KR100777286B1 - The device for scanning several photos fast and method for controlling the same - Google Patents

Abstract

The present invention relates to a plurality of still image quick retrieval apparatus and method that can solve the problem that the time required for retrieving the still image unnecessarily long because there are a plurality of still images such as digital photos. The present invention provides a method of decoding still images compressed with a discrete cosine transform (DCT), reducing and calculating the number of AC (high frequency components) detected in the decoding process, and based on the reduced number of AC (high frequency components). And displaying the still images decoded by using the Y component among the Y / Cb / Cr components constituting the color components of the still images. It provides a plurality of still image quick search method characterized in that. Therefore, according to the present invention, it is possible to considerably shorten the time for searching a plurality of still images, and the still images displayed can be checked by the user, which is an excellent effect in terms of efficiency of still image search.

Thumbnail image, AC (high frequency component), Y / Cb / Cr

Description

Multiple still image quick search device and method {The device for scanning several photos fast and method for controlling the same}

1 is a flow chart (flow diagram) showing a plurality of still image retrieval methods according to the prior art.

2 is a flow chart (flow diagram) showing a plurality of still image quick retrieval methods according to the present invention.

3 is a diagram illustrating an example of a screen on which a thumbnail image is displayed;

4 illustrates the number of DC (low frequency component) and AC (high frequency component) according to the present invention.

5 illustrates a 4: 2: 2 format of Y / Cb / Cr.

6 illustrates a data format of Y / Cb / Cr.

7 is a block diagram illustrating a plurality of still image quick retrieval apparatuses according to the present invention.

* Description of the symbols for the main parts of the drawings *

701: video device 702: data supply unit of the still image

703: encoding section 704: decoding section

705: Y component control unit 706: user input unit

707: display unit

The present invention relates to a video device, and more particularly, to a plurality of still image quick search apparatus and method.

With the rapid development of digital technology, the spread of digital television, digital cameras, digital camera phones, and the like is gradually spreading. In addition, a technology for viewing digital camera photos using a digital TV with a large screen has been developed by using advantages such as a digital camera.

In addition, the memory capacity of the digital camera is also increasing. In general, 128-256MB is widely used, and even 4GB or more memory cards are available and sold.

For example, when looking at the storage capacity of a JPEG file that can be inserted into a memory card, an image of approximately 1280 * 720 pixels occupies 250KB, an image of 1600 * 1200 pixels occupies 808KB, and 3264 * 2448 pixels. (pixel) video occupies about 2.24MB.

Therefore, when the size of a still image or photo used in a digital camera is generally 1600 * 1200 pixels, about 300 still images or photos may be stored in a 256MB memory.

However, the size of the JPEG file varies depending on the video file size. For example, if 300 still images or pictures are stored, the number of files that can be displayed on one screen is limited to 15. Therefore, about 20 pages are required to search all the stored pictures. Do.

1 is a flow chart (flow chart) showing a plurality of still image retrieval methods according to the prior art. Referring to FIG. 1, a process of displaying thumbnail images of stored pictures is described below.

A still image compressed with DCT is input (S101). Here, the still image may be a photograph taken directly or a captured photograph of a video.

The DCT (Discrete Cosine Transform) refers to a method of transforming n data into a sum of n Cosine functions to reduce the amount of data and transforming the data to be used in MPEG / JPEG.

Although not shown, the still image compressed with the DCT is compressed through a quantization and entropy encoding step based on a pre-stored table.

Accordingly, the static image compressed by the DCT is subjected to entropy decoding and inverse quantization on the basis of the pre-stored table again (S102).

The entropy decoding and inverse quantized data are inverse discrete cosine transform (IDCT) (S103).

The inverse discrete cosine transform refers to an inverse discrete cosine transform (IDCT), and refers to a process of returning a value of a frequency domain to a luminance value when developing (decoding) a compressed image in the JPEG and MPEG standards. More simply, the reverse process of the DCT can be understood.

