JP2002010209A - Digital camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide transformation means being free from the reduction of image data and the degradation of image quality, and recognition means before the transformation if it is possible to acquire a sufficient storage capacity by the transformation, when performing the transformation of reducing an amount of data from the data stored in the digital camera. SOLUTION: The transformation means 3 reduces the resolution of an arbitrary range of data within the image data stored by the storage means 5, a number of colors, a number of frames for a moving image, and then an amount of data. Also, the transformation means 3 reduces an amount of data by re- compressing at the compression ratio higher than a compression ratio in storing the voice data stored by storage means 5. Also, the transformation means 3 operates and indicates the amount of image data and voice data, which are enabled to store after the transformation, before the transformation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera, and more particularly, to a digital camera capable of reducing a data amount by converting resolution, compression ratio, and the like of data recorded on a recording medium in the digital camera.

[0002]

2. Description of the Related Art A digital camera is usually provided with a plurality of photographing modes. For example, the Sanyo DSC-SX150 has a resolution of 1360 x 1024 pixels and 64
Two types of 0 × 480 pixels are provided, and three types of compression ratios of low compression, medium compression and non-compression are prepared, and the user can arbitrarily select a combination of these. Since the data amount per still image is determined by the resolution and the compression ratio, the number of shootable images depends on the selected shooting mode. Specifically, the higher the resolution, the smaller the number of shootable images, and the lower the number, the larger the number. Also, the lower the compression ratio, the smaller the number of images that can be shot, and the higher the compression ratio, the larger the number. Further, the smaller the number of images that can be taken, that is, the larger the amount of data per still image, the more precise images can be taken.

[0003] The photographing mode is selected before photographing. Therefore, the user estimates the necessary resolution and compression ratio and the number of images to be shot, and selects an appropriate shooting mode. Normally, the better the image, the better.
It seems that the user selects the upper limit shooting mode in which the expected number of images can be shot. However, it is impossible to accurately predict the number of images to be taken. If it is less than expected, you should have been able to shoot a better image, and if it is more than expected, you will miss a valuable photo opportunity.

As a technique for solving such a problem, there is a technique for changing the compression ratio of image data recorded on a recording medium in a digital camera (Japanese Patent Laid-Open No. 10-56612). According to this technique, image data captured in a recording mode with a relatively high image quality and a large amount of information is converted into image data with a relatively low image quality and a small amount of information, thereby being recorded on a recording medium. It is possible to increase the number of recordable images by reducing the data amount. Also, there is a technique for changing the resolution or compression ratio of image data (Japanese Patent Laid-Open No. 11-191879). According to this technique, an image can be efficiently recorded in a memory by performing a conversion process that reduces the data size of image data based on incidental information input for each image data.

[0005]

In the prior art as described above, resolution conversion and recompression used as conversion means for reducing the amount of image data recorded in a digital camera are performed on the entire image data. Is accompanied by image quality reduction or size reduction. However, there may be a case where only a part of the area in the image data frame is necessary and the other part may be deleted. For example, when lowering the resolution of a group photo of a person, whether the method of reducing the entire image data or the method of cutting out the area including the part where the person is effective is effective depending on the necessity of the background Although it is expected that the data will differ from one data to another, the prior art only provides a method for reducing the entire image data.

In recent years, digital cameras that can record not only conventional still images but also moving images and sounds have appeared. In these, not only image data,
Audio data conversion processing is also effective.

Further, when selecting image data or audio data to be subjected to the data conversion processing, how many data amounts that can be newly recorded by the data conversion processing correspond to, for example, a still image? Such information is required. However, still images, audio, still images with audio,
When various types of data such as moving images are recorded together, it is impossible for the operator to calculate the above information.

[0008]

The invention according to claim 1 is
Recording means for recording data, data designating means for designating predetermined data from data recorded by the recording means, and conversion means for performing conversion for reducing the data amount of data designated by the data designating means It is characterized by having.

According to a second aspect of the present invention, in the digital camera according to the first aspect, the data comprises image data and audio data.

According to a third aspect of the present invention, in the digital camera according to the second aspect, the image data includes a still image and a moving image.

According to a fourth aspect of the present invention, in the digital camera according to any one of the first to third aspects, the converting means reduces the data size by performing color reduction upon image compression. And

According to a fifth aspect of the present invention, in the digital camera according to any one of the first to third aspects, when the moving image is compressed, the data size is reduced by dropping frames. And

According to a sixth aspect of the present invention, in the digital camera according to any one of the first to third aspects, the conversion means cuts an arbitrary range in the image data frame to lower the resolution. And

According to a seventh aspect of the present invention, in the digital camera according to any one of the first to third aspects, the conversion means reduces a data amount by increasing a compression rate of audio data. I do.

According to an eighth aspect of the present invention, in the digital camera according to any one of the first to third aspects, the amount of image data and audio data which can be recorded before and after the conversion by the conversion means. Is calculated and displayed.

According to a ninth aspect of the present invention, in the digital camera according to any one of the first to third aspects, the conversion means dynamically determines a compression rate according to a remaining memory free space. Features.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic configuration diagram of a digital camera according to the present invention.

