JPH0767154B2 - Imaging device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus such as a video camera, and more particularly to an electronic zoom function for enlarging a captured image.

Conventional technology In order to electronically enlarge an image captured by a conventional image sensor, the output signal of the image sensor is stored in the field memory once, and only the necessary part is read out and processed by interpolation and output. Was. FIG. 8 shows the configuration of a conventional image pickup apparatus of this system.

In FIG. 8, 101 is an image pickup device, 102 is a drive circuit of the image pickup device 101, 103 is a process circuit which generates a luminance signal and a color signal from the output of the image pickup device 101, and 104 is one of the field memories 105 and 106 according to the field. A switch for selecting and writing a signal, a memory control circuit 107 for outputting a write address or a read address of the field memories 105 and 106, and a reference numeral 108 for selecting a field memory 105 or 106 which is not being written and reading a signal according to a field. A selector 109 is an interpolation circuit that performs interpolation, and outputs a signal to the output terminal 110.

FIG. 9 shows a conceptual diagram of image enlargement processing. Now, it is assumed that the image sensor 101 outputs an image of 240 lines in one field. Of these, a case will be described in which a portion corresponding to 180 lines is enlarged and output as a one-screen image as shown in FIG. The magnification in this case is
240/180 = 4/3 times.

In order to increase the number of scanning lines from 180 to 240, the interpolation circuit 109 shown in FIG. 8 performs the interpolation process as shown in FIG. 9 (b). That is, in order to generate a line, the line is read from the field memory 105 or 106, the weight corresponding to the distance is multiplied and added, and the line is interpolated and output. Similarly, the other lines 1 to 3 are interpolated and output from the upper and lower two lines.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, as described above, in the image pickup apparatus having the conventional configuration in which the signal of the entire screen is stored in the field memory and then the necessary portion is read, an enormous amount of memory is required. Had.

In view of the above point, the present invention has an object to provide an image pickup apparatus capable of enlarging an image with a small memory without using a field memory.

Means for Solving the Problems In order to achieve the above object, an image pickup apparatus according to the present invention includes a two-dimensional solid-state image pickup element and a vertical scanning control circuit for controlling start / stop of vertical scanning of the image pickup element in units of one horizontal line. And a horizontal line interpolating circuit for interpolating the horizontal line of the output signal of the solid-state imaging device, and the set of input horizontal lines used for obtaining the output horizontal line by the interpolation calculation by this horizontal line interpolating circuit is one line. The set of input horizontal lines that is the same as the set of input horizontal lines used to obtain the previous output horizontal line or that is used to obtain the next output horizontal line by the interpolation calculation in the horizontal line interpolation circuit is The vertical scan control circuit stops the vertical scan of the solid-state image sensor when the set of input horizontal lines used to obtain the output horizontal line is the same. It is configured to control. More specifically, a solid-state image pickup device having a vertical transfer unit having a shift register structure, an image pickup device driving circuit for controlling transfer / stop of vertical transfer of the solid-state image pickup device by a control signal C1, and the solid-state image pickup device. Output signal of
A switch for allocating S0 to the first line memory M1 to the n-th line memory Mn (n ≧ 3, n is an integer) by the control signal C2, and the m line (2 ≦ m) of the line memories M1 to Mn.
<N, m are integers) selectors for selecting the output signals by the control signal C3, m multipliers for multiplying the output signals S1 to Sm of the selectors by the weighting signals W1 to Wm, and m of the multipliers. An adder for adding output signals, and a control signal generation circuit for outputting the control signals C1, C2, C3, W1 to Wm, and the remaining line memory selected by the selector
The signal stored in Mx (1 ≦ x ≦ n, x is an integer) is
If it is the oldest signal among the line memories M1 to Mn, vertical transfer of the solid-state image pickup device is performed to output a new signal S0new of one line, and the switching unit causes the line memory Mx.
Is selected to control the writing of the signal S0new.

