JP2018037828A - Terminal device, image generation program, storage medium, and image generation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device that determines a compression method on the basis of a thumbnail image and efficiently transmits compressed image data.SOLUTION: An information processing device 5 includes: a thumbnail image generation unit 42 for generating a thumbnail image of an image indicated by image data on the basis of the image data; an identification information addition unit 44 for determining a compression method for compressing the image data on the basis of the thumbnail image generated by the thumbnail image generation unit 42, and adding identification information including the determined compression method beforehand; an image compression unit 50 for compressing the image data on the basis of the compression method indicated by the identification information added by the identification information addition unit 44; and a communication unit 38 for transmitting the image data compressed by the image compression unit 50 via communication.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a terminal device, an image generation program, a storage medium, and an image generation method.

When the output image data of a personal computer is enlarged and projected by a projector device or the like, it is necessary to connect the two with a cable and transmit the image data held by the personal computer. In recent years, wireless communication systems that transmit image data using an infrared modulation method or a file transfer technique using a wireless LAN instead of using a cable have been commercialized.
As is well known, when a large amount of data such as image data is transmitted wirelessly, the image data is compressed to reduce the data amount, and then the compressed image data is transmitted, so that the image data can be efficiently transmitted. Realizes transmission.
In Patent Document 1 below, when image data is compressed, the characteristics of the image indicated by the image data are acquired, and either the JPEG method or the PNG method is selected as the compression method based on the acquired characteristics.

JP 2004-193818 A

However, since the determination process for acquiring the image characteristics and determining the compression method is performed immediately before the compression process of the image data, it takes a long time to compress and transmit the image data to be transmitted. It could not be transmitted efficiently.
The present invention has been made in view of the above-described problems, and an object thereof is to efficiently transmit compressed image data.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The terminal device according to this application example includes a thumbnail image generation unit that generates a thumbnail image of an image indicated by image data based on the image data, and the image data based on the thumbnail image generated by the thumbnail image generation unit. A compression method for compressing the image, and an identification information adding unit that preliminarily assigns identification information including the determined compression method, and the compression method indicated by the identification information provided by the identification information adding unit. An image compression unit that compresses data, and a transmission unit that transmits the image data compressed by the image compression unit via communication.

  According to such a configuration, a compression method for compressing the image data is determined based on the thumbnail image of the image data, and identification information including the determined compression method is given in advance, so that compression is performed when the image data is compressed. Since there is no need to determine the method, it is possible to efficiently execute processing for compressing image data and transmitting it by communication.

[Application Example 2]
In the terminal device according to the application example, it is preferable that the identification information adding unit determines the compression method based on a color change in a plurality of continuous pixels constituting the thumbnail image.

  According to such a configuration, since the compression method is determined based on the color change in a plurality of continuous pixels constituting the thumbnail image, the compression method can be determined according to the color change in the continuous pixels.

[Application Example 3]
In the terminal device according to the application example described above, it is preferable that the identification information adding unit determines the compression method by digitizing the color change frequency and comparing it with a predetermined reference value.

  According to such a configuration, the frequency of color change can be digitized and a compression method can be determined according to comparison with a predetermined reference value.

[Application Example 4]
In the terminal device according to the application example, when the frequency of the digitized color change is equal to or higher than the predetermined reference value, the identification information adding unit determines a first compression method and the digitized color When the frequency of change is less than the predetermined reference value, it is preferable to determine the second compression method.

  According to such a configuration, the first compression method or the second compression method can be determined in accordance with the magnitude relationship between the digitized color change frequency and the predetermined reference value.

[Application Example 5]
In the terminal device according to the application example described above, it is preferable that the first compression method is a JPEG method and the second compression method is a PNG method.

  According to such a configuration, when the frequency of color change is high, compression is performed by the JPEG method, and when the frequency of color change is low, compression is performed by the PNG method, so that the compression efficiency can be improved.

[Application Example 6]
The terminal device according to the application example preferably includes a storage unit that stores the thumbnail image, the identification information, and the image data in association with each other.

  According to such a configuration, thumbnail images, identification information, and image data can be stored in association with each other before compression.

