JP2005333186A - Digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital camera capable of realizing suppression of the total amount of images, reproduction of an overwrite image, and easy restoration of an original image. <P>SOLUTION: Main image data of a field to be photographed captured by an image sensor 14 with a camera mode are secured in a main image area 24m of an SDRAM 24. A CPU 30 extracts partial image data belonging to a date area of the main image data, writes character data expressing the date in the date area of the main image data, and prepares reference coordinate data indicating a reference coordinate value of the date area. An image file including the partial image data, the main image data, and the reference coordinate data is prepared in a recording medium 38. At first, the main image data with a character is read out to the main image area 24m and a reproduced image based on the main image data with a character is displayed on an LCD monitor 28 in a reproduction mode. When date deletion operation is executed, the partial image data are synthesized in the date area of the main image data and the date are deleted from the reproduced image. Consequently, it is possible to realize the suppression of the total amount of images, the reproduction of an overwrite image without a special function, and the easy restoration of an original image. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a digital camera, and more particularly to a digital camera having a function of embedding a date in a captured image.

An example of a conventional digital camera of this type is disclosed in Patent Document 1. According to this prior art, the photographed original image and the handwritten input image are separately recorded on the recording medium. As a result, either the overwrite image obtained by overwriting the handwritten input image on the original image or the original image can be selectively reproduced.
Japanese Patent No. 3177474 [H04N 5/91, 5/225, 5/765, 5/781]

    However, in the prior art, since the original image and the handwritten input image are separately recorded on the recording medium, the overwritten image cannot be reproduced by a digital camera having no overwriting function. On the other hand, if an overwrite image is created separately from the original image, the overwrite image can be reproduced even by a digital camera having no overwrite function, but there is a problem that the total amount of images increases. Furthermore, if only the overwritten image is recorded, the total amount of images can be suppressed, but the original image cannot be restored.

    Therefore, a main object of the present invention is to provide a digital camera capable of suppressing the total amount of images, reproducing an overwritten image, and easily restoring the original image.

  According to a first aspect of the present invention, there is provided a digital camera including an imaging unit that captures a scene, an extraction unit that extracts a partial image from a predetermined part of the scene image captured by the imaging unit, and a predetermined image of the scene image. Overwriting means for creating an overwritten image overwritten on the part after extraction processing by the extracting means, creating means for creating position specifying information for specifying the position of the predetermined part, and position when an erasing operation for erasing an arbitrary image is received Synthesis means for synthesizing a partial image with a predetermined portion of the overwritten image based on the specific information is provided.

  The extraction unit extracts a partial image from a predetermined portion of the object scene image captured by the imaging unit. The overwriting means creates an overwritten image in which an arbitrary image is overwritten on a predetermined portion of the object scene image after the extraction processing by the extracting means. The creating means creates position specifying information that can specify the position of the predetermined portion. When the synthesizer receives an erasing operation for erasing an arbitrary image, the synthesizer synthesizes the partial image with the predetermined portion of the overwritten image based on the position specifying information.

  By extracting partial images, the total amount of images can be suppressed. Further, by creating an overwrite image, the overwrite image can be reproduced without preparing a special function. Furthermore, the original image can be restored by combining the partial image with the overwritten image.

  A digital camera according to a second aspect of the present invention is dependent on the first aspect, and further comprises compression means for compressing at least the overwrite image of the partial image and the overwrite image. The total amount of images can be further suppressed by the compression process.

  A digital camera according to a third aspect of the invention is dependent on the second aspect, wherein the compression means performs compression processing with a pixel block having a predetermined vertical size as a unit, and the vertical size of the predetermined portion is an integral multiple of the predetermined vertical size. . Thereby, it is possible to prevent the boundary line between the overwritten image and the partial image from being noticeable.

  A digital camera according to the invention of claim 4 is dependent on claim 2 or 3, and the compression processing includes DCT processing.

  A digital camera according to a fifth aspect of the invention is dependent on any one of the first to fourth aspects, and the arbitrary image includes date information indicating a date and time when the object scene image is captured.

  A digital camera according to the invention of claim 6 is dependent on any one of claims 1 to 5 and is a recording means for recording an image file including a partial image, an overwritten image and position specifying information on a recording medium, and recorded on the recording medium Reproducing means for reproducing a desired image file and receiving means for accepting an erasing operation when the desired image file includes a partial image are further provided.

