JP3195418B2 - Image information recording / reproducing system, image information recording device, and image information reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information recording / reproducing system, an image information recording apparatus, and an image information reproducing apparatus.
It is particularly effective for special reproduction output such as a video printer.

[0002]

2. Description of the Related Art FIG. 1 shows a configuration example of a conventional general video printer.

In FIG. 1, an image pickup signal from a video camera 10 or a reproduced video signal from a VTR (video tape recorder) is converted into an analog signal by a video printer 1.
1 is supplied. Further, a moving image based on the supplied analog signal can be monitored by the display 12. On the other hand, A / D in the video printer 11
The above analog signal is converted into a digital signal by the (analog / digital) converter 110, and the operation key (KE
Y) At the timing specified by 116, the digital signal is stored in the field memory 111 with one desired screen as a still image. This field memory 111
The storage screen inside is displayed on the display 12 by switching the switch 115 by operating the operation key 116, and can be arbitrarily checked. The information stored in the field memory 111 is supplied to the printing unit 114 to perform a printout (printing) process.

[0004]

However, in the conventional image information recording / reproducing system or image processing apparatus as described above, the image pickup or the image processing is performed only in a relatively narrow range as compared with the gradation range which the subject originally has. There was a problem to be solved, such as the inability to record.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to use an imaging and recording system which can perform imaging or recording only in a relatively narrow range as compared with the gradation range of an object. It is another object of the present invention to provide an image information recording / reproducing system, an image information recording device, and an image information reproducing device capable of reproducing an image signal having a gradation range equivalent to the gradation expression of a subject.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a subject is imaged at an optimum exposure value by automatic exposure control, and the optimum exposure value is calculated. Imaging means for imaging even an exposure value increased or decreased by a predetermined amount, and shift information indicating a shift amount and a shift direction with respect to an optimum exposure value are added to each of a plurality of imaging signals imaged by changing the exposure value by the imaging means Recording means for recording on the same recording medium together with the respective image signals, reproducing means for reproducing the image signals and the shift information from the recording medium, and reproducing the reproduced image signals obtained from the reproducing means simultaneously. Image processing means for performing a shift conversion process reverse to that at the time of imaging based on the obtained shift information, and combining the applied signals into one image signal. Wherein the image information recording and reproducing system. In order to achieve the above object, according to the second aspect of the present invention, an image is taken at an optimum exposure value by an automatic exposure control, and an image is taken at an exposure value shifted by a predetermined amount with respect to the optimum exposure value. The image signals of a plurality of screens, and the respective image signals from the recording medium recorded on the same recording medium by adding shift information indicating a shift amount and a shift direction with respect to the optimum exposure value to each of the plurality of image signals. An input unit for inputting the image signal and the shift information reproduced from the recording medium, and each of the input signals obtained from the input unit based on the shift information input from the input unit. The image information reproducing apparatus is characterized in that the image information reproducing apparatus includes a processing unit that performs a reverse shift process on the image signal of the screen and that synthesizes the image signal of each screen. In order to achieve the above object, according to the invention described in claim 3 of the present application,
An image pickup means for picking up an image of an object at an optimum exposure value by automatic exposure control, and also picking up an exposure value increased or decreased by a predetermined amount with respect to the optimum exposure value, and continuously picked up images while changing the exposure value by the image pickup means. A recording means for adding, to each of the plurality of imaging signals, shift information indicating a shift amount and a shift direction with respect to the optimum exposure value, and recording the information together with the imaging signals on the same recording medium. Features.

[0007]

According to the present invention, at the time of imaging and recording, an image is taken under the control of an optimum exposure value, an image is taken at an exposure amount obtained by increasing or decreasing a predetermined amount of light with respect to the optimum exposure value, and these imaging signals, the shift amount and The shift direction is recorded on the recording medium, and at the time of reproduction, image processing is performed on the reproduced image signal based on the shift amount and the shift information of the shift amount. An image signal having a gradation range equivalent to the gradation expression of a subject can be reproduced even by using an image pickup recording system capable of picking up or recording only a narrow range.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

As an embodiment, an 8 mm video PCM-S is used.
A case where the present invention is applied to a video printer will be described below by taking as an example a system called an "V system" for simultaneously recording an analog moving image signal and a digitized PCM still image signal on a tape.

