JPH03217178A - Image pickup device to pick up electronically enlarged image - Google Patents

Abstract

PURPOSE:To execute the optimum interpolation of a video signal corresponding to the size of the movement of an object by comparing the video signals read out from a field storing means and a delay means, executing the interpolation based on the video signals read out from the field storing means and the delay means when the size of the movement is smaller than a reference value and executing the interpolation according to the signal from the delay means when the size of the movement is larger than the reference value. CONSTITUTION:An addition/average circuit 21 prepares a signal for even-number field when deciding the movement is small by a subtraction/comparator circuit 24. When it is decided by the subtraction/comparator circuit 24 that the movement of the object is large, while using an FH/2 pulse, either odd-number data or even-number data are selected according to a read field. Thus, when the movement of the object is small, field interpolation is selected while including an average interpolation circuit and when the movement of the object is large, pre-interpolation type line interpolation is selected so that the signal of the preceding line can be inserted as it is.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an imaging device capable of electronically enlarging photography.
In particular, electronically enlarged shooting is possible by dividing the video signal corresponding to the screen into odd and even fields and writing and reading the video signals corresponding to the odd and even fields independently. It relates to an imaging device.

[Prior Art] FIG. 6 is a block diagram for explaining the magnification photographing function of a conventional imaging device capable of electronically magnifying photographing. Referring to FIG. 6, the conventional enlarged photographing unit includes an A/D converter 6 for A/D converting a luminance signal (hereinafter referred to as Y signal);
A field memory 9 for storing the Y signal A/D converted by the A/D converter 6;
A D/A converter 11 for D/A converting the Y signal read out from the D/A converter 11, and an R-Y/B converter for switching the RY signal and B-Y signal, which are color difference signals, based on the MPX signal. -Y
an A/D converter 8 for A/D converting the output signal from the R-Y/BY multiplexer 7, and a field memory 10 for storing the signal from the A/D converter 8. , a D/A converter 12 for D/A converting the R-Y signal among the read signals from the field memory 10, and a D/A converter 12 for D/A converting the B-Y signal among the signals output from the field memory 10. It includes a D/A converter 13 for conversion, and a memory controller 14 for controlling write and read operations of field memories 9 and 10. The field memories 9 and 10 are capable of independently writing and reading video signals, and for example, when enlarging the image by a factor of two, the reading is performed using a clock having half the writing frequency.

FIG. 7 is a schematic diagram for explaining the operation of writing a video signal into the field memory shown in FIG. 6. Referring to FIG. 7, the area 41 to be expanded in the odd field 41
Only a is written to the field memories 9 and 10. Similarly, the expanding portion 42a of the even field 42 is also written into the field memory 9.10. The field memories 9 and 10 to be written are divided into four parts, and a half area of the four divided areas is an expanding part 41a of the odd field 41 and an expanding part 4 of the even field 42, respectively.
2a is written. In this way, conventionally, when enlarging an image, only half of the storage area of the field memory 9.10 is used to store the image.

FIGS. 8A and 8B are schematic diagrams for explaining a conventional method of reading video signals from a field memory. With reference to FIGS. 8A and 8B, first,
The reading method shown in the figure is a reading method in which the same line is output twice, and data written in an odd (even) field is read out in an even (odd) field. 8th
The reading method shown in Figure B is one in which odd field data and even field data are read out alternately line by line.

[Problems to be Solved by the Invention] As described above, the reading method shown in FIG. 8A uses a method of repeatedly outputting the same line twice. With this method, there is no problem when the movement of the subject is large, but when the movement of the subject is small, there is a problem in that the resolution in the vertical direction is greatly degraded. On the other hand, in the readout method shown in Figure 8B, the odd field data and the even field data are read out line by line alternately, so even if the subject movement is small, the vertical resolution is high. It has the advantage that the deterioration is not very large. However, the method shown in FIG. 8B has a problem in that the dynamic resolution deteriorates significantly when the subject moves significantly.

