KR20070018541A - Multiple resolution embedded image file format and its efficient network transfer method - Google Patents

Abstract

The present invention relates to an image file format used in a computer and an efficient network transmission technique thereof. Improved the method of storing a single resolution image in an existing single file and transmitting the entire file to save network traffic by storing the required number of different resolution image data in one file and selectively transmitting it according to user needs. Can be reduced. To this end, the present invention comprises the steps of analyzing the original image file, converting the image data of each resolution according to the user's request, embedding the image data of each resolution in one file, requesting the image file to the network server It is characterized in that it comprises a step for processing, the step of processing the transmission of the image file in the network server.

Image file, file format, web browser, network transfer, resolution

Description

Multiple resolution embedded image file format and its efficient network transfer method

1 is a schematic representation of an image file format according to the prior art

2 is a schematic representation of a multi-resolution embedded image file format in accordance with the present invention.

3 is a flowchart illustrating a network transmission process of a server according to an image file request of a user

<Explanation of symbols for the main parts of the drawings>

101, 201: file header

202, 205: image header

102, 203, 206: image data

204, 207: Image Trailer

208: Repeat any number of image headers, image data, and image trailer bundles

103, 209: File Trailer

The present invention relates to an image file format capable of storing image data of various resolutions in a single file and an efficient network transmission of this file format.

Currently, in the image file format commonly used on the Internet, only one resolution image data is stored in one file. This is not a problem for simply storing images, but when attempting to use them on the Internet, it is a main cause of deterioration of image quality and unnecessary network traffic.

When considering web surfing, the size of an image file that is displayed to a user in a web page containing text is often 400 pixels or less in width. Considering that the resolution of a digital camera that is commonly used in recent years is 300 mega pixels or more, the size of the image file actually displayed, that is, the resolution is very small. Therefore, the image cannot contain much information.

Therefore, users want to see a larger image at a higher resolution when they click on the image even if they see a small image within a web page that contains text. In this case, in the past, a method of displaying an actual large resolution image by simply reducing the visible size or using two files of different resolutions has been used.

First of all, if the image of the actual large resolution is forced to be resized in the HTML IMG tag, the web browser does not perform a high quality resize operation to reduce the overhead. For example, if you look at the photo album function of the 'mini homepage' service of the parent company, which is the most used in Korea, the resolution displayed on the screen is fixed at 400 pixels horizontally, so when you upload more than this, the image looks quite distorted. Also, in practice, a large file size is transmitted to the network, which increases traffic. Therefore, many people upload an image after reducing the size of the image to 400 pixels through a separate program that performs a high quality resize operation.

Next, using two files of different resolution, the first web page displays a small resolution of the file at its actual size and the original large image displays a new window when you click on it to manage two different files. There is a problem. This doubles the number of files and takes up a lot of space. In addition, it is virtually impossible to create and upload files of different resolutions when a typical user composes a web page.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for storing image data of various resolutions in one image file and efficiently transmitting it in a network such as the Internet.

The present invention for achieving the above object comprises the steps of analyzing the original image file, converting the image data of each resolution at the request of the user, embedding the image data of each resolution in a single file, the image file And a step for making a request to the network server, the network server processing the transmission of the corresponding image file.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic representation of an existing image file format.

Although there are some detailed differences depending on actual image file formats such as JPG, TIFF, GIF, BMP, and PNG, which are currently commonly used, the file header 101 mainly includes image file format format, resolution, and image data 102. Preliminary information is included, and extended information such as creation time and digital camera information can be added as needed. Image data 102 stores information about an actual image mainly in a compressed form. Finally, the checksum byte for checking whether a file is damaged is mainly located in the file trailer 103.

As can be seen from the above description, the existing image file has a disadvantage of including only one image. Of course, the gif89a format, commonly referred to as animated gif, can contain multiple images for animation effects, but this is a format developed for animation effects only to images of the same resolution, and above all, a single image cannot be imported. . Therefore, in the case of the existing image file, as described above, when constructing a web page, the problem of image distortion, traffic increase, or dual file management cannot be avoided.

2 is a schematic representation of a multi-resolution embedded image file format according to the present invention.

The file header 201 and the file trailer 209 are the same as the existing basic format, so that the first image can be loaded even in an image display module which does not support this format, thereby enabling backward compatibility. Multiple images consist of the header 202, data 203, trailer 204, header 205, data 206, trailer 207 for the second image, and the same format. The image may be located before the file trailer 208. The trailer for each image is to support information such as checksum byte for a single image. In addition, by placing pointer information of multiple image data blocks (header, data, trailer) in the extended information area of the file header, each block can be accessed. This pointer information can be kept backward compatible by being located in the extension information area of the file header.