FIG. 2 shows a recording track pattern on the 8-mm video tape 41. First, referring to FIG.
A description will be given of how various types of information are recorded in the order in which recording tracks are formed obliquely upward from below the millimeter video tape 41.

(1) PCM area The PCM area is an area where digital data is recorded at a data rate of 0.5 Mbps to 1.5 Mbps. In this PCM area, as shown in FIG.
It quantizes stereo audio or digital still image information (Audio DAT) of a field frame.
A), ID words of subcode information related to these information (for example, sound quality, image quality, and shooting date) (ID),
Sync for data reconfiguration (Sync.), Address (A
address), PQ parity for error detection (P,
Q), CRCC for error correction, and the like.

(2) INDEX area The INDEX (index) area basically includes the P
It uses the same technology as CM recording, and is composed of a search signal for search and a data signal for recording various types of information described below. As shown in FIG. 2, the search signal (SEARC)
H) is a normal state when all 0s are set, and a cueing signal is input when all 1s are set. The data signal (DATA) is provided with five data blocks BL0 to BL4 sandwiched between an S: start block and an END: end block, and each block is composed of data words WD0 to WD4 and CRCC.

Since each of the data words WD0 to WD4 has a capacity of 8 bits (bits), information relating to an increase or a decrease in the amount of light can be recorded using this area. For example, assuming that the shift direction is 1 bit as a positive / negative sign, and the shift amount is 6/4 assuming a maximum value of 16 stops in 1/4 stop steps.
It can be expressed by a total of 8 bits, assuming that each bit is a bit, and the presence or absence of a shift is 1 bit. In addition to the above shift information, the number of printouts and the like can be set by the after recording operation of the INDEX area.

(3) VIDEO area In the VIDEO (video) area, as shown in FIG. 2, an analog video signal is allocated as a luminance FM (YFM) and a low frequency conversion color signal (C), and an analog audio signal is allocated. Monaural FM or sum and difference stereo signal (L + R, LR) FM
The frequency spectrum is arranged as audio multiplexed (main, sub) FM (AFM) and a four-frequency pilot signal (4f) for tape tracking during reproduction is arranged in the lowest frequency band.

The above (1) on the 8 mm video tape 41
The information areas (3) to (3) can be independently recorded / reproduced. For example, a digital still image can be additionally recorded on a tape on which only analog information is recorded, or PCM audio can be recorded after-recording (after-recording). Further, it is also possible to later specify a cue signal for designating a screen for printout, a print size, the number of prints, and the like for a tape that has been shot or edited.

FIG. 3 shows a circuit configuration of a recording system of the image information recording / reproducing system according to one embodiment of the present invention. Next, with reference to FIG. 3, a description will be given of a process at the time of recording information according to an embodiment of the present invention.

A video signal picked up by the video camera 20 is subjected to well-known signal processing for 8 mm video by an analog recording processing circuit (video circuit) 34.
The audio signal picked up by the microphone 31 is amplified by an amplifier (amplifier) 32 to perform signal processing for a well-known 8-mm video by an audio processing circuit (audio circuit) 3.
3. The four-frequency pilot signal 4f from the well-known 8-mm video tracking servo circuit 38 is added to the output signal of the audio circuit 33 and the output signal of the video circuit 34 in the adder 36, thereby obtaining the above-mentioned VIDEO (video) area ( A signal to be recorded in 3) is generated and supplied to a time-division signal distributor (SW3) 37.