In this way, conventionally, when adopting the readout method shown in FIG. 8A, the problem is that the dynamic resolution when the movement is large is maintained as it is, but the vertical resolution when the movement is small is degraded. If the readout method shown in Figure 8B is adopted, vertical resolution is improved to some extent when the subject moves small, but dynamic resolution deteriorates significantly when the subject moves large. was there.

In other words, conventionally, there is no imaging device capable of electronically enlarging images that can improve the dynamic resolution when the subject is moving a lot, and the vertical resolution when the subject is moving slowly. I didn't.

This invention was made in order to solve the above-mentioned problems, and it is possible to improve the dynamic resolution when the subject moves a lot and to improve the vertical resolution when the subject moves small during enlarged shooting. The object of the present invention is to provide an imaging device capable of electronically enlarging photography.

[Means for Solving the Problems] An imaging device capable of electronically magnifying photography according to the present invention divides video signals corresponding to odd and even fields in the current frame and the immediately preceding frame, respectively, during magnifying photography. a field storage means for storing video signals in a divided storage area; and a field storage means for writing video signals of odd and even fields of one frame into one divided storage area of the field storage means, and writing video signals from the other divided storage area to the other divided storage area. write/read control means for reading video signals of the odd and even fields of the frame; and delay means for delaying the video signals of the odd and even fields of the frame read from the field storage means for a predetermined period. and comparison determination means for subtracting and comparing the video signal read from the field storage means and the video signal delayed by the delay means pixel by pixel and determining whether or not the subtraction result is larger than a predetermined reference value; a first interpolation means for interpolating a video signal corresponding to a screen based on both the video signal read from the field storage means and the signal delayed by the delay means; and the video signal delayed by the delay means. A second interpolation means interpolates a video signal corresponding to the screen, and a comparison determination means selects the output of the first interpolation means in response to the determination that the output is smaller than a predetermined reference value. and interpolation method selection means for selecting the output of the second interpolation means in response to the determination that the output is larger than the reference value.

[Function] In the imaging device capable of electronically enlarging photography according to the present invention,
During enlarged shooting, the video signals corresponding to the odd and even fields of the current frame and the immediately preceding frame are stored in separate storage areas by the field storage means, and the write/read control means stores the video signals corresponding to the odd and even fields of the current frame and the immediately preceding frame. The video signals of the odd and even fields of one frame are written into one of the divided storage areas, and the video signals of the odd and even fields of the other frame are read out from the other divided storage area. video signals of odd and even fields of the frame read from the storage means are delayed by a delay means for a predetermined period;
The video signal read from the field storage means and the video signal delayed by the delay means are subtracted and compared pixel by pixel by the comparing and determining means, and it is determined whether the subtraction result is larger than a predetermined reference value; When the interpolation method selection means determines that the output is smaller than a predetermined reference value by the comparison and determination means, the output of the first interpolation means is selected and delayed by the video signal read from the field storage means and the delay means. The video signal corresponding to the screen is interpolated based on both of the video signals, and the output of the second interpolation means is selected in response to the determination that the video signal is larger than a predetermined reference value. Interpolation of the video signal corresponding to the screen is performed using the video signal delayed by .

That is, the comparison and determination means compares and determines the video signal read out from the field storage means and the delay means, and the interpolation method selection means determines that the video signal is smaller than a predetermined reference value by the comparison and determination means. The first interpolation means is selected and the video signal corresponding to the screen is interpolated based on the read signals from the field storage means and the delay means, and it is determined that the video signal is larger than a predetermined reference value. Accordingly, the second interpolation means is selected and interpolation is performed using the signal from the delay means, so that optimal video signal interpolation is performed according to the magnitude of the movement of the subject.