Reference numeral 1 denotes an image pickup means having an image sensor for picking up an image of a subject, and specifically corresponds to a camera.
Reference numeral 2 denotes recording means for recording voice, and specifically corresponds to a microphone. Reference numeral 3 denotes a conversion unit that performs conversion according to the specified recording mode on the data taken in by the imaging unit 1 and the recording unit 2. Reference numeral 4 denotes a recording mode specifying unit that specifies the recording mode. Reference numeral 5 denotes a recording unit that records the data generated by the conversion unit 3, and 6 denotes a data designation unit that designates predetermined data from the data recorded in the recording unit 5. In the normal processing of the digital camera, the image data and the audio data captured by the imaging means 1 and the recording means 2 are converted by the conversion means 3 according to the recording mode designated by the recording mode designation means 4, and the recording means 5 Will be recorded. FIG. 2 is a diagram illustrating an example of the recording mode. A digital camera usually has a plurality of recording modes as shown in FIG.

FIG. 3 is a diagram showing a procedure of an embodiment according to the present invention.

First, in step 7, data to be converted is selected from the data recorded in the recording means 5 by the data designating means 6. Next, at step 8, the recording mode after conversion of the data selected at step 7 is selected from the plurality of recording modes as shown in FIG. In this case, it is desirable that a recording mode selectable in step 8 be displayed in accordance with the recording mode before conversion of the data selected in step 7.

In step 9, the data amount of the data selected in step 7 after conversion is calculated, compared with the data amount before conversion, and the number or time of images or sounds that can be recorded after conversion is displayed. In step 10, it is confirmed whether to execute the conversion, stop the conversion, or perform additional selection of other data based on the recordable number or recordable time displayed in step 9. Step 10
When the addition is selected, the process returns to step 7. Therefore, a plurality of data can be selected by selecting the addition in step 10 and repeating the processing in steps 7 to 9. If the stop of the conversion is selected in step 10, the process ends without performing the data conversion. When the execution of the conversion is selected in step 10, the conversion of all the data selected in step 7 is performed by the conversion unit 3 in step 11, and the converted data is recorded in the recording unit 5 in step 12. .

FIG. 4 is a diagram showing the procedure of an embodiment relating to the conversion of image data in step 11 of FIG.
First, in step 13, the image data is expanded. If the resolution needs to be converted, the resolution of the image data obtained in step 13 is converted in step 15. As a resolution conversion method, for example, a method of thinning out data in an image data frame according to the resolution after conversion can be considered. If the resolution of the image data frame before conversion is
If the resolution after the conversion is 1280 × 960 pixels and the resolution after the conversion is 640 × 480 pixels, data is deleted every other pixel both vertically and horizontally. By this resolution conversion method, the image data frame of FIG. 5B can be obtained from the image data frame of FIG.

Further, as shown in FIG. 5C, an image data frame corresponding to the resolution after conversion is cut out from an arbitrary position in the image data frame before conversion, and this is called an image data frame after conversion. A method is conceivable. FIG. 6 is a diagram showing an embodiment relating to partial designation of a cutout range of an image data frame. When clipping from an image data frame is selected as the resolution conversion method, an image data frame before conversion and a frame 19 indicating a range to be clipped are displayed on an LCD (liquid crystal display) 18 provided in the digital camera 17. The size of the frame 19 is set according to the specified converted resolution. The frame 19 can be moved up, down, left, and right using the direction buttons 20. The operator moves the frame 19 to a desired location using the direction buttons 20 and then presses the determination button 21 to determine the cutout range. The image data frame cut out from the image data frame before the conversion becomes the image data frame after the resolution conversion.

Finally, in step 16, recompression is performed at the selected compression ratio. If the conversion by the recording mode selected in step 8 does not require the conversion of the image data, the processing of FIG. 4 is not executed.

FIG. 7 is a diagram showing a procedure of one embodiment relating to audio data attached to image data in step 11. First, in step 22, the audio data is expanded. Next, in step 23, recompression is performed at the selected compression ratio. If the conversion in the recording mode selected in step 8 does not require the conversion of the audio data, the processing in FIG. 7 is not executed.

FIG. 8 is a diagram showing a procedure of another embodiment relating to the conversion of image data in step 11 of FIG. First, in step 13a, image data is expanded. If conversion by color reduction is required, color reduction processing of the image data obtained in step 13a is performed in step 14a. As a method of the color reduction processing, for example, a method of lowering the color resolution can be considered. If the color resolution of each pixel of the image data before conversion is 8 bits for each RGB and the color resolution after conversion is 8 bits in total for RGB, for example, R and G are each 3 bits, B
Is reduced to 2 bits by reducing the bit allocation for color quantization. By this color reduction processing, the amount of data relating to color for each pixel of the image is determined in step 15a.
Can be reduced to one third before the recompression process.