When information such as a calendar and a clock used for the so-called auto date function of the video camera 20 is input from the key input switch 46 to the system controller 42, the system controller 42 uses the index information generation circuit 35 based on this information to execute the above-described operation. The information to be recorded in the INDEX (index) area (2) is generated, and the generated information is supplied to the time-division signal distributor 37. At this time, the operator uses the key input switch 46 to perform the various settings described above regarding the printout.

In the PCM recording of the audio signal, the output of an amplifier (amplifier) 32 is output to a PC by a selection circuit (not shown).
The signal can be sent to the M processing circuit 29, and the system controller 42 can switch the input audio signal to the PCM processing circuit 29 with still image information, which will be described later, in accordance with the key input of the key input switch 46. Since the PCM processing of 8 mm video itself is a known technique, it is omitted in this embodiment for the purpose of simplifying the description.

A video signal picked up by the video camera 20 is converted into a digital video signal by an A / D (analog / digital) converter 21. Timing specified by key input switch 46 (shutter release)
Or automatically generates the interval pulse generated by the frame memory 22 through the system controller 42.
In response to this, when the writing of the target screen is completed, the writing to the frame memory 22 is prohibited, and the digital video signal of the still image (SV) or the slow moving image is transferred from the frame memory 22 of the digital video signal. Is taken in. The screen fetched from the frame memory 22 is switched by a switch (SW) as needed in an EVF (electronic viewfinder) 45 displaying a normal moving image.
2) It is possible to select and display a monitor as appropriate by switching 48.

The above-described EVF 45 is attached to the video camera 20 and often has a simple configuration mainly for framing. Specifically, 0.5
EVF45 is a screen with a small size of about 1 inch to 1 inch, and often has a black and white display, which is insufficient in performance for confirming the gradation expression and color skipping of the imaging screen.
As a countermeasure against such characteristics, color skipping can be minimized by controlling the imaging optical system, and imaging at the optimal exposure amount that is considered to be the best in gradation expression, and before and after this optimal exposure amount (I.e., three types of imaging) in a situation where the set value is intentionally slightly shifted to the value of (1). In order to realize this by a video camera, the frame memory 22 is used as a buffer memory for three screens so that the frame memory 22 is
The configuration is made up of three screen memories b and 22c.

For example, when the set value is shifted in both the positive and negative directions with respect to the optimum value which is considered to be the optimum exposure amount, and three screens are taken together with the optimum value, + shift, appropriate value,-
The three screens of shift are shot continuously in a short time,
The data is stored in each of the three memories 22a, 22b, 22c. It takes time to record the information of the three screens on the tape 41. Therefore, after the recording of one screen read from the memory 22a is completed, the information of the second screen is stored in the memory 22a.
b, and sequentially recorded on the tape 41 in the same manner. This is shown in FIG. As shown in FIG. 4, when the moving image (MV) and the still image (SV) are independently captured, the images are captured while changing the exposure amount, and the memories 22a and 2
2b, 22c sequentially, read it out, 8 bit
Is recorded on the tape 41 together with the discrimination code.

However, in the case of performing the above-described shift photographing of a moving image while photographing the moving image, SV (1) ⁺
There MV1, SV (1) is MV2, SV (1) ^- is MV3
, So that the moving image
Some unnaturalness occurs. Therefore, by design, a decision to permit shift shooting only in the recording mode for only still images may be added to the system control rule.

FIG. 5 shows a conventional PCM-SV for comparison.
4 shows a recording track pattern. As a specific example, FIG.
The compression ratio of the still image data in FIG. 4 is set higher than the compression ratio of the still image data to reduce the recording processing time in the entire shift shooting. Therefore, by design, a control rule that automatically selects a compressor with a high compression ratio when the shift photographing mode is selected may be added to the system control rule.

The eight-digit number (for example, 1100 0001) shown between the MV area and the SV area (INDEX area) in FIGS. 4 and 5 is the above-mentioned 8-bit shift information. Here, (1100 0001) indicates that the image was taken shifted by one stop to the positive side, and (0000)
0000) indicates that the image was taken with proper exposure,
It is assumed that (1000 0001) indicates that the image was taken with one stop shifted to the negative side.

