JPS63263989A - Image converting circuit device - Google Patents

Abstract

PURPOSE:To obtain sharp, high saturation and excellent picture quality in any cases of a negative film, a positive film and an actuality film by setting switchably vertical contour correcting quantity and horizontal contour correcting quantity to two steps for the positive and the negative and synchronizing it with the switch of a color inverting circuit. CONSTITUTION:When a color negative film 66 is exposed, a negative/positive change-over switch 70 is switched to the negative. By an analog switch 17, an inverting circuit 16 is activated and analog switches 71 and 74 are switched. A color inverted signal is sent to a matrix circuit 12 and a luminance signal and a color difference signal are generated. From a volume 68 selected by the switch 71, a voltage for adjusting a negative vertical contour is inputted, an contour correcting signal in a vertical direction is amplified in corresponding to the characteristic of the film 66 and the vertical correction is executed. An encoder 13 convertes a vertical contour corrected luminance signal and a color difference signal to the signals of the systems of NTSC, etc. Simultaneously, to the encoder 13 from a volume 72 selected by the switch 74, a voltage for adjusting a negative horizontal contour is inputted and a contour correcting signal in a horizontal direction is, in the same way, horizontal contour corrected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is used in an imaging/transmission circuit of a television camera that images general subjects, bodies, and color films, and in particular,
This invention relates to an image conversion circuit device that faithfully transmits a negative image of a color negative film to a positive image by 5 inversions with a simple circuit configuration, and can obtain a video signal with no difference between a color negative film and a color positive film/actual photograph. It is.

[Prior Art] Film programs for television broadcasting have various advantages such as omitting the printing process and improving color reproducibility. Therefore, instead of the conventional color positive film, a color negative film is directly exposed to a television camera and the negative image is converted into a positive image. The image is transmitted while being inverted. However, due to the nature of the business in television broadcasting, it is necessary to handle many types of film with different characteristics, and it is not enough to simply reproduce the film, but to reproduce the subject itself as a natural-looking color image on the television screen. Therefore, the entire circuit including the color inverting circuit has a very complicated structure.

On the other hand, with the widespread use of compact color TV cameras for household and industrial use, the demand for compact TV cameras with color reversal functionality is increasing, and research into incorporating color reversal circuits with simple configurations is actively being conducted. It is progressing.

Figure 17 shows an example of the circuit configuration of a small television camera having the above-mentioned color inversion circuit. High-voltage block c1 Amplifier d1 for amplifying the video signal Synchronous signal generator e1 A Y signal processing circuit r that separates the three color components sent from the amplifier d and combines them to create a luminance signal, also separated. Chroma signal processing circuit h1 that combines color components to create a color difference signal Y/C mixing circuit 1 that superimposes a color difference signal on the luminance signal
1 outputs a two-way composite video signal, and
It consists of a video output circuit j that produces VF output, etc.
An inversion circuit 1 for color inverting the luminance signal is incorporated in the Y signal processing circuit r, and an inversion circuit 2 is incorporated in the chroma signal processing circuit r for inverting the color difference signal.

[Problems to be Solved by the Invention] However, when the colors of a color negative film are inverted using the circuit described above and reproduced on a television screen, the projected image lacks luster and the overall tone is dull and sleepy. There was a problem that satisfactory image quality could not be obtained.

Although thorough studies have been carried out to elucidate the cause of this poor image quality, no clear conclusion has been reached. It is speculated that color mixing may have occurred somewhere due to the operation.

In addition, in the case of a color negative film that uses a development inhibitor-releasing coupler, as shown in FIG. The development inhibitor generated on the side of the highly exposed area m where development is proceeding crosses the boundary and diffuses to the side of the lightly exposed area n as shown by the solid line arrow, and the development of the low exposed area n is suppressed. The developer with less development inhibitor diffuses from the n side to the high exposure area m side as shown by the broken line arrow, and the image density of the high exposure area m near the boundary increases, and the density difference at the boundary increases, resulting in an edge effect. This results in sharper images.