FIG. 9 is a diagram showing the procedure of another embodiment relating to the conversion of image data in step 11 of FIG. First, in step 13b, image data is expanded. If compression processing by frame dropping is necessary, frame dropping processing of the image data obtained in step 13b is performed in step 14b. As a method of frame drop processing, for example,
A method of discretely sampling dense moving image data by thinning out frame data from continuous image data frames can be considered. Depending on the degree of compression, a strobe-like image can be selected from a smooth moving image. FIG. 10A shows, as an example, a case where data of an even frame is dropped. From the moving image data before conversion (FIG. 14A), the moving image data subjected to the frame drop processing of FIG. 14B is obtained. By this frame dropping process, the data amount of the moving image can be reduced to half before the recompression process in step 15b. FIG.
FIG. 3 is a diagram showing a procedure of an embodiment according to the present invention.

First, at step 24, the recording mode designation means 4 allows the user to select a recording mode from among a plurality of recording modes as shown in FIG. Can also be specified. Next, at step 25, the remaining memory capacity is confirmed. As a result, in the case of a still image, the recording capacity per image is estimated from the designated number of images and the remaining memory capacity, and the optimum mode is automatically selected from the shooting modes shown in FIG. However, the recording data size of the actually recorded image data varies depending on the imaging target. Therefore,
At the time of compression, the color, the frame drop rate, the compression rate, and the like are adjusted so as to fall below the estimated capacity. When the recording mode in step 24 is selected, it is preferable that options such as color priority, no frame drop, and no audio can be designated. When the data recording is completed in step 27, it is confirmed whether or not the photographing of the designated number (time) has been completed. If not completed, the process returns to step 25 and the same processing is repeated. This makes it possible to dynamically switch the compression mode in accordance with the remaining memory capacity every time shooting proceeds.

[0030]

As is apparent from the above description, according to the present invention, the data amount is reduced by converting the recording mode of image data and audio data recorded in the digital camera by using a plurality of means. It is possible to re-select the optimal recording mode after shooting if you have selected a recording mode with a larger amount of data than necessary before shooting, and the number of images or audio that can be recorded Alternatively, when the remaining recordable time becomes short, it is possible to increase the data without deleting the already taken data.

Since the effect obtained by the data conversion can be known before the conversion, the useless conversion can be avoided. Furthermore, by preparing options such as re-compression of audio data as well as image data conversion as the data amount reduction, it is possible to increase the possibility of selecting the optimum data amount reduction.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a digital camera of the present invention.

FIG. 2 is a diagram illustrating an example of a recording mode of the digital camera.

FIG. 3 is a diagram showing a procedure of an embodiment of the present invention.

FIG. 4 is a diagram showing a procedure of an embodiment relating to conversion of image data.

FIG. 5 is a diagram showing one embodiment relating to conversion of resolution of image data.

FIG. 6 is a diagram showing an embodiment according to partial designation of a cutout range of image data.

FIG. 7 is a diagram showing a procedure of an embodiment relating to conversion of audio data.

FIG. 8 is a diagram showing a procedure of another embodiment relating to conversion of image data.

FIG. 9 is a diagram showing a procedure of another embodiment relating to conversion of image data.

FIG. 10 illustrates a case where data of an even-numbered frame is dropped as an example of a frame dropping process.

FIG. 11 is a diagram showing a procedure of an embodiment relating to processing for dynamically switching a compression mode.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 imaging means 2 recording means 3 conversion means 4 recording mode designation means 5 recording means 6 data designation means

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H04N 5/781 H04N 5/92 Z 5/907 5/781 510Z 5/91 510K 9/80 5/91 J // H04N 101: 00 R 5/92 H 9/80 Z (72) Inventor Kota Fujimura 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. F-term (reference) 5C022 AA13 AC00 AC11 5C052 AA17 CC11 CC20 DD02 GA02 GB01 GB07 GC05 GE06 5C053 FA08 FA27 GA11 GA18 GA20 GB11 GB22 GB40 JA07 KA04 KA24 KA30 LA02 5C055 AA05 AA06 BA03 BA06 CA03 CA13 EA05 FA21 GA00 GA44 HA00 HA31 5D044 AB08 BC06 CC04 EF01 EF06 GK07

Claims (9)

[Claims] A recording unit that records data; a data designating unit that designates predetermined data from data recorded by the recording unit; and a data amount of data designated by the data designating unit is reduced. A digital camera comprising conversion means for performing conversion. 2. The digital camera according to claim 1, wherein said data comprises image data and audio data. 3. The digital camera according to claim 2, wherein said image data comprises a still image and a moving image. 4. The digital camera according to claim 1, wherein said converting means reduces the data size by reducing the color when compressing the image. 5. The digital camera according to claim 1, wherein said converting means reduces a data size by dropping frames when compressing a moving image. 6. The digital camera according to claim 1, wherein said converting means cuts an arbitrary range in the image data frame to lower the resolution. 7. The digital camera according to claim 1, wherein said converting means reduces a data amount by increasing a compression rate of audio data. 8. The digital camera according to claim 1, wherein before conversion of the data by the conversion unit, an amount of image data and audio data that can be recorded after the conversion is calculated and displayed. A digital camera. 9. The digital camera according to claim 1, wherein said conversion means dynamically determines a compression ratio according to a remaining memory free space.