Next, the frame memories 22a, 22b, 2
The above-mentioned SV data read from 2c is supplied to the first and second image data compression circuits 23a and 23b, where the data is compressed, and further, the three types of uncompressed raw data are used.
The data is supplied to the mode selection circuit (SW1) 24 as V data.
Is switched to one of the SV data and selectively output by the system controller 42 in response to the mode input.
The image data selected here is sent to a data interface module (hereinafter referred to as I
/ F). On the other hand, the system controller 42 transmits the mode information (uncompressed, compressed 1,
(Difference in compression 2) to the subcode data generation circuit 30 and write it into the PCM area (see FIG. 2) together with the SV image data as the ID word (subcode) of the PCM data together with the date information such as the above-mentioned auto date. PC
The processing is performed in the M circuit 29. The above-described image data transmitted from the I / F 25 via the data bus 26 and the I / F 27 is converted into 0.5 to
The data rate is converted to a data rate of 1.5 Mbps (megabits / second), supplied to the PCM processing circuit 29, subjected to PCM signal processing together with the above-described subcode, and supplied to a time division signal selection circuit (SW3) 37 having a switch function. Is done.

The time-division signal selection circuit (SW3) 37 sequentially transmits information from the PCM area, the INDEX area, and the V-direction in the head scanning direction to form the recording track pattern shown in FIG.
PCM information, INDEX information, and VIDEO information are selected according to the IDEO area, and the recording rotary drum 39 is selected.
The data is supplied to the heads 40a and 40b provided thereon, and a track pattern is formed on the tape 41 as shown in FIG.

FIG. 5 shows an example in which only a specific screen designated by a key operation of the key input switch 46 is digitally recorded. This drawing conceptually shows the SV (3) recording pattern when the shutter button is pressed so as to record a still image in the third field. In this example, FIG.
The second compression circuit 23b having a compression ratio of 1/2 of the first compression circuit 23a used in the mode (the image quality deterioration is smaller).
, The moving image track No. 3-No. 12
1 screen is recorded using a PCM area over 10 fields. In the recording in the INDEX area, 8-bit all 0s indicating that the image was shot with proper exposure are recorded.

FIG. 6 shows the internal configuration of the video camera 20 shown in FIG. In FIG. 6, subject light transmitted through an imaging optical system 201 is subjected to light amount control by an iris (aperture) mechanism 202 as first exposure amount adjusting means, and
In the camera signal processing circuit 204, the signal is converted into a television signal. This television signal is output to the output terminal 213 of the video camera 20.
AE (automatic exposure) control circuit 205 and AF (automatic focus adjustment) mechanism 2
06 as a feedback signal. An AE control signal and an AF control signal are output from each of the control circuits 205 and 206 in response to the television signal, an iris motor 208 is driven by the AE control signal, and a focus motor 209 is driven by the AF control signal. The circuits 205 and 206 detect whether or not the control target values are at respective control target values based on the respective detection signals of the iris sensor 207 and the focus lens sensor 210.
By adjusting the control signal and the AF control signal, the imaging system is always controlled so as to maintain the optimum value.

A camera microcomputer (hereinafter, referred to as a camera microcomputer) for outputting a control signal to each section in response to an instruction from the system controller 42 shown in FIG. When performing shift shooting, the camera microcomputer 211 controls the AE control circuit 2 to make parameters other than the exposure amount constant.
05 and a lock instruction signal to the AF mechanism 206, thereby holding the motors 208 and 209.

The determination of the video signal level is performed by the iris 202
Aperture, the speed of the electronic shutter, and the amplification factor (gain) of an AGC amplifier (not shown) in the camera signal processing circuit 204. Therefore, the camera microcomputer 211 first issues a lock instruction for fixing the gain of the AGC amplifier in the camera signal processing circuit 204. On the other hand, the camera microcomputer 211 gives a shutter speed shift instruction to the image sensor 203 so that the exposure amount can be changed instantaneously. For example, if the aperture is one for positive and negative, the appropriate shutter speed is 1/250 second and 1/500 → 1/250 →
If it shifts to 1/125 second and 3 stages, +1 stop,
The imaging of the exposure shift of the appropriate value, -1 stop, can be executed.

