JP2004297300A - Image recording apparatus and electronic camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording apparatus and an electronic camera whereby an on-screen information image is visually recognized to identify the resolution of a recorded image. <P>SOLUTION: A CPU 16 gives a timing signal whose frequency is changed in response to a resolution change command to an image signal generating section 14 and an on-screen display signal generating section 28. The image signal generating section 14 changes the resolution of photographing image data on the basis of the timing signal. The on-screen display signal generating section 28 also changes the resolution of on-screen information image on the basis of the timing signal. A video signal generating section 27 composites the photographing image and the on-screen information image whose resolutions are changed and displays the result on a display means 30. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image recording apparatus and an electronic camera that record by changing the resolution of image data. More specifically, the present invention relates to an image recording apparatus that displays an on-screen information image on a display unit together with an image for recording, and an electronic camera using the same. It is about.
[0002]
[Prior art]
An electronic camera that records still images and moving images as digital data, for example, on a memory card is known. This electronic camera is provided with a display unit such as an LCD for displaying an image captured by the solid-state imaging device. On the display unit, information such as characters and numbers such as “recording”, “recording stop”, and “recording time” is displayed on-screen by an on-screen display (OSD) function (Patent Document 1). .
[0003]
An electronic camera provided with an electronic zoom function is known. The electronic zoom function is a function of electronically enlarging an image captured by a solid-state image sensor in addition to the optical zoom of the zoom lens (Patent Document 2).
[0004]
Furthermore, for the electronic camera, select one of a plurality of predetermined resolutions such as a fine mode which is a high resolution and a normal mode which is a low resolution, for example, as the resolution of the recorded image in the shooting mode. There is something that can be done.
[0005]
[Patent Document 1]
JP-A-10-304400 [Patent Document 2]
JP-A-10-336494 [0006]
[Problems to be solved by the invention]
By the way, the number of pixels at the time of imaging by an electronic camera has been dramatically improved in recent years. However, when the electronic zoom function is used, a part of the image is electronically enlarged, so that the resolution of the recorded image is lowered. In particular, when the display unit is smaller in size due to the miniaturization of the body and the number of displayable pixels is smaller than the number of pixels at the time of imaging, the pixels of the image to be displayed are set horizontally and vertically. Processing to thin out in the direction is performed. As a result, even if the image on the display unit is viewed, the resolution is not noticed, and there is a possibility that an image with a low resolution is recorded.
[0007]
The present invention has been made to solve the above problems, and has been devised so that the resolution of an image to be recorded can be easily visually recognized based on a display image displayed on a display unit. An object is to provide an image recording apparatus and an electronic camera.
[0008]
[Means for Solving the Problems]
To achieve the above object, in the image recording apparatus of the present invention, image signal generating means for generating and outputting recording image data, and on-screen display signal generating means for generating and outputting on-screen information image data, The recording image data generated and the on-screen information image data are combined, and the combined image data is converted into an analog image signal and displayed on a display means, A means for issuing a resolution conversion command in response to an operation for changing the image data to a desired resolution, and selecting any one of a plurality of clock signals having different frequencies based on the resolution conversion command Means for outputting a clock signal to the image signal generating means and the on-screen display signal generating means, respectively, The image signal generating means and the on-screen display signal generating means, in which to output to change each the resolution of the image data based on the selected clock signal.
[0009]
As the means for inputting the same clock signal to the image signal generating means and the on-screen display signal generating means, respectively, there are a clock generating means for generating a plurality of clock signals having different frequencies, and a resolution conversion command of the plurality of clock signals. It is desirable to comprise with the selection means which selects the clock signal based on it.
[0010]
The electronic camera also has an electronic zoom function and a function for changing the resolution of a recorded image. When an image recording apparatus is used in an electronic camera, a resolution conversion command may be output in response to an operation using these functions.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an electrical outline of an electronic camera 10 according to an embodiment of the present invention. The subject image is formed on the imaging surface of the solid-state imaging device (CCD) 12 by the photographing lens 11. The CCD 12 scans the subject image with the operation clock from the timing signal generator 13 and outputs an image pickup signal. The imaging signal is supplied to the image signal generation unit 14 where it is converted into image data composed of digital R, G, and B.
[0012]
A clock pulse output from the oscillator 15 is input to the timing signal generator 13, and a system clock output from another oscillator 17 having a different clock to the transmitter 15 is input to the CPU 16 and the image signal generator 14. Each pulse is input. The CCD 12 and the image signal generator 14 are driven in synchronization with a timing signal output from the timing signal generator 13. This timing signal includes a dot clock pulse, a horizontal synchronizing pulse, and a vertical synchronizing pulse. The timing signal generator 13 is configured so that the timing signal can be appropriately changed by a resolution conversion command from the CPU 16.