In the case of color positive films such as color reversal films, when development of silver halide occurs, development inhibitors such as halogen ions are released and the boundaries of the image are hemmed to inhibit development in the surrounding area, a phenomenon known as the adjacency effect. , and the periphery of the image appears visually sharp. Adjacency effects are controlled by controlling the diffusion distance of the development inhibiting substance.

As described above, since the image contour characteristics of negative film and positive film are different, contour compensation is required for each material when these materials are imaged with a video camera and displayed on a receiver.

[Means for Solving the Problems] In view of the above-mentioned problems, the present invention provides an image conversion circuit device capable of reproducing color inverted images with high sharpness and good image quality for both negative and positive images with a relatively simple configuration. The configuration is such that an image conversion circuit device for a color video camera having a negative/positive inversion circuit is provided with a vertical contour correction circuit and a horizontal contour correction circuit, and the amount of vertical contour correction by the vertical contour correction circuit and the above-mentioned The present invention is characterized in that the amount of horizontal contour correction by the horizontal contour correction circuit can be changed over at least two levels in synchronization with the switching of the inversion circuit.

[Function] In the case of color positive film, the video signal captured by a color video camera and extracted from a photoelectric conversion device is converted as is.
In the case of color negative film, the polarity of the electrical signals is reversed for each electrical signal flow, eliminating the risk of unpredictable color mixing. Since the contour is corrected and the horizontal contour is corrected in the horizontal contour correction circuit, appropriate contour correction is performed in both positive and negative cases, and a color image with sharp image quality can be reproduced.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. 1st
Figures 11 to 11 show an embodiment of the present invention. )
, 3 is a synchronization signal generator, 4 is a timing generation circuit for supplying the synchronization signal, 5 is a storage device for cooperating with this circuit 4 to cover a partial defect in the CCD 1, 6 and 7
8 is a V driver and an H driver for horizontal scanning and vertical scanning (in this embodiment, interlaced scanning for each horizontal scanning line) of the photoelectric conversion surface of the CCDI, and 8 is a red, green, and red pixel signal sent from the CCDI. a signal processing circuit that separates the blue component and creates three types of color signals R (red), G (green), and B (blue), and also cooperates with the white balance control circuit 9 and the auto iris/auto white BL circuit 10; 1
2 is a matrix circuit that combines the signals G, R, and B sent from the signal processing circuit 8 to create a luminance signal and a color difference signal; 13 is a matrix circuit that converts the color difference signal sent from the matrix circuit 12 into a carrier color signal, and converts the color difference signal sent from the matrix circuit 12 into a carrier color signal; Superimposed on the luminance signal N
Encoder that creates TSC system or other system signals, 14 is a fader circuit for fading in and out the reproduced image, ■ 5 is a signal that synchronizes 3H (3 horizontal scans) and synthesizes signals that are not in IH. The signal processing circuit 8 and the matrix circuit 12 are an IH delay line circuit for
An inverting circuit 16 for color inverting the red, green, and blue color signals and an analog switch 17 for switching between negative and positive for selectively using the inverting circuit 16 are arranged between them. As shown in FIG. 3, the CCD color filter 2 has striped windows 9 for passing green light, and a window r for passing red light or a window r for passing blue light between each window 9. , are arranged alternately every two lines arranged in the vertical direction. Note that the window arrangement of the color filter 2 may be arranged in a different arrangement than the above arrangement.

The signal processing circuit 8 includes a sample-and-hold circuit (not shown), an RGB gain control, a γ compensation circuit (can be set separately for negative and positive), a white balance circuit, and others. Color signals Gγ, Rγ, and Bγ (the subscript γ indicates a signal subjected to γ correction) shown as a model in the figure are output. in this case,
Gγ is an output line 18 provided individually for each horizontal scan.
(a part of which is shown at the left end of FIG. 2), and Rγ and Bγ are output alternately for each horizontal scan, and this output is passed through a common output line 19. Sent to the downstream circuit. In addition, 20.20 in Fig. 4 shows the black level of the signal, and 22 shows the waveform of the color signal (the actual waveform is C
According to the arrangement of colors distributed on the horizontal scanning line of the photoelectric conversion surface of the OD, a complex shape is shown, for example, as shown by virtual lines).