Next, FIG. 7 shows the concept of the synthesis of the dynamic range of the three exposure values imaged as described above. Here, the range a is a +1 stop shift, and the illuminance level is 3 to
10, the range b is an appropriate value and covers the illuminance levels 2 to 9, and the range c is a -1 aperture shift and covers the illuminance levels 1 to 8. For this reason, in this embodiment, the range d covering the illuminance levels 1 to 10 is obtained by combining the images captured in the ranges a, b, and c.
Is generated.

FIG. 8 shows a circuit configuration of a reproducing system of the image information recording / reproducing system according to one embodiment of the present invention.
Connected to the circuit. Next, a process at the time of information reproduction according to an embodiment of the present invention will be described with reference to FIG.

It is assumed that information tracks as shown in FIG. 2 are formed on the magnetic tape 41. Servo circuit 3
By controlling the capstan 19 and the rotating drum 39 by the 8, the information track is tracked, and recorded on the magnetic tape 41 by the recording / reproducing heads (magnetic heads) 40 a and 40 b provided on the rotating drum 39. Detecting information signals. Head 40
The signals detected at a and 40b are the switches (SW4) 50
Thus, the signal is distributed to the PCM area, the INDEX area, and the VIDEO area in a time-sharing manner according to the information content of the detection signal.

The analog signal in the VIDEO region distributed by the switch 50 is further divided in frequency spectrum by a distributor 51. The pilot signal 4f is supplied to the servo circuit 38 from the lower frequency, and the color information C is supplied to the video circuit 53. The audio information AFM is supplied to the audio circuit 52, and the luminance information Y is supplied to the video circuit 53 in the same manner as the chrominance information C. Each circuit performs well-known 8-mm video signal processing. . As a result, the video signal and the audio signal with good tracking are output to the output terminal 7.
4, 73 respectively. The video signal is appropriately switched by a switching signal of the system controller 42 via still image information described later and a switch (SW2) 48,
It can be selectively displayed on the screen of the image motor device 12. As another embodiment, the video circuit 53 may perform image processing such as well-known small-screen synthesis (Picture in Picture) as a matter of course.

The signals in the INDEX area are reproduced by the INDEX signal processing circuit 56 into a data group as shown in FIG. 2, and the camcorder (C / C) system controller 42
To the INDEX information. In the system controller 42, the cueing operation for print output is performed under the control of the servo circuit 38 until the search signal (for example, all "1" data) written in the INDEX area is detected. , And performs its detection. When all "1" s of the search signal are detected, the INDEX signal processing circuit 56 reads the print information (number of prints and size) set in the data area, and transfers the print information to the camcorder system controller 42. . The data of these print information is sent to the data bus 26 via the data interface (I / F) 43, and is taken into the video printer unit 14 as needed.

The signal in the PCM area is supplied to the PCM signal reproducing circuit 5.
In step 4, the reproduction process is performed on the SV information as the main data and the ID word as the subcode data. The data of the SV information is subjected to a data rate conversion process reverse to that at the time of recording by the rate conversion circuit 57, and the audio rate (0.5
M to 1.5 Mbps) so as to conform to the data rate of the data bus 26, and the interface (I / I /
F) and is sent out onto the data bus 26 via 27).
At this time, the still image information is transferred to the video printer unit 14 via the data bus 26 in a state of being compressed together with the compression mode information (excluding the non-compression mode).