With the above-described configuration, the present invention controls the vertical transfer unit of the solid-state image sensor in the same manner as a conventional field memory,
The image can be enlarged and interpolated with only a small amount of line memory.

EXAMPLES Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of an image pickup apparatus in the first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a solid-state image pickup device, which has a vertical transfer portion having a shift register structure such as a CCD type. Reference numeral 2 denotes a drive circuit of the solid-state image sensor 1, which controls continuous transmission / stop of vertical transfer of the solid-state image sensor 1 by a control signal C1. Further, the control signal C4 is used to sweep out charges from unnecessary scanning lines. Reference numeral 3 is a process circuit for generating a luminance signal, a color signal, a color difference signal, etc. from the output signal of the solid-state image sensor 1. Reference numeral 4 is a switcher for distributing the output signal of the process circuit 3 to the line memories 5 to 7 according to the control signal C2, and 8 is a selector for selecting and outputting two line memories according to the control signal C3. Reference numerals 9 and 10 denote multipliers for multiplying the output signals of the selector 8 by the weight signals W and W2, respectively. The signal of the upper scanning line of the screen is given to the multiplier 9, and the signal of the lower scanning line of the screen is given to the multiplier 10. . An adder 11 adds the output signals of the multipliers 9 and 10 and outputs the result to the output terminal 12. Reference numeral 13 is a control signal generation circuit that supplies a control signal, a weight signal, and an address signal to the line memory.

FIG. 2 shows a block diagram of the control signal generation circuit 13.

Reference numeral 21 is a start address register which indicates the scanning line position at the beginning of the enlarged portion of the screen. Here, the scanning line interval of each field is 1. The integer part is output as the number of unnecessary scanning line sweep-out lines C4, and the decimal part is output to the selector 23. Reference numeral 22 is a pitch register showing a value obtained by converting the scanning line interval of the screen after enlargement into the scanning line interval of the original image, and this value is 1 or less in the case of enlargement. Reference numeral 23 is a selector, which outputs an initial value on the upper side during the vertical blanking period and outputs a signal on the lower side in other cases so that the circuit forms a loop. 24 is a latch circuit, which latches the input once per line. 25 is an adder that adds the output of the latch 24 and the output of the pitch register 22, and outputs the carry signal as C1,
The lower signal is output to the selector 23. A ternary counter 26 counts C1 as a clock input and outputs the count value as C2 and C3. The output of the latch 24 is the weight signal W2
(0≤W2 <1), and the subtracter 27 outputs (1-W-
The result of the subtraction of 2) is the weight signal W1 (0 <W1 ≦ 1)
Is output as.

The operation of the image pickup apparatus having the above-described structure according to this embodiment will be described with reference to FIG.

Now, enlargement in the vertical direction by 4/3 times will be described as shown in FIG. A pitch of 0.67 corresponding to the magnification is written in the pitch register 22 in FIG. The scanning lines output from the solid-state image sensor 1 are stored in the line memories 5 to 7, respectively. First, the interpolation of scanning lines will be described. The latch 24 holds a fractional part of the scanning line in the vertical direction. In order to interpolate the scanning lines, the signals of the upper and lower two scanning lines, that is, and are used. Therefore, the selector 8 functions to output the signal of the line memory 6 to the multiplier 9 and the signal of the line memory 7 to the multiplier 10. Assuming that the value of the fractional part of the vertical address of the scanning line held by the latch 24 is 0.33, the control signal generation circuit 13 outputs 0.67 for W1 and 0 for W2.
33 is output, the multipliers 9 and 10 multiply the scanning lines by the respective weights, and the adders 11 add the weights to interpolate the signals of the scanning lines and output. At this time, the adder 25
Then, the next address is added, and the output of latch 24 is 0.
The value of 0.67 in the pitch register 22 is added to 33. Where the sum is
Since it is 1.00, the carry signal, that is, C1, becomes 1 and is given to the drive circuit 2, and the decimal part 0.00 is written in the latch 24 by the next horizontal pulse HD. When C1 becomes 1, the drive circuit 2 works so as to perform vertical transfer of the solid-state image sensor 1, and the solid-state image sensor 1 outputs a signal of a new scanning line. on the other hand,
The scanning line signals stored in the line memory 5 are
It is the oldest of these and is no longer used to interpolate subsequent scanlines. Therefore, the switch 4 operates to select the line memory 5 and write the signal of the scanning line output from the solid-state image pickup device 1. Reading and writing of these line memories can be performed simultaneously. That is, the scanning lines are written while reading the scanning lines.