As shown in FIG. 2, the inverting circuit 16 inverts the flow of color signals Gγ sent one after another through the aforementioned line 18 into color signals having approximately complementary colors, and amplifies them to a predetermined voltage level. , the obtained inverted color signal Gγ is sent to a separate line 23
Gγ inverting circuit lea outputs the color signals Rγ and B which are sent one after another and alternately through the common line 19.
The flow of γ is led to two circuits 24.25 branched from the middle, and within each circuit 24.25, Rγ and Bγ are each inverted into color signals having a substantially complementary color relationship, and amplified to a predetermined voltage level. Rγ/Bγ inversion circuit 16 which merges the obtained inverted color signals Rγ and Bγ into a common line 27 via analog switch 2B and outputs them alternately. Consists of b.

The components of each circuit 16a and IBb described above are as follows:
Amplifiers 17b and 17c of the inverting circuit 16b are the inverting circuit le.
The Gγ inverting circuit l
The circuit configuration of only ea will be explained. Furthermore, regarding the reference numerals and symbols of the constituent elements of each inverting circuit IBa and 16b, the same reference numerals and symbols are given to the constituent elements that perform the same functions.

Gγ inversion circuit 16. a indicates the buffer amplifier 2B provided at the circuit entrance, the clamp circuit 29 that fixes the black level of the input signal to a predetermined DC voltage level, the buffer amplifier 30 provided after this clamp circuit 29, and the polarity of Gγ. an inverter 32 that inverts the polarity of the signal 3
3 (see FIG. 5), and performs H blanking of the signal flow in the time axis direction in synchronization with the start and end points of each horizontal scan. and a white clipping circuit 38 and a black clipping circuit 39 which respectively clip the white level vicinity 36 and black level vicinity 37 of the color signal 35 (see FIGS. 6 and 7) obtained by the above operation, and the color signal 35 obtained by this operation. signal 40
(See FIG. 7) consists of an amplifier 17a that amplifies the voltage to a predetermined voltage level as described above, and a buffer amplifier 42 provided at the circuit outlet. In addition, Cp in the figure is a clamp pulse, Bp is a blanking pulse, 43 is a gain adjustment,
44 is offset adjustment, ID is Rγ.

This is an ID pulse for identifying Bγ.

The matrix circuit 12 is equipped with a vertical contour correction circuit. The principle of the vertical contour correction circuit is as shown in FIGS. 9 and 10, the input video signal is passed through a delay unit, the IH delayed video signal and the 2H delayed video signal are taken out, and the input video signal and the 2H delayed video signal are output. The signals are averaged, the average video signal is subtracted from the IH delayed video signal to obtain a vertical contour correction signal, and the IH delayed video signal is added to the correction signal to obtain a vertical contour corrected video signal. The vertical contour correction circuit is configured as shown in FIG. 11, for example. In Fig. 11, 75° 76 is one horizontal scanning time delay line, 77 is a delay line, 78, 79.80 is a volume, 81 is a subtracter, 82 is a low-pass filter, 8
3 to 90 indicate amplifiers. Since the amplification amount of the vertical contour correction circuit can be changed by adjusting the voltage, volumes 68 and 69 are provided in parallel with the adjustment voltages 67 of 2V and 3V, and one volume 68 is set for negative film (for example, 2V and 3V).
．． 5V) L, the other volume 69 is set for positive film (for example, 2.6V), so that it can be switched by the analog switch 71 which is switched in conjunction with the analog switch 17 by the negative/positive changeover switch 70. . The matrix circuit 12 used here is, for example, SLI CX20151 manufactured by Sony Corporation.