On the camcorder side, for monitoring the reproduced still image, the still image information is transmitted via the interface (I / F) 25, and the control information is transmitted via the interface (I / F) 44.
To the next-stage image expansion processing system. The switch (SW5) 76 is switched in accordance with the compression mode of the control information, and the original image information is substantially expanded and restored by the non-compressed information and the first expansion processing circuit 58 (or the second expansion processing circuit 59). The selected information is supplied to the frame memory 22. The selection output signal of the switch (SW5) 76 is stored as a still image of one screen on the frame memory 22, read out at a video rate by a D / A (digital / analog) converter 60, and converted into analog image information as described above. As shown in FIG. This analog image information is displayed as a still image on the image monitor device 12 such as an EVF via the switch 48 as needed.

The analog video signal output from the video circuit 53 also specifies a still screen by inputting a cue signal or the like into an arbitrary screen in the moving image signal, and the A / D converter 7
5, the data is supplied from the interface (I / F) 27 to the data bus 26, and can be printed out in the same manner as uncompressed digital still image data.

Next, the operation of the video printer unit 14 shown in FIG. 8 will be described.

The above-described digital image information and control data accompanying the image information are transmitted via interfaces 27 and 43. A general video signal input from a conventional analog video input terminal 78 is digitized by an A / D (analog / digital) converter 61, captured by a one-screen memory 62, and the captured still image ( The digital image information is transmitted via the interface 63. The transmitted video signals are placed on the data bus 26 of the video printer. Data bus 26
Among the above information, the image data is interface 6
4 via the buffer memory 65 of the video printer 14
The control data is taken into the system controller 67 of the video printer via the interface 66.

The buffer memory 65 sends information (Free Capa) on the free space of the memory to the system controller 67 so that the memory occupation state due to data storage can be managed by the system controller 67. As described above, the image data once stored in the buffer memory 65 is subjected to data expansion processing reverse to that at the time of recording by the first expander 68 and the second expander 69 under the control of the system controller 67. 65
Are switched and selected by the expansion circuit selection switch (SW6) 70 together with the non-compression data read out from the memory, and are stored on the frame memory 71 through the shift circuit 77 as reproduction still image information. Using the still image information stored in the frame memory 71, a printing unit 72 controlled by a printer system controller 67 generates and records a video print image on a recording medium such as paper. As the printing unit 72, for example, an ink jet printer, a laser beam printer, or the like can be applied.

Next, a printing process in the case where the data obtained by performing the above shift photographing is supplied to the video printer unit 14 will be described.

In this case, in response to the output from the expansion circuit selection switch 70, the printer system controller 6
In accordance with the sign (shift direction) and the amount (S shift amount) of the shift information supplied from 7, the shift circuit 77 performs reverse shift conversion (reverse shift conversion) at the time of imaging. The result of the conversion processing is sequentially stored in the frame memory 71 for three screens while being combined.

That is, in this embodiment, since the first screen is shifted by +1 stop, the inverse conversion processing of the shift processing of one step in the forward direction is performed, and the result is stored in the frame memory 71 initialized. Next, since the second screen is properly exposed, the first screen information is once read out from the frame memory 71 without being subjected to the inverse conversion shift, and added to the second screen information in the shift circuit 77, and The addition result is again stored in the frame memory 71 by the read-modify-write function or the like. Similarly, on the third screen, since the third screen is shifted by -1 stop, the inverse conversion processing of the shift processing of one step in the negative direction is performed, and the reverse conversion processing is performed on the composite image information of the first image information and the second image information. Are further combined, and the combined image information is stored in the frame memory 71 again.

In the present embodiment, image information having three different ranges can be synthesized by the procedure described above to generate image information having a wider dynamic range. This image information is read from the frame memory 71 and printed out on a recording medium by the printing unit 72. In this way, an image with rich tones can be reproduced on paper.

FIG. 9 shows the principle of expanding the dynamic range according to the present invention. FIG. 9 shows information conversion characteristics (a) to
(D) is shown. Arrow R ₀ shown in the lower part at the center of the figure.
Indicates the range of the gradation that the subject originally has. With this range as a starting point, the principle of expanding the dynamic range is converted through (a) → (b) → (c) → (d). I will explain along the procedure.