[0013]
For example, the horizontal synchronizing signal is divided based on the clock pulse of the transmitter 15 to generate and output a plurality of frequency clock pulses (horizontal synchronizing pulses), and a resolution conversion command from the CPU 16. In response to this, the variable clock generator is configured to include a clock select for selecting and outputting a specific horizontal sync pulse from a plurality of horizontal sync pulses. The vertical sync pulse is generated by frequency division based on the selected horizontal sync pulse. The number of horizontal sync pulses to be generated in response to the resolution conversion command is prepared according to the number of display position information obtained at the time of electronic zoom.
[0014]
Display position information for enlarging and displaying a part of the imaging screen is input to the CPU 16 from the setting means 18 such as a zoom button. The display position information corresponds to the resolution conversion command, and the CPU 16 sends the resolution conversion command to the timing signal generator 13 based on the display position information.
[0015]
The image signal generation unit 14 includes a preprocessing circuit and a resolution conversion circuit 19. The pre-processing circuit extracts an R, G, B color signal from the image signal obtained from the CCD according to a dot clock pulse and a horizontal / vertical synchronization pulse, and outputs an optical black enable signal and an enable signal (correlation). A double sampling circuit 20, an A / D converter 21, and a three-line interpolation circuit that outputs R, G, B digital image data separated into three colors R, G, B according to a CCD filter array 22.
[0016]
The resolution conversion circuit 19 includes a horizontal resolution conversion circuit 23, a data buffer 24, and a vertical resolution conversion circuit 25. The horizontal resolution conversion circuit 23 refers to the pixel data in one horizontal line of each of the R, G, and B image data, and performs enlargement / reduction conversion to a desired pixel data amount designated by the CPU 16. At the time of enlargement conversion, in order to display the image range according to the display position information on the display means, an offset according to the display position information is added to the value of the dot counter that counts up the pixels input at the timing of the dot clock pulse. A desired position is enlarged and displayed.
[0017]
The data buffer 24 temporarily stores the R, G, B image data of each horizontal line converted into a desired amount of image data sequentially for three lines.
[0018]
The vertical resolution conversion circuit 25 refers to a plurality of horizontal line image data, and scales and converts the number of horizontal lines to a desired number of horizontal lines designated by the CPU 16. When this enlargement process is performed, the frequency of the system clock pulse is set earlier than the horizontal synchronization pulse for reading image data from the CCD 12. Accordingly, the CCD 12 and the horizontal resolution conversion circuit 23 are driven based on the horizontal synchronization pulse, and the vertical resolution conversion circuit 25 is driven based on the system clock pulse having a frequency faster than that of the horizontal synchronization pulse. Electronic zoom is possible without changing the frame rate up to a magnification corresponding to the ratio of the frequency to the pulse.
[0019]
The digital image data subjected to the resolution conversion is sent to the YC processing unit 26. The YC processing unit 26 performs processing such as sharpness correction, gamma correction, contrast correction, white balance correction, and conversion into luminance signal Y and chroma signal C on the image data. The processed image data is sent to the video signal generator 27.
[0020]
Further, the electronic camera 10 is provided with an on-screen display (OSD) signal generation unit 28, a display unit 30, a frame memory 31, a recording image processing unit 32, a compression / decompression processing unit 33, a recording / playback processing unit 34, and the like. ing.
[0021]
The CPU 16 is provided with a RAM 35 that is a readable / writable storage means, and a ROM 36 that stores programs and constants for controlling the operation of the CPU 16. Each operation information from the setting means 18 is configured to be transmitted to the CPU 16.
[0022]
The OSD signal generation unit 28 includes a display video memory (not shown), a memory controller that controls the display video memory, and a resolution conversion circuit. The on-screen information image is a character or a number such as “REC” or a tape running count number that is displayed in a synthesized manner with the through image. These fonts are converted into dot data in advance and written in the data ROM 37 ing.
[0023]
The CPU 16 reads out from the data ROM 37 in response to an operation from the setting unit, and supplies the dot method data to the OSD signal generation unit 28. The OSD signal generation unit 28 receives dot method data, and generates a dot signal that constitutes characters or numbers of a predetermined resolution, color, and size based on the dot clock pulse and the horizontal / vertical synchronization pulse. 27. This process is performed so that the size of the on-screen information image displayed on the display unit 30 is always constant regardless of the resolution.
[0024]
The video signal generation unit 27 decodes the synthesized image data obtained by synthesizing the image data and the display image data into an analog signal, a video memory having a storage capacity corresponding to the number of pixels of the display unit 30; And a D / A converter that converts the composite image data into a composite analog signal. The composite image data stored in the video signal generation unit 27 is displayed on the display means 30, for example, the LCD in synchronization with the display clock.
