BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The present invention relates to computer network environments. More specifically, the present invention relates to accessing electronic documents. 
   2. Description of Related Art 
   Information on the World Wide Web is typically made available by structuring the information into a visual presentation. Hypertext Markup Language (HTML) is used by the web author to define the visual structure. The end user is presented with this information by viewing the information on a computer display, after the information has been rendered into a visual format by a web browser (e.g. Netscape Navigator or Microsoft Internet Explorer). 
   However, the images displayed by conventional web browsers may not be clear enough for users with visual impairments. Though web users with visual impairments can set a web browser to default to a larger font for readability, it is often desirable for this impaired user to see a larger, more detailed version of an image. Currently, there is no way for the user to know if there is a higher resolution image available on the same web page. With today&#39;s web pages, the user must access an alternate version of the image via a link to an alternate web page, or an alternate image file. Current web browsers may allow the user to magnify portions of a web page (including images), but this magnification does not adjust picture resolution, resulting in a grainy image. 
   Therefore, it would be desirable to have a method for directly accessing alternate sizes of an image, with corresponding adjustments in resolution to maintain sharp picture quality. 
   SUMMARY OF THE INVENTION 
   The present invention provides a method, program and apparatus for providing access to alternate images in an electronic document. The present invention comprises identifying an initial image to be displayed in an electronic document (typically a web page) and then determining if alternate versions of the image are available for display. If alternate versions of the image are available, they are provided within the same electronic document. The alternate images differ from the initial image in size and resolution, allowing users with visual impairments to access larger, higher resolution images. The user accesses the alternate images by means of a selector displayed within the electronic document. When selected, the alternate image replaces the initial image in the electronic document, and the document is reformatted. 


   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
       FIG. 1  depicts a pictorial representation of a network of data processing systems in which the present invention may be implemented; 
       FIG. 2  depicts a block diagram of a data processing system that may be implemented as a server in accordance with a preferred embodiment of the present invention; 
       FIG. 3  depicts a block diagram illustrating a data processing system in which the present invention may be implemented; 
       FIG. 4  depicts a block diagram of a browser program in accordance with a preferred embodiment of the present invention; 
       FIG. 5  depicts a pictorial diagram illustrating reflowing of the text on a web page in accordance with the present invention; and 
       FIG. 6  depicts a flowchart illustrating the process of presenting alternate image resolutions in accordance with the present invention. 
   


   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   With reference now to the figures,  FIG. 1  depicts a pictorial representation of a network of data processing systems in which the present invention may be implemented. Network data processing system  100  is a network of computers in which the present invention may be implemented. Network data processing system  100  contains a network  102 , which is the medium used to provide communications links among various devices and computers connected together within network data processing system  100 . Network  102  may include connections, such as wire, wireless communication links, or fiber optic cables. 
   In the depicted example, a server  104  is connected to network  102  along with storage unit  106 . In addition, clients  108 ,  110 , and  112  also are connected to network  102 . These clients  108 ,  110 , and  112  may be, for example, personal computers or network computers. In the depicted example, server  104  provides data, such as boot files, operating system images, and applications to clients  108 ,  110 , and  112 . Clients  108 ,  110 , and  112  are clients to server  104 . Network data processing system  100  may include additional servers, clients, and other devices not shown. In the depicted example, network data processing system  100  is the Internet with network  102  representing a worldwide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with each other. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, government, educational and other computer systems that route data and messages. Of course, network data processing system  100  also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN).  FIG. 1  is intended as an example, and not as an architectural limitation for the present invention. 
   Referring to  FIG. 2 , a block diagram of a data processing system that may be implemented as a server, such as server  104  in  FIG. 1 , is depicted in accordance with a preferred embodiment of the present invention. Data processing system  200  may be a symmetric multiprocessor (SMP) system including a plurality of processors  202  and  204  connected to system bus  206 . Alternatively, a single processor system may be employed. Also connected to system bus  206  is memory controller/cache  208 , which provides an interface to local memory  209 . I/O bus bridge  210  is connected to system bus  206  and provides an interface to I/O bus  212 . Memory controller/cache  208  and I/O bus bridge  210  may be integrated as depicted. 
   Peripheral Component Interconnect (PCI) bus bridge  214  connected to I/O bus  212  provides an interface to PCI local bus  216 . A number of modems may be connected to PCI bus  216 . Typical PCI bus implementations will support four PCI expansion slots or add-in connectors. Communications links to network computers  108 ,  110 , and  112  in  FIG. 1  may be provided through modem  218  and/or network adapter  220  connected to PCI local bus  216  through add-in boards. 
   Additional PCI bus bridges  222  and  224  provide interfaces for additional PCI buses  226  and  228 , from which additional modems or network adapters may be supported. In this manner, data processing system  200  allows connections to multiple network computers. A memory-mapped graphics adapter  230  and hard disk  232  may also be connected to I/O bus  212  as depicted, either directly or indirectly. 