The above range R ₀ is from the dark part Y ₁ to the light part Y ₂
Expresses the gradation between. In contrast, the image sensor 20 shown in FIG.
3 are converted to straight lines (a1), (a
Shown as 2). Here, the vertical axis is the range of the input light, and the horizontal axis is the range of the output light. In this, according to the exposure amount setting, range from y ₁ and R ₁ to y _3, the positive side shifted range from y ₂ more bright portion of reproducibility exposure amount setting increased to y ₄ the case of imaging the two R ₂ shown in the example.

The range y ₁ of R ₁ corresponds to Y ₁ of the range R _0, range y ₄ for R ₂ corresponds to Y ₂ of the range R _0, range R ₁ and ends at range R ₂ Each exposure amount is set so as to cover the entire region R ₀ . When the setting of the exposure amount is shifted to the positive side from the straight line a ₁ of the conversion characteristic of the image sensor 203 to a ₂ by the amount corresponding to the arrow S ₁ , the image sensor 20
The range after photoelectric conversion in 3 is the range R ₃ . The characteristic curve (b) at the upper right of FIG.
0 shows an example of a non-linear characteristic in the camera signal processing circuit 204, which is represented by a γ-conversion and a knee characteristic, where the dynamic range is compressed. As a result, the television signal dynamic range that range R ₄ is compressed is generated.

In FIG. 9, a range R ₁ excellent in reproducing the gradation of a dark portion of the subject and a range R ₂ excellent in reproducing the gradation of a bright portion are expressed as the same range R ₃ . In this state, the television signal of the range R ₄ is recorded onto the tape 41 as PCM data.

At the time of reproduction, the processing is the reverse of the above-described recording. That is, the inverse non-linear transformation of the characteristic (b) by the characteristic curve (c) shown in the upper left side of FIG. 9 performs at a rate conversion circuit 57, the range of the video signal which has been compressed to the range R ₄ R
Of ₃ ', extending the dynamic range to a level corresponding to the range R _3.

Next, the linear transformation (d) is performed by the switch 70 and the shift circuit 77 in the form shown by the arrow S2 corresponding to the inverse transformation of the above (a), based on the above-mentioned shift information and the characteristic straight line (d1). ) And (d2) are executed electrically. That is, an electric bias is applied (the above-described shift process) so that the range R ₀ can be reproduced according to the sign and amount of the shift information, and the images of the ranges R ₁ ′ and R ₂ ′ are shifted by the shift circuit 77. And using the frame memory 71.

According to the embodiment of the present invention, such a reproducing process can reproduce a wide gradation which the subject originally had even through a recording system having a relatively narrow dynamic range.

(Other Embodiments) In the above-described embodiment of the present invention, an electronic shutter by clock control of writing and reading of the image sensor 203 is used for instantaneous switching of the exposure amount. However, other means, such as PLZT, are used. An electronically controlled ND filter such as (lanthanum-doped zirconate-lead titanate) or an iris having a fast reaction may be used.

In the above-described embodiment of the present invention, the shift information is recorded in the INDEX area on the magnetic tape.
If the shift information is recorded in the ID word of the CM area itself, the shift information is always processed together with the still image information.
A trouble that shift information is lost due to INDEX dubbing or the like can also be avoided.

In the above-described embodiment of the present invention, the reverse shift is performed in response to the shift at the time of imaging at the time of reproduction. However, the amount of the reverse shift is reduced by making the shift sign the same.
It may be within the dynamic range of the display means of the printer or display.

The present invention is not limited to a video printer,
It is also preferable to apply the present invention to special reproduction viewed on a display such as a stop motion.