[Embodiment of the Invention] FIG. 1 is a block diagram for explaining the magnification photographing function of an electronically magnified photographing imaging device according to an embodiment of the present invention. Referring to FIG. 1, the enlarged photographing section of this embodiment includes an A/D converter 6 for A/D converting the Y signal, and an A/D converter 6 for A/D converting the Y signal.
a field memory 9 for storing the Y signal A/D converted by the /D converter 6; a line memory 2 for delaying the Y signal read from the field memory 9 by one horizontal period (hereinafter referred to as IH); A comparison/calculation/interpolation circuit 3 into which the output signal from the field memory 9 and the output signal from the line memory 2 are manually input, and a D/A conversion for D/A converting the output signal from the comparison/calculation/interpolation circuit 3. Vessel 11
and an RY/BY multiplexer 7 for selecting the RY signal and the BY signal based on the MPX signal,
An A/D converter 8 for A/D converting the output signal from the R-Y/11 B-Y multiplexer 7, and a field memory 10 for storing the output signal from the A/D converter 8. , a line memory 4 for IH delaying the output signal from the field memory 10, a comparison/calculation/interpolation circuit 5 into which the output signals from the field memory 10 and the line memory 4 are manually input, and a comparison/calculation/interpolation circuit 5. A D/A converter 12 for D/A converting an output signal corresponding to R-Y among the output signals from the D/A converter 12, and a B-Y signal among the output signals from the comparison/calculation/interpolation circuit 5. A D/A converter 13 for D/A converting the output signal and a field memory 9
and a memory controller 1 for controlling writing and reading of the field memory 10.

FIG. 2 is a block diagram for explaining the configuration of the comparison/calculation/interpolation circuit shown in FIG. 1. Referring to Figure 2,
The comparison/calculation/interpolation circuit includes an averaging circuit 2121 for averaging the output signal from the field memory and the output signal from the line memory, and the output signal from the averaging circuit 21 and the output signal from the field memory. A data selector 22 to which is input, a data selector 23 to which output signals from the field memory and line memory are input, subtract the output signal from the field memory and the output signal from the line memory, and compare it with reference data. a subtraction/comparison circuit 24 for determining whether the difference is greater than or not; and a data selector 25 for selecting either the output signal of the data selector 22 or the output signal of the data selector 23 in response to the output signal of the subtraction/comparison circuit 24. including.

FIG. 3 is a schematic diagram for explaining the write operation to the field memory shown in FIG. 1. Referring to Figure 3,
Writing to field memories 9 and 10 is performed only for the enlarged portion of each field A-D. 4
The fields are written to one field memory plane. The reason why A is placed to the right of B and C is placed to the right of D is to simplify reading. This arrangement is applied in the case of NTSC, and in the case of PAL, B is arranged to the right of A13, and D is arranged to the right of C.

FIG. 4 is a schematic diagram showing the read results of the field memory and line memory read during writing of frame 1 shown in FIG. 3. Referring to FIG. 4, for example, in frame I, after reading the data of the first line of field D, the next IH reads the data of the first line of field C. In this read, both are read at half the frequency of the write clock. Furthermore, since C (A) is placed to the right of D (B) as described above, the row address of the memory can remain the same value during this period. Also, frame I
In this case, writing is performed to A or B, and reading is performed to C or D, so there is no conflict between the writing and reading addresses.

Therefore, there is no gap between images caused by the presence of old data and new data at the same time in the middle of an output video as in the conventional case. Writing and reading of the field memory as described above is controlled by the memory controller 1 shown in FIG. Here, the data read from the 14 field memory is input as is to the line memory and delayed by IH. At this time, the input and output of the line memory are not only delayed by IH, but also shifted by one field.

5A and 5B are schematic diagrams for explaining the interpolation operation by the comparison/calculation/interpolation circuit shown in FIG. 4. FIG.

The interpolation operation will be explained with reference to FIG. 2 and FIGS. 5A and 5B. Here, the comparison/calculation/interpolation circuit shown in FIG. 2 has a function of detecting movement between fields by comparing the input and output of the line memory, and switching between interfield interpolation and interline interpolation. The subtraction/comparison circuit 24 determines whether the difference between the input and output of the line memory is larger or smaller than the reference data. If it is determined to be large, it means that the movement of the subject is large.
If it is determined that the movement is small, it means that the movement of the subject is small. The addition/average circuit 21 creates an even field signal 15 when the subtraction/comparison circuit 24 determines that the movement is small. That is, depending on the field discrimination signal F■, as shown in FIG. 5A, when the number is odd, the field signal is output as is, and when the number is even, the output signal of the addition/averaging circuit 21 is output.