[Application Example 7]
The terminal device according to the application example includes: a display unit that displays the thumbnail image; and a display image determination unit that determines the thumbnail image to be displayed on the display unit, wherein the display image determination unit includes the display unit When the number of the thumbnail images to be displayed exceeds the number that can be displayed on the display unit, the thumbnail image associated with the next image data is not displayed on the display unit, and the thumbnail image, The identification information and the image data are preferably stored in the storage unit.

  According to such a configuration, when the number of thumbnail images to be displayed on the display unit exceeds the number that can be displayed on the display unit, the thumbnail image, the identification information, and the thumbnail image are not displayed on the display unit. Since the image data is stored in the storage unit, the thumbnail image, the identification information, and the image data can be stored in the background of the display process.

[Application Example 8]
In the terminal device according to the application example, when the thumbnail image can be displayed on the display unit, the display image determination unit displays the thumbnail image associated with the next image data stored in the storage unit. It is preferable to read out and display on the display unit.

  According to such a configuration, when the thumbnail image can be displayed on the display unit, the thumbnail image associated with the next image data stored in the storage unit is read and displayed, so that it can be displayed quickly. .

[Application Example 9]
In the terminal device according to the application example, when the thumbnail image displayed on the display unit is selected, the image compression unit stores the image data and the identification information associated with the thumbnail image from the storage unit. It is preferable to read and compress the image data by the compression method indicated by the identification information.

  According to such a configuration, the image data and the identification information associated with the selected thumbnail image are read from the storage unit, and the image data is compressed by the compression method indicated by the identification information, so that the image data can be quickly compressed.

[Application Example 10]
The image generation program according to this application example includes a thumbnail image generation function that generates a thumbnail image of an image indicated by image data based on the image data, and the image based on the thumbnail image generated by the thumbnail image generation function. Determine a compression method for compressing data, based on the identification information providing function that pre-assigns identification information including the determined compression method, and the compression method indicated by the identification information provided by the identification information providing function, An image compression function for compressing image data and a transmission function for transmitting the image data compressed by the image compression function via communication are executed by a computer.

  According to such a configuration, a compression method for compressing the image data is determined based on the thumbnail image of the image data, and identification information including the determined compression method is given in advance, so that compression is performed when the image data is compressed. Since there is no need to determine the method, it is possible to efficiently execute processing for compressing image data and transmitting it by communication.

[Application Example 11]
The storage medium according to this application example stores an image generation program.

[Application Example 12]
The image generation method according to this application example includes a thumbnail image generation step of generating a thumbnail image of an image indicated by image data based on the image data, and the image based on the thumbnail image generated in the thumbnail image generation step. Determine a compression method for compressing data, and based on the compression method indicated by the identification information assigned step that gives the identification information including the determined compression method in advance, and the identification information given in the identification information provision step, An image compression process for compressing image data, and a transmission process for transmitting the image data compressed in the image compression process via communication.

  According to such a method, the compression method for compressing the image data is determined based on the thumbnail image of the image data, and the identification information including the determined compression method is given in advance, so that the compression is performed when the image data is compressed. Since there is no need to determine the method, it is possible to efficiently execute processing for compressing image data and transmitting it by communication.

The figure which shows the hardware constitutions of the information processing apparatus which concerns on embodiment. The block diagram which shows the function structure of information processing apparatus. The flowchart which shows the flow of the process which produces | generates a thumbnail image from an image file. 6 is a flowchart showing details of processing for determining a compression method of image data. The flowchart which shows the flow of a process when the thumbnail image displayed on the display part is selected by the user. The figure explaining the process which determines the compression method of image data.

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

(Embodiment)
FIG. 1 is a diagram illustrating a hardware configuration of an information processing apparatus 5 that is one of terminal apparatuses. In the present embodiment, the information processing apparatus 5 is assumed to be a smart phone that is a high-function mobile phone or a tablet that is a multi-function mobile terminal, but is not limited thereto. For example, a computer device such as a notebook computer or a desktop computer, or a portable image viewer device can be assumed.
The information processing device 5 includes, as hardware, a CPU (Central Processing Unit) 10, a RAM (Random Access Memory) 12, a ROM (Read Only Memory) 14, a flash memory 16, a communication device 18, a display device 20, a pointing device 22, and A memory card reader 24 is provided, which are connected via a bus 26.