[0058]

As described above, according to the present invention,
A shift amount and a shift information indicating a shift direction with respect to the optimum exposure value are added to each of a plurality of imaging signals imaged with the exposure value that is increased or decreased by a predetermined amount from the optimum exposure value, and recorded on the same recording medium and reproduced. At times, each imaging signal reproduced from the recording medium is subjected to a shift conversion process reverse to that at the time of imaging based on the shift information and combined, so that the imaging signal is relatively compared with the gradation range originally possessed by the subject. By using an image-capturing recording system capable of capturing or recording only in a narrow range, it is possible to express the gradation of a subject in a wide dynamic range.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a conventional general video printer.

FIG. 2 is a diagram showing a recording pattern on an 8 mm video tape according to one embodiment of the present invention.

FIG. 3 is a block diagram showing a circuit configuration of a recording system of the image information recording / reproducing system according to one embodiment of the present invention.

FIG. 4 is a diagram showing a recording track pattern on a video tape when there is a shift from an optimum exposure in one embodiment of the present invention.

FIG. 5 is a diagram showing a recording track pattern on a video tape when there is no shift in one embodiment of the present invention.

FIG. 6 is a block diagram showing an internal configuration of the video camera shown in FIG.

FIG. 7 is a diagram showing a concept of synthesizing a dynamic range of three types of exposure values captured in an embodiment of the present invention.

FIG. 8 is a block diagram showing a circuit configuration of a reproduction system of the image information recording / reproduction system according to one embodiment of the present invention.

FIG. 9 is a diagram illustrating an overall operation concept of a shift process executed in an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 20 video camera 22a, 22b, 22c frame memory 23a, 23b image data compression circuit 24 mode selection circuit 26 data bus 28, 57 rate conversion circuit 29, 54 PCM processing circuit 30, 55 subcode data generation circuit 35, 56 index information generation Circuit 37, 50 Time-division signal distributor 39 Rotating drum 40a, 40b Recording / reproducing head 41 Video tape 42 System controller 46 Key input switch 50 Switch 58 First decompression processing circuit 59 Second decompression processing circuit 67 System controller 68 First decompressor 69 second decompressor 70, 76 decompression circuit selection switch 71 frame memory 72 printing unit 77 shift circuit 203 image sensor 204 camera signal processing circuit 205 automatic exposure control circuit 206 automatic focus adjustment mechanism 211 La microcomputer

Claims (3)

(57) [Claims] The method according to claim 1 automatic exposure control in together when imaged with optimum exposure value of an object changes, imaging means for imaging at a predetermined increase and decrease the exposure value for the optimum exposure value, the exposure value by the image pickup means Was imaged
Shift information indicating a shift amount and a shift direction with respect to the optimum exposure value is added to each of the plurality of imaging signals , and
Recording means for recording on the same recording medium together with each imaging signal ; reproducing means for reproducing the imaging signal and the shift information from the recording medium; and reproduced reproduction image signals obtained from the reproduction means simultaneously. An image information recording / reproducing system comprising: image processing means for performing a shift conversion process reverse to that at the time of imaging based on the shift information, and combining the applied signals into one image signal. 2. An image signal of a plurality of screens imaged at an optimum exposure value by automatic exposure control and imaged at an exposure value shifted by a predetermined amount with respect to the optimum exposure value, and the plurality of images
The same recording is performed by adding shift information indicating a shift amount and a shift direction with respect to the optimum exposure value to each signal.
From the recording medium recorded on the medium, re the image signals
An apparatus for raw input means for inputting the image signal reproduced from the recording medium and the said shift information, based on the shift information input from said input means,
Image information, characterized by comprising a processing unit for the performing shift processing of the image at the opposite for each screen image signals obtained from the input means, for synthesizing the image signals of the respective screens
Information playback device. 3. An optimal exposure value of a subject by automatic exposure control.
And increase by a predetermined amount with respect to the optimal exposure value.
Imaging means for imaging even with a reduced exposure value; and shift information indicating a shift amount and a shift direction with respect to an optimum exposure value for each of a plurality of imaging signals continuously imaged while changing the exposure value by the imaging means. was added and the image information, characterized by comprising a recording means for recording on the respective image pickup signals with the same recording medium
Information recording device.