Further, the encoder 13 is equipped with a horizontal contour correction circuit. The horizontal contour correction circuit has the same principle as the vertical contour correction circuit, and as shown in FIGS. 12 and 13, it processes a video signal delayed by 180 ns and a reflected video signal delayed by 380 ns from the input video signal. take out,
A horizontal contour correction signal is obtained by performing addition and subtraction substantially similar to the vertical contour correction signal, and a 180 ns delayed video signal is added to the correction signal to obtain a horizontal contour corrected video signal.

The horizontal contour correction circuit is configured as shown in FIG. 14, for example. In Figure 14, 91 is a 180ns delay line;
92 is a volume, 93 is a subtracter, 94 to 97 are amplifiers, and 98 is a resistor for input impedance matching of the 180 ns delay line 91. Since the amplification amount of the horizontal contour correction circuit can be changed by voltage adjustment as well, volumes 72 and 73 are provided in parallel with the adjustment voltages 67 of 2V and 3V, and one volume 72 is set for negative film (for example, 2.73). 5V)L, and the other volume 73 is set for positive film (for example, 2.BV), and the analog switch 74, which is switched in conjunction with the analog switch 17, 71, by the negative/positive changeover switch 70, can be used. do it like this. The encoder 13 used here is, for example, LSI CX manufactured by Sony.
There is 20055.

In the figure, 75 is a resistor, and 76 and 77 are diodes.

In the above, as shown in FIG. 15, a circuit that obtains delayed video signals of 150 ns and 300 ns from an input video signal and obtains a video signal subjected to horizontal contour correction through similar processing can also be used as the horizontal contour correction circuit. Further, although the vertical contour correction circuit is attached to the matrix circuit 12 and the horizontal contour correction circuit is attached to the encoder 13, these circuits can be made independent, and can be adapted to various circuit configurations as appropriate. Further, the inverting circuit 16 is not limited to being provided between the signal processing circuit 8 and the matrix 12, and may be provided, for example, on the input side of the signal processing circuit 8 or on the matrix circuit 12.
It may be provided on the output side of the circuit, and can be inserted at an appropriate location depending on each circuit system and circuit configuration.

Next, an example of an image conversion circuit device incorporating the above circuit device will be explained based on FIG. 1 and FIG. 16. CCDI
The color filter 2 is housed in a television camera head 52 together with a lens device 51, and most of the circuit devices described above are made of a hollow column that supports the television camera head 52 swingably around a horizontal axis 53. The film carrier 5B, a light source device 57, and various knobs for operation and adjustment are arranged on a base 55 disposed within the support column 54 and supporting the support column 54. Note that the RGB volume adjustment knobs eo, etc. that constitute a part of the knobs mentioned above
, es are for manually adjusting each RGB gain control (not shown) provided in the signal processing circuit 8, and a fader operation knob 59 is for manually adjusting the fader circuit 14, respectively. Further, the negative/positive changeover switch 70 can be operated in synchronization with the analog switch 17 for the inverting circuit 16, the analog switch 71 for vertical contour correction, and the analog switch 74 for horizontal contour correction.

Note that when capturing an image of a general subject using this image conversion circuit device, the television camera head 52 is swung around a horizontal axis 53 so that the optical axis 64 of the lens device 51 is directly facing the subject. (See phantom line).

Next, the operation of this circuit device will be explained.

First, when photographing the color negative film 6B, the negative/positive changeover switch 70 is switched to negative. As a result, the analog switch 17 operates the inverting circuit 16, and the analog switches 71 and 74 switch the contour correction adjustment voltage to the negative voltage.

Light that enters the color negative film 66 from the light source device 57 through the cyan filter 65 passes through the lens device 51 and the color filter 2, and remains as a negative image color-coded into red, green, and blue on the photoelectric conversion surface of the CCDI. image and accumulate charges on the photoelectric conversion surface.

Then, this charge is interlaced scanned every other horizontal scanning line by the driver 6.7, and pixel signals are sent out to the signal processing circuit 8 one after another.