The CPU 10 reads basic software, device drivers for each device, various programs such as application software, and various data from the ROM 14 and the flash memory 16, and expands and executes them in a main memory area provided in the RAM 12. It is.
In addition, it is not limited to CPU10, MPU (Micro Processing Unit), DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit) etc. can be assumed.
The communication device 18 includes at least a transmission function (transmission unit), is connected to a network via a public communication network such as a mobile phone, and communicates with an electronic device wirelessly via the network. Also, short-range wireless communication standards such as Bluetooth (registered trademark) (BTLE: including Bluetooth Low Energy), Wi-Fi (registered trademark), Zigbee (registered trademark), NFC (Near field communication), ANT + (registered trademark), etc. Based on the above, it is possible to assume a mode in which a router device and an electronic device are connected to communicate. In the present embodiment, an image display device such as the projector device 60 (FIG. 2) is assumed as an electronic device that is communicably connected to the information processing device 5.

In addition, the communication device 18 can capture image data into the information processing device 5 through communication with an external server device or computer.
The display device 20 assumes a liquid crystal panel or the like, and displays an operation screen for operating the information processing device 5 and a user interface screen for instructing an image to be displayed on the electronic device.
The pointing device 22 is a device for a user to instruct an operation screen and a user interface screen displayed on the display device 20. In the present embodiment, the pointing device 22 is assumed to be a touch pad that forms a touch panel in combination with a liquid crystal panel.
The memory card reader 24 is a device that reads an image file, an image generation program, and the like stored in a storage medium such as an SD memory card (registered trademark).

FIG. 2 is a block diagram illustrating a functional configuration of the information processing apparatus 5. The information processing apparatus 5 includes an image file receiving unit 30, an operation unit 32, a storage unit 34, a display unit 36, a communication unit 38, and a control unit 40.
The image file receiving unit 30 receives a data file including image data. In the present embodiment, the image file receiving unit 30 receives a data file when the memory card reader 24 reads a storage medium or receives it via the communication device 18.

The control unit 40 opens the data file received by the image file receiving unit 30 and sequentially reads the image data.
In the present embodiment, the operation unit 32 corresponds to the pointing device 22, and the storage unit 34 corresponds to the flash memory 16. Further, the display unit 36 corresponds to the display device 20, and the communication unit 38 corresponds to the communication device 18.
The control unit 40 includes a thumbnail image generation unit 42, an identification information adding unit 44, a display image determination unit 46, a compressed image determination unit 48, and an image compression unit 50.
Each function unit of the control unit 40 realizes each function by organically cooperating hardware resources including the CPU 10 and the RAM 12 and various software stored in the ROM 14 and the flash memory 16 and the like. .

The thumbnail image generation unit 42 sequentially acquires image data read from the data file received by the image file reception unit 30, and generates a thumbnail image obtained by reducing the image indicated by the acquired image data. The thumbnail image generating unit 42 sends image data including the generated thumbnail image to the identification information adding unit 44, and sends image data returned from the identification information adding unit 44 to the display image determining unit 46.
The identification information adding unit 44 generates identification information based on the image data of the thumbnail image sent from the thumbnail image generation unit 42. The identification information is information indicating the characteristics of the content indicated by the image data. In the present embodiment, the identification information includes a compression method used when compressing image data.

In this embodiment, when the image indicated by the image data is a photograph, the identification information adding unit 44 determines the first compression method, that is, the JPEG (Joint Photographic Experts Group) method (referred to as JPG compression).
On the other hand, when the image indicated by the image data indicates text information, the second compression method, that is, the PNG (Portable Network Graphics) method (referred to as PNG compression) is determined.
As is well known, when the color of a pixel constituting an image is different from that of an adjacent pixel, JPG compression is more efficient than PNG compression, and when the color of the pixel is the same as the adjacent pixel, JPG PNG compression is more efficient than compression.