Further, if the subtraction/comparison circuit 24 determines that the movement of the subject is large, the FH/2 pulse is used to select odd data and even data according to the field to be read. In other words, data of C (A) is always output when it is an odd field, and data of D (B) is always output when it is an even field.
) data is always output. Here, the FH/2 pulse is a 2H period pulse that repeats L and H for each IH.

As described above, in this embodiment, when the subject movement is small, interfield interpolation including an average interpolation circuit is selected, and when the subject movement is large, pre-interpolation is selected in which the signal of the previous line is inserted as is. Interpolation between lines of type is selected. Therefore, when the subject is moving little, a smooth video signal that makes full use of the signals from both fields is output, and when the subject is moving significantly, there is no gathering or afterimage caused by the time difference between fields, and the dynamic resolution is improved. Ru.

[Effects of the Invention] As described above, according to the present invention, the comparison and determination means compare and determine the video signals read out from the field storage means and the delay means, and the interpolation method selection means selects the video signals predetermined by the comparison and determination means. In response to the determination that the video signal is smaller than the reference value set, the first interpolation means is selected and the video signal corresponding to the screen is interpolated based on the video signal read out from the field storage means and the delay means. The second interpolation means is selected in response to the determination that the signal is larger than the reference value, and interpolation is performed using the signal from the delay means. Therefore, during enlarged photography, it is possible to improve the dynamic resolution when the subject is moving a lot, and it is also possible to improve the vertical resolution when the subject is moving little.

[Brief explanation of drawings]

17? 1 is a block diagram for explaining the magnification photographing function of an imaging device capable of electronically magnifying photograph; FIG. 2 is a block diagram for explaining the configuration of the comparison/calculation/interpolation circuit shown in FIG. 1; FIG. 3 is a schematic diagram for explaining the write operation to the field memory shown in FIG. 1, and FIG. 4 is a schematic diagram for explaining the write operation to the field memory shown in FIG. A schematic diagram showing the readout results, Figures 5A and 5B are schematic diagrams for explaining the interpolation operation by the comparison/calculation/interpolation circuit shown in Figure 4, and Figure 6 is a conventional electronically enlarged photographic diagram. FIG. 7 is a schematic diagram for explaining the operation of writing a video signal into the field memory shown in FIG. 6, FIGS. 8A and 8B. 6 is a schematic diagram for explaining a method for reading out a video signal from the field memory shown in FIG. 6. FIG. In the figure, 1 is a memory controller, 2 and 4 are line memories, 3 and 5 are comparison/operation/interpolation circuits, and 21 is an addition/interpolation circuit.
22 is a data selector, 18 and 23 are data selectors, 24 is a subtraction/comparison circuit, and 25 is a data selector. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] An electronic method for performing enlarged shooting by dividing a video signal corresponding to a screen into an odd field and an even field and independently writing and reading the video signal corresponding to the odd field and even field. An imaging device capable of magnification photography, comprising field storage for storing video signals corresponding to respective odd and even fields in the current frame and the immediately preceding frame in separate storage areas during magnification photography. means for writing the video signals of the odd and even fields of one frame into one of the divided storage areas of the field storage means, and writing the video signals of the odd and even fields of the other frame from the other divided storage area; write/read control means for reading video signals of the field storage means; delay means for delaying the video signals of the odd and even fields of the read frame from the field storage means for a predetermined period; and the field storage means. a comparison determination means for subtracting and comparing the video signal read out from the video signal and the video signal delayed by the delay means pixel by pixel and determining whether or not the subtraction result is larger than a predetermined reference value; and the field storage. a first interpolation means for interpolating a video signal corresponding to the screen based on both the video signal read from the means and the signal delayed by the delay means; a second interpolation means for interpolating a video signal corresponding to a screen; and a second interpolation means for selecting an output of the first interpolation means in response to the comparison determination means determining that the output is smaller than the predetermined reference value. and interpolation method selection means for selecting the output of the second interpolation means in response to the determination that the output is larger than the predetermined reference value.