  An image processing program according to a seventh aspect of the invention is an image processing program executed by a processor of a digital camera, wherein an extraction step of extracting a partial image from a predetermined portion of a scene image captured by an imaging means, an arbitrary step An overwrite step for creating an overwritten image in which an image is overwritten on a predetermined part of the object scene image after the extraction process in the extraction step, a creation step for creating position specifying information for specifying the position of the predetermined part, and erasing an arbitrary image And a synthesizing step of synthesizing the partial image with the predetermined portion of the overwritten image based on the position specifying information when the erasing operation is received.

  According to this invention, the total amount of images can be suppressed by extracting partial images. Further, by creating an overwrite image, the overwrite image can be reproduced without preparing a special function. Furthermore, the original image can be restored by combining the partial image with the overwritten image.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

  Referring to FIG. 1, a digital camera 10 of this embodiment includes an optical lens 12. The optical image of the object scene is irradiated onto the imaging surface of the image sensor 14 through the optical lens 12. On the imaging surface, a charge corresponding to the object scene image, that is, a raw image signal is generated by photoelectric conversion.

  When the camera mode is selected by the key input device 42, a corresponding status signal is given from the system controller 40 to the CPU 30. The CPU 30 instructs the TG 18 to repeat the pre-exposure and thinning-out readout, and gives processing instructions to the signal processing circuit 20 and the video encoder 26 in order to execute through image processing.

  The TG 18 performs pre-exposure to the image sensor 14 in response to a vertical synchronization signal generated at a rate of once every 1/30 seconds, and the raw image signal obtained by this pre-exposure is thinned out. Read from. The read raw image signal of each frame is subjected to a series of processes of noise removal, gain adjustment, and A / D conversion by the CDS / AGC / AD circuit 16. As a result, the raw image data as a digital signal is output from the CDS / AGC / AD circuit 16 at a rate of one frame per 1/30 second.

  The signal processing circuit 20 performs signal processing such as color separation, white balance adjustment, and YUV conversion on the raw image data, and outputs YUV format image data. The output image data is written into the SDRAM 24 through the memory control circuit 22.

  The video encoder 26 reads the image data stored in the SDRAM 24 every 1/30 seconds from the SDRAM 24 through the memory control circuit 22 and encodes the read image data into an NTSC composite video signal. The encoded composite video signal is supplied to the LCD monitor 28, whereby a real-time moving image of the object scene, that is, a through image is displayed on the screen.

  When a recording operation is performed by the key input device 42, a corresponding status signal is given from the system controller 40 to the CPU 30. The CPU 30 instructs the TG 18 to perform one main exposure and one full pixel readout. The TG 18 performs a main exposure on the image sensor 18 and reads a raw image signal obtained by the main exposure from the image sensor 18 in an all-pixel reading mode. The read high-resolution raw image signal is converted into YUV format image data in the same manner as described above. The converted high-resolution image data, that is, main image data is written into the main image area 24 m of the SDRAM 24 through the memory control circuit 22.

  For example, main image data MIM shown in FIG. 2 is secured in the main image area 24m. A date area DT is assigned to the lower end of the main image data MIM. The lower edge of the date area DT coincides with the lower edge of the main image data MIM. The size and position of the date area DT depends on the resolution of the main image data MIM. If the resolution of the main image data MIM is VGA (= vertical 640 pixels × horizontal 480 pixels), the size of the date area DT is 48 pixels × horizontal 480 pixels.

  Note that the vertical size of the date area DT takes into account that the compression processing described later is performed in units of pixel blocks of 8 vertical pixels × 8 horizontal pixels according to the JPEG method. That is, the vertical size of the date area DT is an integral multiple of the vertical size of the pixel block.

  After the main image data based on the main exposure is stored in the main image area 24m, the CPU 30 accesses the SDRAM 24 through the memory control circuit 22 to transfer the partial image data corresponding to the date area from the main image area 24m to the partial image area. Copy to 24p. When copying is completed, a compression command directed to the partial image data is given to the JPEG codec 32. The JPEG codec 32 reads partial image data from the partial image area 24p of the SDRAM 24 through the memory control circuit 22, performs JPEG compression (DCT, quantization, entropy coding) on the read partial image data, and then compresses the compressed partial image. Data is written to the same partial image area 24p through the memory control circuit 22.