Here, the sample-and-hold circuit (not shown) is
Window 0 of color filter 2. Using the arrangement of r+b and the timing of arrival of each pixel signal, each pixel signal is divided into red, green,
Separate into blue color signal.

The amplification degree of each separated color signal is controlled, and γ
The corrected signal is output to the inversion circuits lea and 16b.

The clamp circuit 29 of the inverting circuit 111a receives the input Gγ
The black level 20 (see FIG. 4) is fixed at a predetermined reference voltage level, and the inverter 32 then inverts the polarity of the signal (a signal 33 with inverted polarity is shown in FIG. 5). next,
This signal 33 uses a blanking pulse to level shift the black level 20 of the signal 33, and a signal 35 rising upward from the black level 20 is obtained (see FIG. 6). Next, this signal 35 passes through a white clip circuit 38 and a black clip circuit 39, and is clipped near the white level 36 and near the black level 37 as shown in FIG. When the voltage is amplified to a required voltage (voltage necessary to improve the contrast of the image) by 17a, Gγ is obtained (see FIG. 8). In the inverting circuit 1 [ib, each signal Rγ, Bγ is processed in the same way, and the obtained color inverted signals Rγ, Bγ are sent to the common line 2.
7, offset adjustments 44 and 44 provided in the amplifiers 17b and 17c match the black levels of the signals Rγ and Bγ.

Note that if the γ compensation circuit in the signal processing circuit 8 is not configured so that the characteristics of R2O and B can be set individually, it is not possible to install a γ compensation circuit individually after each inverter 32 of the inverting circuit 18a and IBb. It is also possible to improve the tonal characteristics.

The color-inverted signals Gγ, Rγ, and Bγ are sent to the matrix circuit 12, and the matrix circuit 12 combines these signals Gγ, Rγ, and Bγ to generate a luminance signal and a color difference signal. At this time, in the matrix circuit 12, since the negative vertical contour adjustment voltage is input from the volume 68 selected by the analog switch 71, the vertical contour correction signal is amplified according to the characteristics of the color negative film 66. , a vertical correction is made.

Then, the encoder 13 converts the vertical contour-corrected luminance signal and color difference signal into signals of the NTSC system or other systems. At the same time, since the negative horizontal contour adjustment voltage is inputted to the encoder 13 from the volume 72 selected by the analog switch 74, the horizontal direction contour correction signal is similarly amplified according to the characteristics of the color negative film 66, and the horizontal Contour correction is performed.

Therefore, the color television signal or video signal is output with appropriate vertical and horizontal contour correction (
Arrow i): A television receiver receiving these signals projects an excellent image quality with contrast, sharpness, and high color saturation on the television screen.

Next, when printing a color positive film or a real image, the negative/positive changeover switch 70 is switched to positive. This allows the inverting circuit 16 to be
The signal is switched to a signal that does not pass through the analog switch 71.
74, the adjustment voltage for contour correction is switched to positive voltage, and the amplification factor of the contour correction signal is higher than that for negative voltage.

Therefore, the light incident on the color positive film from the light source device 57 with the cyan filter 65 removed is transmitted to the lens device 51.
Then, through the color filter 2, a positive image color-coded into red, green, and blue is formed as it is on the photoelectric conversion surface of the CCD 1, and charges are accumulated on the photoelectric conversion surface. As in the case of a color negative film, this charge is interlaced scanned every other horizontal scanning line by a driver 6.7, and pixel signals are successively sent to the signal processing circuit 8. Each color signal separated from the signal processing circuit 8 has its amplification degree controlled, is further subjected to γ correction, and is directly output to the matrix circuit 12.

The matrix circuit 12 receives the input color signal Gγ.

A luminance signal and a color difference signal are created by combining Rγ and Bγ.

At this time, in the matrix circuit 12, since the voltage for positive vertical contour adjustment is inputted from the polygon 69 selected by the analog switch 71, the vertical contour correction signal or the voltage for adjusting the positive vertical contour is inputted according to the characteristics of the color positive film. It is amplified to a greater extent than in the case of a negative, and vertical contour correction is performed.