Still images that have undergone the IDCT process are displayed in the form of thumbnail images on one screen (S104).

However, the method of searching for still images in the above-described conventional video apparatus has the following problems.

Conventionally, when a large amount of information of a still image file is stored in a high-capacity memory card, there is no function to move to a desired page, so that the still image information displayed on all pages is sequentially checked. There was this.

That is, it takes a long time to configure one screen, and as a result, it takes a long time to search all still image files stored in the memory card.

The present invention is to solve the above problems, an object of the present invention is to display a stored image only in the form of a thumbnail image when displaying the stored still image in the form of a plurality, which can reduce the time to search the stored still image as much as possible The present invention provides a still image quick search apparatus and method.

In order to achieve the above object, the present invention provides a method for retrieving still images in an image device, the method comprising: decoding still images compressed with a discrete cosine transform (DCT), and the number of ACs detected in the decoding process; And calculating the decoded still images based on the reduced number of AC (high frequency component), wherein the displaying comprises Y / Cb constituting color components of the still images. Among the / Cr components, the still images are provided using only the Y component, thereby providing a plurality of still images quick retrieval methods.

In the displaying, the plurality of still images may be output on one screen of the image device in the form of a thumbnail image.

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The calculating may be performed by reducing the number of ACs (high frequency components) detected in the decoding process by half.

In order to achieve the above object, the present invention provides a video device capable of retrieving a still image, the present invention compresses the still image to a DCT, encoding (encoding, coding) encoding, and decoding the still image compressed by the DCT (Decoding) a decoding unit which reduces and decodes the number of detected AC (high frequency components) while decoding, wherein the decoding unit is a component of a Y / Cb / Cr component constituting a color component of the still images compressed with the DCT. It provides a plurality of still image quick search apparatus comprising a Y component control unit for decoding the still images using only a Y component.

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The plurality of still image quick search apparatuses may further include a display unit configured to output the decoded still images in the form of thumbnail images on one screen of the video device.

The plurality of still image quick retrieval apparatuses decode or decode the still images compressed with the DCT by reducing the number of detected AC (high frequency components) and color components of the still images compressed with the DCT. More preferably, the user input unit may further include a user input unit configured to input a signal for deciding whether to decode the still images using only the Y component among the Y / Cb / Cr components.

Therefore, according to the present invention, when displaying the stored still image in the form of a thumbnail image, only the data that is identifiable is output, so that the time required for searching the stored still image can be significantly shortened.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

2 is a flowchart (flow diagram) illustrating a plurality of still image quick retrieval methods according to the present invention. Referring to FIG. 2, a method of searching a plurality of still images at a faster speed is as follows.

As shown in FIG. 2, in comparison to the prior art of FIG. 1, steps S203-1, S203-2, and S203-3 are added in an inverse discrete cosine transform (IDCT) step to display a thumbnail image. The steps were also diversified into three types (S204-1, S204-2, S204-3 steps).

A still image compressed with DCT is input (S201), and an entropy decoding and inverse quantization process of the input data is performed (S202).

Then, the data is decompressed in a state in which data of the still image compressed with the DCT can be displayed through inverse discrete cosine transform (S203).

However, unlike step S203, step S203-1, S203-2, and S203-3 may be added.

First, it is determined whether the quick search function is set (S203-1).

If the quick search function is not set, as a result of the determination (S203-1), the same thumbnail image as the stored original is displayed (S204-3). That is, all data of the stored still image can be loaded, decoded and displayed. However, an example of the screen displayed here is illustrated in FIG. 3C.

On the other hand, if the quick search function is set as a result of the determination (S203-1), the number of DC (low frequency components of still images) is used as it is, but the number of AC (high frequency components of still images) is reduced from the original value. In operation S203-2, the decoding process is performed.

However, there will be no particular limitation on how much the number of ACs will be reduced here. For example, the user may specify a reduction range of the AC number or may be set automatically. Considering both the fast search time and the identifiability, the number of ACs may be set to be cut in half.