[0025]
A plurality of data buffers 24 are provided. The CPU 16 uses all during live view display, and controls the data buffer 24 to switch the buffer so as to store a part of the buffer as image data for recording in response to the image recording command.
[0026]
The captured image data is simultaneously sent from the A / D converter 21 to the recording image processing unit 32, the three-line interpolation circuit 22, and the data buffer 24. The image data for recording is sent from the data buffer 24 to the frame memory 31. The recording image data stored in the frame memory 31 is sent to the recording image processing unit 32.
[0027]
The recording image processing unit 32 sends the image data for recording to the compression / decompression processing unit 33 after performing calculations for adjusting the exposure and white balance of the image data to be recorded.
[0028]
The compression / decompression processing unit 33 compresses the recording image data by a technique typified by the JPEG format or the TIFF format, or performs processing for expanding / decompressing the compressed data, and then sends it to the recording / reproduction processing unit 34. The recording / playback processing unit 34 converts the data to record or read the compressed image data on the recording medium 38. In this way, image data can be recorded on the recording medium 38 simultaneously with the through image display. The recording medium 38 may be a detachable recording medium represented by a memory card or MO.
[0029]
The operation of the electronic camera 10 configured as described above will be described. As shown in FIG. 2, in the shooting mode, a through image display is performed in which the subject image is always displayed on the LCD. Further, an on-screen information image such as “REC” indicating that recording is in progress or a numerical value of a tape counter is also displayed on the display means 30.
[0030]
The setting means 18 has a wide button and two zoom buttons. In response to these operations, the zoom control unit 40 moves part or all of the photographing lens 11 to change the focal length. When the tele button is operated, the zoom control unit 40 changes the focal length of the photographing lens 11 from the wide end to the tele end.
[0031]
When the tele button is further operated after the photographing lens 11 reaches the tele end, the electronic zoom mechanism is activated. Since the electronic zoom function cuts and enlarges a part of the imaging screen, the resolution of the image is lower than that during optical zoom. In order to reduce the resolution of the image, the frequency of the operation clock is lowered. Therefore, in response to the operation of the tele button after detecting that the taking lens 11 has reached the tele end, the CPU 16 sends a resolution conversion command for instructing a change to reduce the frequency of the horizontal synchronization signal to the timing signal generator 13. .
[0032]
The timing signal generator 13 selects and outputs a specific horizontal synchronization pulse from a plurality of horizontal synchronization pulses each having a different frequency. In addition, a vertical synchronization signal is generated based on the selected horizontal synchronization signal. Timing signals including these horizontal and vertical synchronization signals are sent to the image signal generation unit 14 and the OSD signal generation unit 28, respectively.
[0033]
Further, display position information corresponding to the electronic zoom is sent from the CPU 16 to the image signal generation unit 14. The resolution conversion circuit 19 cuts a part of the image of the digital image data based on the display position information obtained from the CPU 16, and enlarges the image data in the cut range based on the horizontal / vertical synchronization pulse.
[0034]
On the other hand, the OSD signal generation unit 28 generates display image data based on the dot method data obtained from the CPU 16, and enlarges the display image data based on the horizontal / vertical synchronization pulse.
[0035]
The video signal generation unit 27 generates combined image data that has undergone resolution conversion by combining the image data on which the enlargement processing has been performed and the display image data and storing them in a video memory.
[0036]
Thereby, the resolution of the data of the original through image and the on-screen information image is changed to the resolution according to the resolution conversion command and displayed on the display means 30. As a result, as shown in FIG. 3, it is possible to easily determine the roughness of the image, which is difficult to understand simply by visually recognizing the through image, based on the roughness of the on-screen information image. Note that the on-screen information image changes only in the roughness of the image, and the font size is always displayed constant.
[0037]
When reproducing the image recorded on the recording medium, the recording / reproduction processing unit 34 determines the resolution from the data when reading the reproduction image data, and sends the resolution information to the CPU 16. The reproduction image data is transmitted to the compression / decompression processing unit 33 and subjected to decompression processing, and then sent to the image signal generation unit 14.
[0038]
The CPU 16 sends a resolution conversion command to the timing signal generator 13 based on the resolution information. The timing signal generator 13 sends timing signals corresponding to the resolution conversion command to the image signal generation unit 14 and the OSD signal generation unit 28, respectively. Thereby, an on-screen information image having a resolution corresponding to the reproduced image is displayed together with the reproduced image. According to this, the resolution of the recorded image data can be identified by the roughness of the on-screen information image.
[0039]
Also, when the composite signal input from the external input terminal is displayed on the display means 30, the resolution of the external input image data is examined after conversion into a digital signal, and the external input image and the on-screen information image are displayed in accordance with the resolution. If the combined display is performed, the resolution of the external input image can be identified by the roughness of the on-screen information image.