In the present embodiment, the compression method is either JPG compression or PNG compression, but is not limited to this. For example, a GIF (Graphics Interchange Format) method or a run length method may be added to the compression method options.
The identification information adding unit 44 writes the generated identification information in a predetermined area of the data structure defined by the image data, and returns the image data in which the identification information is written to the thumbnail image generation unit 42.
The display image determination unit 46 extracts thumbnail image data from the image data sent from the thumbnail image generation unit 42 and sequentially displays the thumbnail images indicated by the extracted thumbnail image data on the display unit 36 as projection candidates of the projector device 60. Let Further, the display image determination unit 46 sequentially stores the image data sent from the thumbnail image generation unit 42 in the storage unit 34. The image data stored in the storage unit 34 includes thumbnail image data and identification information.

In addition, when the number of image data sent exceeds the number of images that can be displayed on the display unit 36 at once, the display image determination unit 46 displays only the number of images that can be displayed. On the other hand, the display image determination unit 46 sequentially stores the image data sent from the thumbnail image generation unit 42 in the storage unit 34 regardless of whether or not the display unit 36 can display.
When the user operates the operation unit 32 and instructs to change the image to be displayed, the display image determination unit 46 reads out the image data stored in the storage unit 34 and extracts thumbnail image data, The extracted thumbnail image is displayed on the display unit 36 instead of the displayed thumbnail image.

In addition, when the user operates the operation unit 32 to instruct an image to be projected to the projector device 60 from the displayed thumbnail images, the display image determination unit 46 determines the image information specified by the user as a compressed image. Send to part 48.
The compressed image determination unit 48 reads image data from the storage unit 34 based on the image information sent from the display image determination unit 46. Here, the compressed image determination unit 48 extracts the identification information from the predetermined area of the read image data, and acquires the compression method included in the identification information. Therefore, since the compression method is extracted from a predetermined area of the image data stored in the storage unit 34, it can be acquired more quickly than in the case where it is determined at the time of image compression.

The compressed image determination unit 48 sends the image data and the compression method read from the storage unit 34 to the image compression unit 50.
The image compression unit 50 compresses the image data according to the compression method sent from the compressed image determination unit 48. The compressed image data is transmitted from the communication unit 38 to the projector device 60.
The projector device 60 receives the image data sent from the information processing device 5, generates an image signal from the received image data, and generates a projection image based on the generated image signal. Furthermore, the projector device 60 optically enlarges the projected image and projects it onto a screen or the like.

Next, according to the flowcharts of FIGS. 3 to 5, processing for generating a thumbnail image from the image file received by the information processing device 5 and transmitting the instructed image data to the projector device 60 (image generation method, image generation program) The flow of will be described. In order to facilitate understanding of the processing, the description will be given with reference to FIG.
FIG. 3 is a flowchart showing a flow of processing for generating a thumbnail image from an accepted image file.
First, the control unit 40 opens the received image file (step S100).
Next, the control unit 40 acquires one piece of image data from the image file (step S102).

Next, the control unit 40 generates a thumbnail image of the acquired image data (step S104) <thumbnail image generation step, thumbnail image generation function>.
Next, the control unit 40 determines a compression method (compression method) for the acquired image data (step S106).
FIG. 4 is a flowchart showing details of the process for determining the compression method of image data (step S106). The process for determining the compression method will be described with reference to FIG.
First, the control unit 40 extracts a predetermined number of pixels from a predetermined location in the thumbnail image (step S120). In this embodiment, as shown in FIG. 6, an extraction filter 200 provided with predetermined extraction windows 202A to 202D is set in advance. The control unit 40 applies the extraction filter 200 to the thumbnail image, and obtains data of a plurality of pixels from locations that match the positions of the extraction windows 202A to 202D. And the control part 40 arranges the data of the acquired several pixel in series in the order of extraction window 202A-202D, and hold | maintains it as pixel data.

Note that the extraction windows 202A to 202D are not limited to the horizontal direction of the thumbnail image, and may be set including the vertical direction and the oblique direction. Further, the extraction windows 202A to 202D are not limited to a linear shape, and may be a curved shape. Further, the positions and number of the extraction windows 202A to 202D may be reset at a predetermined frequency.
Next, the control unit 40 performs an exclusive OR with the pixel data of pixels adjacent in one direction with respect to the pixel data (step S122). In the present embodiment, the frequency at which color changes occur in adjacent pixel data is quantified.
In general, when the image indicated by the image data is the photographic data 205, each pixel corresponds to a part of the image of the subject, so the colors of adjacent pixels are often slightly different. On the other hand, when the image indicated by the image data is text data 210, the character information is drawn with continuous line segments, so the colors of adjacent pixels are the same according to the thickness and length of the line segments, and suddenly Often changes.