4 is a diagram illustrating the number of DC (low frequency component) and AC (high frequency component) according to the present invention. Referring to Figure 4, an example of reducing the number of AC as follows.

Reducing the number of ACs means using only the number of ACs reduced from the last number having an AC value. As shown in FIG. 4, the total number of ACs is 63, but still images can be decoded using only five AC numbers. Examples of thumbnail images displayed at this time are FIGS. 3A and 3B.

In the case where step S203-2 is performed, it is determined whether to decode the compressed still image using only the Y component instead of the Cb / Cr component among the color data of the still image (S203-3). However, even using only the Y component, still images may be identified to some extent.

5 illustrates a 4: 2: 2 format of Y / Cb / Cr. Referring to FIG. 5, the 4: 2: 2 format of Y / Cb / Cr is described as follows.

The format of 4: 2: 2 means that the ratio of the sampling frequency used to digitize the luminance Y and the color difference signals R-Y and B-Y is defined as 4: 2: 2. That is, when Y is sampled four times, RY and BY are sampled twice, and of course, in the case of an image device to which Y / Cb / Cr is applied in the present invention, whether in 4: 2: 2 format or 4: It can be applied in either 1: 1 format.

6 is a diagram illustrating a data format of Y / Cb / Cr. Referring to FIG. 6, the data format of Y / Cb / Cr will be described.

When the Y / Cb / Cr format is 4: 2: 2, the data of the Y component, the Cb component, and the Cr component may be arranged adjacent to each other two, one, and one, which is called an interleave method. do. That is, the data is arranged in such a manner that they are not adjacent to each other.

Alternatively, a method in which all of the Y component data are listed, all of the Cb component data is listed again, and finally all of the Cr component data is listed is called a de-interleave method.

However, regardless of whether the interleaved or deinterleaved method is used, as shown by a dotted line in FIG. 6, since it is used to calculate and decode only the data of the Y component, the main feature of the present invention is that the amount of calculation is reduced. .

If the determination result (S203-3) uses only the data of the Y component, the reduced AC number is used (S203-2), and the luminance component (Y) is not used without using the color difference components (Cb and Cr). Only the decoded thumbnail image may be displayed (S204-1). However, an example of the screen displayed here is shown in FIG.

On the other hand, if the determination result (S203-3) does not use only the data of the Y component, the reduced thumbnail using the reduced AC number (S203-2) and using both the chrominance component and the luminance component, An image may be displayed (S204-2). However, an example of the screen displayed here is shown in FIG.

For reference, it can be seen that the sharpness is relatively lower in the order of (c), (b), (a) of FIG. However, even if it is displayed as shown in (a) of FIG. 3, the general user can sufficiently identify whether the image is a still image to be searched.

7 is a block diagram illustrating a plurality of still image quick search apparatuses according to the present invention. Referring to Figure 7, the signal flow between the components of a plurality of still image quick search apparatus according to the present invention will be described.

The video device 701 includes a data supply unit 702, an encoder 703, a decoder 704, a Y component controller 705, a user input unit 706, and a display unit 707 of a still image. The video device 701 is not particularly limited, and preferably includes a device capable of outputting a digital still image captured by a digital camera or the like.

The data supply unit 702 of the still image supplies a still image such as a captured image of a picture or a video taken through a digital camera and transmits the still image to the encoding unit 703.

Here, as shown in FIG. 7, the data supply unit 702 of the still image may supply the data of the still image previously stored in the image device 701, or may be connected to an external device such as a digital camera. It is also possible to supply data of a still image by receiving it from a camera or the like.

The encoding unit 703 receiving the still image data compresses the still image data by DCT, and transmits the still image data to the decoding unit 704 in a coded state. Of course, the encoding unit 703 may quantize the data, entropy-code it, and compress it to DCT based on a predetermined table.