Next, the interpolation of scanning lines will be described. Since the content currently held in the latch 24 is 0.00, the scanning line signal may be used as it is. Here, the multiplier 9
The weight signal W1 given to 1 is 1, the weight signal W2 given to the multiplier 10 is 0, and the signal of the scanning line
It operates so that the signal of the scanning line is supplied to 10. That is, the selector 8 outputs the signal of the line memory 7 to the multiplier 9 and the signal of the line memory 5 to the multiplier 10. Therefore, the adder 11 outputs a scanning line, that is, a scanning line signal. At this time, the adder 25 adds the next address, and adds the value 0.67 of the pitch register 22 to the output 0.00 of the latch 24. Here, since the sum is 0.67, the carry signal, that is, C1, becomes 0 and is given by the drive circuit 2, and the fractional part 0.67 is written in the latch 24 by the next horizontal pulse HD.
When C1 becomes 0, the drive circuit 2 does not perform the vertical transfer of the solid-state image sensor 1, so that nothing is output from the solid-state image sensor 1. Therefore, each line memory holds the current contents.

Of the above operations, the selection of reading / writing of the line memory and the control of transfer of the solid-state image sensor are summarized as shown in FIG.

Hereinafter, by repeating the same operation, vertical expansion can be realized only by the line memory.

An example of horizontal expansion will be described. The output of the adder 11 is applied to the horizontal interpolation circuit shown in FIG. 4 by using the output of the control signal generating circuit shown in FIG. 3 as the read address of the line memories 5 to 7, and the control signal shown in FIG. Interpolation between two horizontal pixels may be performed using the horizontal weight signals W3 and W4 generated by the generation circuit.

As described above, in the image pickup apparatus of this embodiment, it is possible to realize an image pickup apparatus having a function of enlarging an image, that is, an electronic zoom function, by using only a few line memories without using a frame memory.

Next, an image pickup apparatus according to another embodiment of the present invention will be described.

FIG. 5 is a block diagram of the image pickup apparatus of this embodiment.

In FIG. 5, only the process processing part is different from FIG. 1, and the other parts are exactly the same. 51 and 52 are 1
1H delay line (1HD
L), 53 and 54 are the input of 1HDL51 and 52 to the control signal generating circuit 13
Selector to switch by control signal C1 output by
This is a signal generation circuit that generates a luminance signal and a color signal by using the output signals of the 1HDL51 / 52 and the output signal of the solid-state imaging device 1. These 51 to 55 form a process processing unit 56.

The operation of the image pickup apparatus of this embodiment configured as described above will be described.

This embodiment operates similarly to the first embodiment. And
When the control signal C1 controls the transfer of the solid-state image pickup device, the selectors 53 and 54 output the signals of the A side, that is, the next scanning line so as to write them to the 1HDL 51 and 52. Conversely, when the control signal C1 is controlled so as to stop the transfer of the solid-state image sensor 1, the selectors 53 and 54 are on the B side, that is, the same 1HDL.
The signal of is output so as to be written again. The process processing unit 56 operating in this way is used as the process circuit 3 in FIG.
Replacing with, the other parts perform exactly the same operation as in the first embodiment, so that
The same effect as that of the first embodiment can be realized also in a signal processing system such as a single-chip camera which has a delay line and generates a luminance signal and a chrominance signal by utilizing the correlation in the vertical direction.