  In the example of FIG. 2, the partial image data PIM of vertical 48 pixels × horizontal 480 pixels existing at the lower end of the main image data MIM is copied to the partial image area 24p. The copied partial image data PIM is subjected to JPEG compression. As a result, the compressed partial image data CPIM is secured in the partial image area 24p.

  Subsequently, the CPU 30 acquires today's date from the clock circuit 44 and writes character data indicating the acquired date in the date area of the main image data. When the writing is completed, the CPU 30 gives a compression instruction directed to the main image data to the JPEG codec 32. The JPEG codec 32 executes the same processing as described above, and as a result, the compressed main image data is secured in the main image area 24m.

  In the example of FIG. 2, the character data “2002.10.17” indicating the date is written in the date area DT of the main image data MIM. The main image data MIM having the date is subjected to JPEG compression, and as a result, the compressed main image data CMIM is secured in the main image area 24m.

  When the creation of the compressed partial image data and the compressed main image data is completed, the CPU 30 reads the compressed partial image data from the partial image area 24p through the memory control circuit 22, and obtains the reference coordinate data indicating the reference coordinates (upper left coordinates) of the date area. Tag data that is created by itself and includes the read compressed partial image data and the created reference coordinate data is recorded on the recording medium 38.

  The CPU 30 further reads out the compressed main image data from the main image area 24 m through the memory control circuit 22 and records the read compressed main image data on the recording medium 38. The compressed main image data is recorded at a position following the tag data, thereby completing the image file.

  In the example of FIG. 2, the compressed main image data CMIM is recorded following the tag data TAG, whereby an image file FL is obtained in the recording medium 38.

  The recording medium 38 is detachable, and can be accessed through the I / F 36 when it is mounted in a slot (not shown).

  When the reproduction mode is selected by the key input device 42, a corresponding status signal is given from the system controller 40 to the CPU 30. The CPU 30 gives a processing instruction to the video encoder 26 and reads the compressed main image data from a desired image file recorded on the recording medium 38. The compressed main image data is written into the main image area 24 m of the SDRAM 24 through the I / F 36 and the memory control circuit 22.

  Next, the CPU 30 gives a decompression instruction directed to the compressed main image data to the JPEG codec 32. The JPEG codec 32 reads compressed main image data from the main image area 24m through the memory control circuit 22, performs JPEG decompression (entropy decoding, inverse quantization, IDCT) on the read compressed main image data, and decompresses the main image data. The image data is written into the main image area 24m through the memory control circuit 22.

  The video encoder 26 reads the decompressed main image data stored in the main image area 24m through the memory control circuit 22, performs a reduction zoom and encoding process on the read decompressed main image data, and obtains a low-resolution image obtained thereby. A composite video signal is supplied to the LCD monitor 28. As a result, the reproduced image is displayed on the screen.

  When the image file FL shown in FIG. 3 is reproduced, first, the compressed main image data CMIM is transferred to the main image area 24 m of the SDRAM 24. The transferred compressed main image data is subjected to JPEG expansion, and the expanded main image data MIM is given to the video encoder 26 via the main image area 24m. As a result, the main image with the date written in the lower right is output from the LCD monitor 28.

  When a date deletion operation is performed by the key input device 42 in this state, a corresponding status signal is given from the system controller 40 to the CPU 30. The CPU 30 reads the compressed partial image data and the reference coordinate data from a desired image file. The compressed partial image data is written into the partial image area 24 p of the SDRAM 24 through the I / F 36 and the memory control circuit 22.

  Subsequently, the CPU 30 instructs the JPEG codec 32 to perform a decompression instruction directed to the compressed partial image data. The decompression command includes a coordinate value indicated by the read reference coordinate data. The JPEG codec 32 reads the compressed partial image data from the partial image area 24p through the memory control circuit 22, performs JPEG decompression on the read compressed partial image data, and passes the decompressed partial image data through the memory control circuit 22. Write to image area 24m.

  The write start address of the decompressed partial image data is determined based on the coordinate value included in the decompression command. The partial image data is overwritten on the date area of the main image data. The video encoder 28 repeatedly executes the same processing as described above. As a result, the date is deleted from the main image displayed on the LCD monitor 28.

  When a recording operation is performed here, the main image data from which the date has been deleted is subjected to JPEG compression, and an image file including the compressed main image data obtained thereby is recorded on the recording medium 38.