Therefore, as shown in FIG. 6, the exclusive OR value XOR1 of the photo data 205 is data in which the true value “1” is continuous. Further, the exclusive OR value XOR2 of the text data 210 is data in which the false value “0” continues and the true value “1” is distributed.
Next, the control unit 40 accumulates each value of the calculation result (step S124). For example, in FIG. 6, in the case of the exclusive OR value XOR1, the integrated value n is “400”. On the other hand, in the case of the exclusive OR value XOR2, the integrated value n is “10”.
Next, the control unit 40 compares the integrated value n with a reference value, and determines whether or not the integrated value n is greater than or equal to the reference value (step S126).

If the integrated value is greater than or equal to the reference value (Yes in step S126), the control unit 40 determines the compression method as JPG compression (step S128), and ends the process for determining the compression method.
On the other hand, when the integrated value is less than the reference value (No in step S126), the control unit 40 determines the compression method to be PNG compression (step S130), and ends the process of determining the compression method.
The reference value (predetermined reference value) is determined in advance, for example, “200”.
Returning to FIG. 3, the control unit 40 writes the determined compression method in the identification information, and adds the identification information to the image data (step S108) <identification information adding step, identification information adding function>.

Next, the control unit 40 stores image data including a thumbnail image and identification information in the storage unit 34 (step S109).
Next, the control unit 40 determines whether or not the thumbnail image of the image data can be displayed on the display unit 36 (step S110).
If the thumbnail image can be displayed on the display unit 36 (Yes in step S110), the control unit 40 displays the thumbnail image on the display unit 36 (step S112), and the process proceeds to step S116.
On the other hand, if the number of images that can be displayed at one time on the display unit 36 is exceeded and thumbnail images cannot be displayed on the display unit 36 (No in step S110), the process proceeds to step S116.

In step S116, the control unit 40 determines whether or not all the image data has been acquired from the image file. When all the image data has been acquired (Yes in step S116), the series of processing ends.
On the other hand, if not all image data has been acquired (No in step S116), the process returns to step S102, and the same processing is performed on the next image data that has not been acquired.
Even if the next thumbnail image cannot be displayed on the display unit 36 by the above processing, the next thumbnail image is generated, the compression method is determined, and the next thumbnail image and the compression method are stored in advance. Can be executed in the background regardless of the display state.

Next, FIG. 5 is a flowchart showing a processing flow when a user selects a thumbnail image from thumbnail images displayed on the display unit 36.
First, the control unit 40 acquires identification information added to the image data of the selected thumbnail image (step S140).
Next, the control unit 40 determines the compression method indicated by the identification information (step S142).
If the compression method indicated by the identification information is JPG compression (Yes in step S142), the control unit 40 compresses the image data by JPG compression (step S144), and proceeds to step S148 <Image compression process, image compression Function>.

On the other hand, when the compression method indicated by the identification information is PNG compression (No in step S142), the control unit 40 compresses the image data by PNG compression (step S146), and proceeds to step S148 <Image compression process, image compression Function>.
In step S148, the control unit 40 transmits the compressed image data to the projector device 60, and ends a series of processes <transmission process, transmission function>.

According to the embodiment described above, since the compression method is determined in advance before the step of compressing the image data, when the desired image data is selected and sent to the projector device 60, the compression method is determined. Since processing is not necessary, the image data selected by a predetermined compression method can be compressed, and the compressed image data can be sent to the projector device 60. Accordingly, it is possible to reduce the time required for enlarging and projecting the thumbnail image selected by the information processing device 5 onto the projector device 60.
As mentioned above, although this invention was demonstrated based on embodiment shown in figure, this invention is not limited to this embodiment, The modification as described below can also be assumed.
(1) Although the compression method is determined based on the color change of the pixel, the compression method may be determined based on the change in the brightness of the pixel in addition to the color change.
(2) The image display device is not limited to the projector device 60, and displays an image / image on a liquid crystal monitor or a liquid crystal television or a PDP (plasma display panel) that displays an image / image on a liquid crystal display panel. Self-luminous display such as a monitor device or a television receiver that displays an image / image on an organic EL display panel called a monitor device or a television receiver, OLED (Organic light-emitting diode), OEL (Organic Electro-Luminescence), etc. Various display devices such as devices are also included.