In these embodiments, the case where the number of line memories is 3 and the interpolation is performed using 2 lines in the vertical direction has been described. However, the number of these lines is increased.
Higher-order interpolation is also possible. At this time, the number of line memories may be one or more than the number of scanning lines used for interpolation.

In addition, the control of the read / write of the line memory and the control of the transfer of the solid-state image sensor are not performed at the timing shown in FIG.
Even if the lines are shifted, the effect does not change.

In the second embodiment, the contents of the delay line are held by writing the output of the delay line into the same delay line, but the driving of the delay line may be stopped to hold the contents.

EFFECTS OF THE INVENTION According to the present invention, even when performing a moving image enlargement process such as an electronic zoom, it can be realized with only a few line memories without using a frame memory, and the memory capacity is significantly reduced. Power consumption can be reduced and
Moreover, the configuration is easy.

[Brief description of drawings]

1 is a block diagram of an image pickup apparatus according to the first embodiment of the present invention, FIG. 2 is a block diagram of a control signal generation circuit according to the same embodiment, and FIG. 3 is a horizontal enlargement control signal generation circuit according to the same embodiment. 4 is a block diagram of a horizontal expansion interpolation circuit in the same embodiment, and FIG. 5 is a block diagram of the second embodiment of the present invention.
6 is a block diagram showing the control operation of the first embodiment, FIG. 7 is a state diagram showing the control operation of the second embodiment, and FIG. 8 is a block diagram of the conventional example. 9 and 9 are conceptual diagrams showing the concept of image enlargement processing. 1 ... Solid-state image sensor, 4 ... Switching device, 5-7 ... Line memory, 8 ... Selector, 9,10 ... Multiplier, 11 ... Adder, 13 ... Control signal generating circuit.

Claims (2)

[Claims] 1. A two-dimensional solid-state image pickup device, a vertical scanning control circuit capable of controlling continuation / stop of vertical scanning of the image pickup device in units of one horizontal line, and interpolation of horizontal lines of the output signal of the solid-state image pickup device. And a horizontal line interpolation circuit, and the set of input horizontal lines used to obtain the output horizontal line by the interpolation calculation in this horizontal line interpolation circuit is the input horizontal line used to obtain the output horizontal line one line before. Or the set of input horizontal lines used to obtain the next output horizontal line by the interpolation calculation in the horizontal line interpolation circuit is the same as the set of input horizontal lines used to obtain the current output horizontal line. When there is no change, the vertical scanning control circuit sets the vertical scanning of the solid-state image sensor to 1
An image pickup apparatus, which is controlled to stop in units of horizontal lines. 2. A two-dimensional solid-state image pickup device, a vertical scanning control circuit capable of controlling continuation / stop of vertical scanning of the image pickup device in units of one horizontal line, and a reading for designating a reading position of the solid-state image pickup device. A position designating circuit and a horizontal line interpolating circuit for interpolating a horizontal line of the output signal of the solid-state image sensor are provided, and a set of input horizontal lines used to obtain an output horizontal line by an interpolation calculation in the horizontal line interpolating circuit is provided. , A set of input horizontal lines which is the same as the set of input horizontal lines used to obtain the output horizontal line one line before, or which is used to obtain the next output horizontal line by the interpolation calculation in the horizontal line interpolation circuit However, when the set is the same as the set of input horizontal lines used to obtain the current output horizontal line, the solid-state image sensor drive circuit performs vertical scanning of the solid-state image sensor. Control is performed so that the scanning is stopped in units of horizontal lines, and a signal corresponding to the number of scanning lines that is one less than the integer part of the enlarged leading scanning line position designated by the reading position designating circuit is fed to the leading scanning line of the solid-state image sensor. An imaging apparatus, wherein the solid-state imaging device drive circuit drives the solid-state imaging device so that the start position is swept during a period other than the vertical effective scanning period.