  The CPU 30 executes processing according to the flowchart shown in FIG. 4 when the camera mode is selected, and executes processing according to the flowcharts shown in FIGS. 5 to 6 when the playback mode is selected. The control program corresponding to these flowcharts is stored in the flash memory 34.

  First, referring to FIG. 4, through image processing is executed in step S1. As a result, a through image is displayed on the LCD monitor 28. When the recording operation is performed, YES is determined in step S3, and the main exposure process is executed in step S5. Specifically, the TG 18 is instructed to perform one main exposure and one full pixel readout. As a result, a high-resolution raw image signal is output from the image sensor 14 and the corresponding main image data is written in the main image area 24 m of the SDRAM 24.

  However, two frame periods are required from the execution of the main exposure process until the main image data is written in the main image area 24m. For this reason, it waits for 2 frame periods in step S7.

  When two frame periods have elapsed, the process proceeds from step S7 to step S9, and the partial image data belonging to the date area of the main image data is copied to the partial image area 24p. In step S11, a compression instruction directed to the copied partial image data is given to the JPEG codec 32. The partial image data is compressed by the JPEG codec 32, and the compressed partial image data obtained thereby is written in the partial image area 24m.

  In step S13, today's date is detected from the clock circuit 44, and character data representing the detected date is written in the main image area 24m. The character data is overwritten in the date area of the main image data. When the overwriting is completed, the JPEG codec 32 is commanded to compress the main image data in step S15. The main image data in which the date is written is compressed by the JPEG codec 32, and the compressed main image data is written in the main image area 24m.

  In step S17, the compressed partial image data is read from the partial image area 24p, the reference coordinate data is created by itself, and tag data including the read compressed partial image data and the created reference coordinate data is stored in the recording medium 38. Record. In step S19, the compressed main image data is read from the main image area 24m, and the read compressed main image data is recorded at a position subsequent to the tag data recorded in step S17. Thereby, the image file is completed. When the process of step S19 is completed, the process returns to step S1.

  Referring to FIG. 5, in step S21, the video encoder 26 is activated, in step S23, the file number N is set to an initial value, and in step S25, compressed main image data is read from the Nth image file. The compressed main image data is written into the main image area 24m through the memory control circuit 22. In step S27, the decompression command directed to the compressed main image data is given to the JPEG codec 32. The compressed main image data is expanded by the JPEG codec 32, and the expanded main image data is written in the main image area 24m. The main image data stored in the main image area 24m is read by the video encoder 26, and as a result, the reproduced image is displayed on the LCD monitor 28.

  In step S29, it is determined whether or not the tag data of the Nth image file includes partial image data. If “NO” here, the presence / absence of an image update operation is determined in a step S31. When an image update operation is performed by the key input device 42, the file number N is updated in step S33, and the process returns to step S25. As a result, the reproduced image displayed on the LCD monitor 28 is updated.

  If YES is determined in the step S29, the presence / absence of a date erasing operation is determined in a step S35, and the presence / absence of an image update operation is determined in a step S37. If “YES” in the step S37, the file number N is updated in a step S39, and then the process returns to the step S25.

  If “YES” in the step S35, the process proceeds to a step S41, and the compressed partial image data and the reference coordinate data are read from the Nth image file. The compressed partial image data is written in the partial image area 24p of the SDRAM 24. In step S43, a decompression command including the coordinate value indicated by the reference coordinate data is given to the JPEG codec 32.

  The compressed partial image data is decompressed by the JPEG codec 32. The expanded partial image data is combined with the date area of the main image data stored in the main image area 24m according to the coordinate value included in the expansion command. The synthesized main image data is read out by the video encoder 26. As a result, the date is deleted from the reproduced image displayed on the LCD monitor 28.

  In step S45, the presence / absence of a recording operation is determined. In step S47, the presence / absence of an image update operation is determined. If YES is determined in the step S47, the file number N is updated in a step S49, and then the process returns to the step S25.

  If YES is determined in the step S45, the same processes as the above-described steps S15 to S19 are executed in steps S51 to S55. As a result, an image file having no partial image data is created in the recording medium 38. When the process of step S55 is completed, the process returns to step S25.