Then, the encoder 13 performs horizontal contour correction on the vertical contour-corrected luminance signal and color difference signal, and also performs NTS
Convert to a signal such as C format.

That is, since the positive horizontal contour adjustment voltage is inputted to the encoder from the volume 73 selected by the analog switch 74, the horizontal contour correction signal is also adjusted to a value higher than that for negative according to the characteristics of the color positive film. It is greatly amplified and horizontal contour correction is performed.

In this way, the color television signal (arrow 1) outputted from the encoder 13 has undergone appropriate vertical and horizontal contour correction, so the television receiver receiving these signals will not be able to reproduce the negative image. It is possible to project an excellent image quality image on the TV screen with high sharpness and color saturation with the same level of contrast as the conventional TV screen.

Note that the present invention is not limited to the above-described embodiments; for example, the color filter may be a combination of different colors, and the photoelectric conversion device may be used instead of the solid-state image sensor described in this embodiment. It is possible to use a solid-state image sensor with a different structure or a structure other than a solid-state image sensor, and furthermore, it is possible to incorporate this circuit configuration into other television cameras for telecine use, and various types of devices having a negative ◆ positive inversion circuit can be used. It goes without saying that the present invention can be applied to a video camera having a circuit configuration such as the above, and that various changes can be made without departing from the gist of the invention.

[Effect of the invention] As described above, the present invention exhibits the following excellent effects.

(D) The vertical contour correction amount and the horizontal contour correction amount are set to be switchable in two stages, one for positive film and one for negative film, and are synchronized with the switching of the color reversal circuit. As a result of appropriate vertical and horizontal contour correction, there is good contrast whether it is negative film, positive film, or live action.
Excellent image quality with sharpness and high color saturation can be obtained, and the usability of small TV cameras can be greatly expanded.

■ Can be widely applied to various video cameras with inverting circuits.

[Brief explanation of drawings]

1 to 16 show embodiments of the present invention, FIG. 1 is a block diagram showing the entire circuit device, FIG. 2 is a block diagram of the inverting circuit, and FIG. 3 is the arrangement of color filter windows. 4 is an explanatory diagram of the modeled color signal output from the signal processing circuit, FIG. 5 is an explanatory diagram of the signal obtained by polarity inversion, and FIG. 6 is the H blanking and level shift operation. FIG. 7 is an explanatory diagram of the color signal after applying the white clip and black clip. FIG. 8 is an explanatory diagram of the color signal after color inversion.
10 is a schematic diagram of vertical contour correction based on the principle shown in FIG. 9. FIG. 11 is a block diagram showing an example of the vertical contour correction circuit. Fig. 12 is a principle diagram of horizontal contour correction of the encoder in Fig. 1, Fig. 13 is a schematic diagram of horizontal contour correction based on the principle shown in Fig. 12, and Fig. 14 is a block diagram showing an example of a horizontal contour correction circuit. , FIG. 15 is another principle diagram of horizontal contour correction of the encoder in FIG. 1, FIG. 16 is a perspective view of a television camera incorporating this circuit device, and FIG.
The figure is a block diagram showing an example of a circuit device of a conventional television camera, and FIG. 18 is an explanatory diagram of the edge effect caused by a development inhibitor in a negative film. In the figure, ■ is a solid-state image sensor, 8 is a signal processing circuit, 12 is a matrix circuit, 13 is an encoder, 16 is an inverting circuit, 1
7.71.74 is an analog switch, 68,69°72
．． 73 indicates the volume.

Claims (1)

[Claims] 1) In an image conversion circuit device for a color video camera having a negative/positive inversion circuit, a vertical contour correction circuit and a horizontal contour correction circuit are provided, and the amount of vertical contour correction by the vertical contour correction circuit and the horizontal contour by the horizontal contour correction circuit are An image conversion circuit device characterized in that the amount of correction is configured to be switchable in at least two stages in synchronization with switching of the inverting circuit.