3 is a flowchart illustrating an efficient network transmission scheme through selective transmission of a multi-resolution embedded image file format according to the present invention.

First, a user requests an image file from a server having an image file (301). The server receives the request and checks whether it is an extension request (302). If it is not an extension request, the entire file is transmitted in the conventional manner (308). In the case of the extension request, the image file is opened (303), the header is analyzed (304) and the file header is transmitted first (305). For reference, the order of 304 and 305 may be reversed. Then, the header analysis determines which image is requested and transmits an image (header, data, trailer) of the selected resolution (306). Finally, the file trailer is transferred to finish the image file transfer (307). As an example of error processing, when there is no image of the resolution requested in the header analysis step, the image of the native resolution may be transmitted in step 306.

If you apply it to a web server over HTTP (HyperText Transfer Protocol), you can extend the existing IMG tag of HTML and use it while maintaining backward compatibility with little modification of existing HTML code. By default, IMG tags requesting images from HTML follow the format <IMG SRC = "http://www.kipo.go.kr/img1.jpg">. The web server address "www.kipo.go.kr" and the image file name "img1.jpg" are for illustration purposes only. Expand it as follows: <IMG SRC = "http://www.kipo.go.kr/img1.jpg?1"> In other words, add a "? 1" after the existing address to specify the resolution to request. Here, 1 means the number of image sequences in the multiple image file. Of course, this part may have a specific form such as "? Res_h = 1024 & res_v = 768", but simply specifying the sequence number of the image in the multiple image file may reduce the burden of header analysis 304 of the web server. It is more recommended. Of course, this part is an implementation issue and can be changed as needed. The reason why the selective request of multi-resolution image files through IMG markup extension is excellent is that there is little modification, and most existing web servers accept this part as an environment variable. It can be maintained.

Also, in web pages such as photo albums that upload images, when a user selects a file with a higher original resolution and uploads it, the file is converted to create a lower resolution image that fits the webpage's composition and combined with the original resolution image. It has the advantage of minimizing user intervention by creating a Microsoft ActiveX Control that automatically generates multi-resolution image files. On the server, you can create an IMG tag that shows a small resolution image optimized for page composition on the main page, and an IMG tag that shows the original resolution image when the image is clicked. This allows smaller resolution images to be the same size on the page composition, so that requests for larger resolutions can be made for efficient network transfers while maintaining image quality only if you want to look clean and see more detail. If the entire file is needed, the entire file can be requested by not using the extended IMG tag. Also, each image does not necessarily have to be the same image. For example, in the case of a shopping mall site, pictures taken in various configurations and directions may be embedded in a single file.

As described above, by eliminating the image distortion problem caused by the resolution mismatch according to the present invention, the improvement of the image quality seen by the actual user, the convenience of single file management of the multi-resolution image, the network traffic according to the selective transmission according to the user's needs A reduction effect can be obtained.

In addition, in implementing the invention as a web environment, the initial implementation required by the service provider is very small, and from the user's perspective, through the Active-X Control or other client assistive programs, the general user can directly deal with the multi-resolution problem without any intervention. There are advantages to it. It also has the advantage of maintaining backward compatibility in using HTML code to request an image file from a web server.

In addition, since the image file format itself can maintain backward compatibility, both the server and the client can partially and sequentially upgrade, which has the advantage of minimizing the actual implementation problem.

Finally, the above-mentioned web environment is an example, and it can be said that the concept can be used for various environments such as an image file viewer and a file transfer protocol (FTP).

Claims (4)

In the method of creating a multi-resolution image file, Analyzing the original image file, converting image data of each resolution according to a user's request, and embedding the image data of each resolution into one file. The method of claim 1, A method of writing an image block (header, data, trailer) pointer in file header extension information for converting image data of each resolution according to a user's request. A file format consisting of a file header, a plurality of image blocks (image header, image data, image trailer), and file trailer in the step of embedding image data of each resolution into a single file. In the method for transmitting a multi-resolution image file over a network, Requesting the image file to the network server, confirming that the server is an extension request, opening an image file, analyzing a header, transmitting a file header, transmitting an image of a selected resolution, transmitting a file trailer. In applying the invention to the web environment, How to create multiple image files with minimal user intervention using ActiveX Control. How to extend HTML IMG markup for multiple image file requests and processing on the server.

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