[0040]
In the above embodiment, the OSD signal generation unit 28 receives the horizontal or vertical synchronization pulse and converts the resolution of the dot method data. Instead, on-screen information image (font) data having a different resolution is converted. A plurality of font data may be prepared in advance, and one corresponding to the commanded resolution may be selected and used from the plurality of font data in response to the change of the horizontal or vertical synchronization pulse. According to this, since fonts having different resolutions are stored in advance, font display switching can be performed quickly.
[0041]
In this case, the CPU 16 is configured to send a resolution conversion command to the video signal generation unit 27 as well. As shown in FIG. 4, the video signal generation unit 27 temporarily turns off the display of the on-screen information image on the display unit 30 in response to the resolution conversion command. After the OSD signal generator 28 switches the font and the display data is updated, the display image display unit 30 turns on in response to the update. As a result, the on-screen information image obtained by changing the font of the through image having undergone resolution conversion is updated and displayed on the display means 30.
[0042]
When the video signal generation unit 27 that can perform font switching in synchronization with the change of the supply clock (timing signal) is used, the display means 30 does not disturb the display of the on-screen information image on the display means 30. The procedure for turning OFF and ON the display on the screen can be omitted.
[0043]
Further, as shown in FIG. 5, the data of the on-screen information image may be configured to be enlarged or reduced, that is, resized in synchronization with the change of the timing signal. In this case, only the data of the high-resolution on-screen information image is stored in advance, and the high-resolution data is resized such as a thinning process in response to the resolution conversion command and sent to the OSD signal generation unit 28. What is necessary is just to comprise. According to this, as compared with the above-described embodiment, since only high-resolution data needs to be stored as on-screen information image data, the data ROM 37 having a small capacity can be used.
[0044]
In the above embodiment, the resolution conversion command is output in response to the operation of the electronic zoom. Instead, for example, the resolution of the image data at the time of recording is set to a fine mode (high quality mode) or a normal mode (low). The image quality mode may be performed in response to an operation for changing to the image quality mode. In addition, the present invention is not limited to an electronic camera, and can be applied to an image recording apparatus such as a mobile phone with an electronic camera, a digital video camera, and a video recorder.
[0045]
【The invention's effect】
As described above in detail, according to the present invention, when the resolution of image data to be recorded is changed, the resolution of the on-screen information image data is also changed, so that the roughness of the on-screen information image on the display screen is visually recognized. Thus, the resolution of the recording image data can be reliably identified. In addition, since the same clock signal is input to the image signal generation unit and the on-screen display signal generation unit, the clock generation unit can be shared, and thus low cost can be achieved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an electrical configuration of an electronic camera of the present invention.
FIG. 2 is an explanatory diagram showing a screen of display means at a high resolution.
FIG. 3 is an explanatory diagram showing a screen of display means at a low resolution.
FIG. 4 is a flowchart showing another embodiment for creating an on-screen information image by selecting a font having a resolution corresponding to a resolution conversion command from a plurality of fonts having different resolutions.
FIG. 5 is a flowchart showing another embodiment for generating an on-screen information image by resizing a high-resolution font in response to a resolution conversion command.
[Explanation of symbols]
11 photographing lens 14 image signal generation unit 16 CPU
19 Resolution converter 27 Video signal generator 28 OSD signal generator

Claims (2)

Image signal generating means for generating and outputting recording image data, on-screen display signal generating means for generating and outputting on-screen information image data, and the generated recording image data and on-screen information image data are captured In the image recording apparatus comprising the above-described means for converting the combined image data into an analog image signal and displaying it on the display means,
Means for issuing a resolution conversion command in response to an operation of changing the recording image data to a desired resolution;
Means for selecting any one of a plurality of clock signals having different frequencies based on the resolution conversion command, and outputting the selected clock signals to the image signal generating means and the on-screen display signal generating means, respectively. Prepared,
The image recording apparatus characterized in that the image signal generating means and the on-screen display signal generating means change and output the resolution of each image data based on the selected clock signal. Means for capturing a subject image with a solid-state image sensor and outputting an image signal; image signal generating means for generating and outputting digital image data based on the image signal; and generating and outputting on-screen information image data And an on-screen display signal generating means for capturing and synthesizing and synthesizing the generated recording image data and on-screen information image data, and converting the synthesized image data into an analog image signal and displaying it on the display means. In the electronic camera
Means for issuing a resolution conversion command in response to an operation of changing the image data to a desired resolution;
Means for selecting any one of a plurality of clock signals having different frequencies based on the resolution conversion command, and outputting the selected clock signals to the image signal generating means and the on-screen display signal generating means, respectively. Prepared,
The electronic camera, wherein the image signal generation means and the on-screen display signal generation means change the resolution of the image data based on the selected clock signal and output it.

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