in pulsewidth adjustment, the delay circuit [U6, U7] through sync separator circuit [U3], after shaping, be input to the 17th pin of character adder [U2], as the synchronizing signal of character stack;

4, frame by frame continuous adjuster according to claim 1, it is characterized in that MCU microcontroller [U1] is from the 16th, 17,18,19 pin output control camera shutter signal, the 12nd, 14,16,18 pin output control signal through bus driving circuits [U8] is connected with the 5th, 6,7,8 pin of input and output socket [JP], can be connected on the S terminal of video camera by a S terminal line, camera shutter is regulated;

5, frame by frame continuous adjuster according to claim 1, the moving-target detection signal that provides by the exterior vehicle detector is provided, receive the 3rd pin, the 4th pin of input and output socket [JP], be input to the 11st pin of bus driver [U8] again, after driving, isolating, send 14 pin of MCU microcontroller [U1], after MCU microcontroller [U1] monitors this signal, regulate camera shutter according to the synchronizing signal that obtains simultaneously, the control character stack;

6, frame by frame continuous adjuster according to claim 1, it is characterized in that the vision signal of importing also is input to the 24th pin of character adder [U2] simultaneously, as vehicle through out-of-date, when MCU microcontroller [U1] is regulated camera shutter, can the control character superimposer [U2] vision signal of video camera output is carried out the character stack and 21 pin by [U2] output to output interface [J2], rear end equipment can be accepted vision signal by this output interface.