  As can be seen from the above description, the main image data of the object scene captured by the image sensor 14 in the camera mode is secured in the main image area 24 m of the SDRAM 24. The CPU 30 extracts partial image data belonging to the date area of the main image data (S9, S11), writes character data representing the date in the date area of the main image data (S13), and sets the reference coordinate value of the date area. The reference coordinate data shown is created (S17). On the recording medium 38, an image file including partial image data, character-added main image data, and reference coordinate data is created.

  In the reproduction mode, character-added main image data is first read into the main image area 24m of the SDRAM 24, and a reproduction image based on the character-added main image data is displayed on the LCD monitor 28 (S25, S27). When the date erasing operation is performed here, the partial image data is combined with the date area of the main image data (S41, S43). As a result, the date is deleted from the reproduced image displayed on the LCD monitor 28.

  By extracting partial images, the total amount of images can be suppressed. Further, by creating an overwrite image, the overwrite image can be reproduced without preparing a special function. Furthermore, the original image can be restored by combining the partial image with the overwritten image.

  In this embodiment, the partial image data is temporarily copied from the main image area 24m to the partial image area 24p, and then the partial image data is given to the JPEG codec 32 from the partial image area 24p. However, the copying process may be omitted, and the partial image data may be directly supplied to the JPEG codec 32 from the main image area 24m.

  In this embodiment, the image data corresponding to the entire image of the object scene is only the main image data. However, in addition to this, thumbnail image data may be created. In this case, the date writing process and the date erasing process similar to the main image data are executed for the thumbnail image data.

  Further, in this embodiment, reference coordinate data is created in order to specify the position of the date area. However, the date area is uniquely determined according to the resolution of the main image data. Therefore, instead of the reference coordinate data, resolution data indicating the resolution of the main image data may be created, and the position of the date area may be specified based on the resolution data.

It is a block diagram which shows one Example of this invention. It is an illustration figure which shows a part of operation | movement of FIG. 1 Example in camera mode. It is an illustration figure which shows a part of operation | movement of FIG. 1 Example in reproduction | regeneration mode. It is a flowchart which shows a part of operation | movement of FIG. 1 Example in camera mode. It is a flowchart which shows a part of operation | movement of FIG. 1 Example in reproduction | regeneration mode. It is a flowchart which shows a part of other operation | movement of FIG. 1 Example in reproduction | regeneration mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Digital camera 14 ... Image sensor 24 ... SDRAM
28 ... LCD monitor 30 ... CPU
32 ... JPEG codec 34 ... Flash memory 38 ... Recording medium

Claims (7)

Imaging means for capturing the object scene,
Extraction means for extracting a partial image from a predetermined portion of the object scene image captured by the imaging means;
Overwriting means for creating an overwritten image in which an arbitrary image is overwritten on the predetermined portion of the object scene image after extraction processing by the extracting means;
Creating means for creating position specifying information capable of specifying the position of the predetermined portion; and when receiving an erasing operation for deleting the arbitrary image, the partial image is added to the predetermined portion of the overwritten image based on the position specifying information. A digital camera provided with combining means for combining.   The digital camera according to claim 1, further comprising compression means for compressing at least the overwrite image of the partial image and the overwrite image. The compression means performs compression processing with a pixel block having a predetermined vertical size as one unit,
The digital camera according to claim 2, wherein a vertical size of the predetermined portion is an integral multiple of the predetermined vertical size.   The digital camera according to claim 2, wherein the compression processing includes DCT processing.   The digital camera according to claim 1, wherein the arbitrary image includes date information indicating a date and time when the object scene image is captured. A recording means for recording an image file including the partial image, the overwrite image, and the position specifying information on a recording medium;
6. The reproducing apparatus according to claim 1, further comprising: a reproducing unit that reproduces a desired image file recorded on the recording medium; and a receiving unit that receives the erasing operation when the desired image file includes the partial image. The digital camera described. An image processing program executed by a digital camera processor,
An extraction step of extracting a partial image from a predetermined portion of the object scene image captured by the imaging means;
An overwriting step of creating an overwritten image in which an arbitrary image is overwritten on the predetermined portion of the object scene image after the extraction processing by the extraction step;
A creation step for creating position specifying information capable of specifying the position of the predetermined portion; and when an erasing operation for deleting the arbitrary image is received, the partial image is added to the predetermined portion of the overwritten image based on the position specifying information. An image processing program comprising a combining step for combining.

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