  5 ... Information processing device, 10 ... CPU, 12 ... RAM, 14 ... ROM, 16 ... Flash memory, 18 ... Communication device, 20 ... Display device, 22 ... Pointing device, 24 ... Memory card reader, 26 ... Bus, 30 ... Image file receiving unit, 32 ... operation unit, 34 ... storage unit, 36 ... display unit, 38 ... communication unit, 40 ... control unit, 42 ... thumbnail image generation unit, 44 ... identification information addition unit, 46 ... display image determination unit 48 ... Compressed image determination unit, 50 ... Image compression unit, 60 ... Projector device, 200 ... Extraction filter, 202A to 202D ... Extraction window, 205 ... Photo data, 210 ... Text data.

Claims (12)

A thumbnail image generating unit that generates a thumbnail image of an image indicated by the image data based on the image data;
An identification information adding unit that determines a compression method for compressing the image data based on the thumbnail image generated by the thumbnail image generation unit, and that assigns in advance identification information including the determined compression method;
An image compression unit that compresses the image data based on the compression method indicated by the identification information provided by the identification information addition unit;
And a transmission unit that transmits the image data compressed by the image compression unit via communication. The terminal device according to claim 1,
The terminal device characterized in that the identification information adding unit determines the compression method based on a color change in a plurality of continuous pixels constituting the thumbnail image. The terminal device according to claim 2,
The terminal device characterized in that the identification information adding unit determines the compression method by digitizing the color change frequency and comparing it with a predetermined reference value. The terminal device according to claim 3,
The identification information adding unit determines a first compression method when the digitized frequency change frequency is equal to or greater than the predetermined reference value, and the digitized color change frequency is the predetermined reference value. If it is less, the terminal device is determined to be the second compression method. The terminal device according to claim 4,
The terminal apparatus according to claim 1, wherein the first compression method is a JPEG method, and the second compression method is a PNG method. The terminal device according to any one of claims 1 to 5,
A terminal device comprising: a storage unit that stores the thumbnail image, the identification information, and the image data in association with each other. The terminal device according to claim 6,
A display unit for displaying the thumbnail image;
A display image determination unit that determines the thumbnail image to be displayed on the display unit,
When the number of the thumbnail images to be displayed on the display unit exceeds the number that can be displayed on the display unit, the display image determining unit displays the thumbnail image associated with the next image data on the display unit. A terminal device, wherein the thumbnail image, the identification information, and the image data are stored in the storage unit without being displayed. The terminal device according to claim 7,
When the thumbnail image can be displayed on the display unit, the display image determination unit reads the thumbnail image associated with the next image data stored in the storage unit and displays the thumbnail image on the display unit. A terminal device characterized by the above. The terminal device according to any one of claims 7 to 8,
When the thumbnail image displayed on the display unit is selected,
The terminal device, wherein the image compression unit reads the image data and the identification information associated with the thumbnail image from the storage unit, and compresses the image data by the compression method indicated by the identification information. A thumbnail image generation function for generating a thumbnail image of an image indicated by the image data based on the image data;
An identification information providing function for determining a compression method for compressing the image data based on the thumbnail image generated by the thumbnail image generation function, and for providing identification information including the determined compression method in advance;
An image compression function for compressing the image data based on the compression method indicated by the identification information given by the identification information giving function;
An image generation program causing a computer to execute a transmission function of transmitting the image data compressed by the image compression function via communication.   A storage medium storing the image generation program according to claim 10. A thumbnail image generation step of generating a thumbnail image of an image indicated by the image data based on the image data;
An identification information providing step of determining a compression method for compressing the image data based on the thumbnail image generated in the thumbnail image generating step and pre-applying identification information including the determined compression method;
An image compression step for compressing the image data based on the compression method indicated by the identification information given in the identification information giving step;
And a transmitting step of transmitting the image data compressed in the image compressing step via communication.

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