The decoding unit 704 performs the entropy decoding and inverse quantization steps, which are opposite processes to the entropy encoding and quantization, on the basis of a preset table of the still images compressed by the DCT.

However, the decoding unit 704 may decode by reducing the number of detected AC (high frequency components) while decoding the still images compressed by the DCT. Of course, there is no particular limit as to how much the number of AC will be reduced. For example, a reduction range of the AC number may be specified through the user input unit 706 or may be set automatically. Considering both the fast search time and the identifiability, it may be set to reduce the number of ACs in half.

In addition, the decoding unit 704 decodes only the luminance (Y) component among the Y / Cb / Cr components constituting the color components of the still images compressed by the DCT, and the remaining color difference signal (RY, BY) components. They may include the Y component control unit 705 for controlling not to calculate. Of course, the Y component controller 705 is not included in the decoder 704, but may be configured independently.

In this case, the user input unit 706 may control the decoding unit 704 to input a signal for determining whether to reduce the number of ACs while decoding the still images compressed with the DCT, or the DCT A signal for determining whether to use Y component data among the Y / Cb / Cr components constituting the color component of the compressed still images may be input.

The decoding unit 704 and the Y component controller 705 may be controlled by a signal input through the user input unit 706, and the display unit 707 based on the controlled still image data. ) May output the still image in the form of a thumbnail image.

If it is controlled that the number of ACs is not reduced through the user input unit 706, a clear still image identical to the original data is output through the display unit 707, for example, as shown in FIG. Can be.

However, when the number of ACs is reduced through the user input unit 706 and a signal is input to decode without using the Y (luminance) component data, for example, as shown in FIG. Still images that are not displayed may be output through the display unit 707.

When the number of ACs is reduced through the user input unit 706 and Y (luminance) component data is used, and a signal is input to decode without using only Cb / Cr component data, which is a color difference signal, for example, As shown in (a) of FIG. 3, a still image which is not clearer than the original data may be output through the display unit 707.

That is, the sharpness worsens in the order of (c), (b), and (a) of Fig. 3, but the amount of data to be calculated is much reduced, so that the display processing speed becomes faster.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

The effects of the plurality of still image quick retrieval apparatus and method according to the present invention described above are as follows.

The present invention can significantly reduce the speed of displaying a large number of still images by decoding only the remaining data without partially decoding the number of ACs or without using the Y (luminance) component without decoding all the data of the still images. It has an effect. Therefore, there is an effect that a user using the present invention can easily retrieve the desired picture.

Claims (8)

In the method for retrieving still images in the video device, Decoding still images compressed with a discrete cosine transform (DCT); Reducing and calculating the number of ACs (high frequency components) detected in the decoding process; And Displaying the decoded still images based on the reduced number of ACs (high frequency component), The displaying may include displaying the still images using only the Y component among Y / Cb / Cr components constituting the color components of the still images. The method of claim 1, The displaying step, The plurality of still images quick search method characterized in that for outputting a plurality of still images in the form of a thumbnail image (Thumbnail Image) on one screen of the video device. delete The method of claim 1, The calculating step, And calculating by reducing the number of AC (high frequency components) detected in the decoding process in half. In the video device capable of searching still images, An encoding unit which compresses and codes still images by DCT; And A decoding unit configured to reduce and decode the number of detected AC (high frequency components) while decoding (decoding) and decoding the still images compressed by the DCT, The decoding unit includes a Y component controller for decoding the still images using only the Y component among the Y / Cb / Cr components constituting the color components of the still images compressed by the DCT. Still image quick search device. delete The method of claim 5, And a display unit for outputting the decoded still images in the form of thumbnail images on one screen of the video device. The method of claim 7, wherein Y / Cb / Cr configuration to configure whether or not to decode by decoding the number of AC (high frequency component) detected while decoding (decoding) the still images compressed with the DCT. And a user input unit for inputting a signal for deciding whether to decode the still images using only the Y component among the elements.

Images