   Those of ordinary skill in the art will appreciate that the hardware depicted in  FIG. 2  may vary. For example, other peripheral devices, such as optical disk drives and the like, also may be used in addition to or in place of the hardware depicted. The depicted example is not meant to imply architectural limitations with respect to the present invention. 
   The data processing system depicted in  FIG. 2  may be, for example, an IBM RISC/System 6000 system, a product of International Business Machines Corporation in Armonk, N.Y., running the Advanced Interactive Executive (AIX) operating system. 
   With reference now to  FIG. 3 , a block diagram illustrating a data processing system is depicted in which the present invention may be implemented. Data processing system  300  is an example of a client computer. Data processing system  300  employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Accelerated Graphics Port (AGP) and Industry Standard Architecture (ISA) may be used. Processor  302  and main memory  304  are connected to PCI local bus  306  through PCI bridge  308 . PCI bridge  308  also may include an integrated memory controller and cache memory for processor  302 . Additional connections to PCI local bus  306  may be made through direct component interconnection or through add-in boards. In the depicted example, SCSI host bus adapter  312 , and expansion bus interface  314  are connected to PCI local bus  306  by direct component connection. In contrast, local area network (LAN) adapter  310 , audio adapter  316 , graphics adapter  318 , and audio/video adapter  319  are connected to PCI local bus  306  by add-in boards inserted into expansion slots. Expansion bus interface  314  provides a connection for a keyboard and mouse adapter  320 , modem  322 , and additional memory  324 . Small computer system interface (SCSI) host bus adapter  312  provides a connection for hard disk drive  326 , tape drive  328 , CD-ROM drive  330 , and DVD drive  332 . Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors. 
   An operating system runs on processor  302  and is used to coordinate and provide control of various components within data processing system  300  in  FIG. 3 . The operating system may be a commercially available operating system, such as Windows 2000, which is available from Microsoft Corporation. An object-oriented programming system such as Java may run in conjunction with the operating system and provide calls to the operating system from Java programs or applications executing on data processing system  300 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented programming system, and applications or programs are located on storage devices, such as hard disk drive  326 , and may be loaded into main memory  304  for execution by processor  302 . 
   Those of ordinary skill in the art will appreciate that the hardware in  FIG. 3  may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in  FIG. 3 . Also, the processes of the present invention may be applied to a multiprocessor data processing system. 
   As another example, data processing system  300  may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system  300  comprises some type of network communication interface. As a further example, data processing system  300  may be a Personal Digital Assistant (PDA) device, which is configured with ROM and/or flash ROM in order to provide non-volatile memory for storing operating system files and/or user-generated data. 
   The depicted example in  FIG. 3  and above-described examples are not meant to imply architectural limitations. For example, data processing system  300  also may be a notebook computer or hand held computer in addition to taking the form of a PDA. Data processing system  300  also may be a kiosk or a Web appliance. 
   Turning next to  FIG. 4 , a block diagram of a browser program is depicted in accordance with a preferred embodiment of the present invention. Browser  400  includes a user interface  402 , which is a graphical user interface (GUI) that allows the user to interface or communicate with browser  400 . This interface provides for selection of various functions through menus  404  and allows for navigation through the navigation button  406  or selections. For example, menu  404  may allow a user to perform various functions, such as saving a file, opening a new window, displaying a history, and entering a URL. Navigation  406  allows for a user to navigate various pages and to select web sites or documents for viewing. For example, navigation  406  may allow a user to see a previous page or a subsequent page relative to the present page. User preferences may be set through preferences  408 . 
   Communications  410  is the mechanism with which browser  400  receives documents and other resources from a network such as the Internet. Further, communications  410  is used to send or upload documents and resources onto a network. In the depicted example, communication  410  uses HTTP. However, other protocols are possible. Documents that are received by browser  400  are processed by language interpreter  412 , which includes an HTML unit  414 . Language interpreter  412  will process a document for presentation on graphical display  418 . In particular, HTML statements are processed by HTML unit  414  for presentation. Browser  400  also includes cache memory  416 . 
   Graphical display  418  includes layout unit  420 , rendering unit  422 , and window management unit  424 . These units are involved in presenting web pages to a user based on results from language interpretation  412 . 
   Browser  400  is presented as an example of a browser program in which the present invention may be embodied. Browser  400  is not meant to imply architectural limitations to the present invention. Presently available browsers may include additional functions not shown or may omit functions shown in browser  400 . As used herein, the term “browser” encompasses any software application used to view or navigate for information or data (i.e. something that assists a user to browse) in a local or distributed data base where the distributed database is typically the Internet or World Wide Web. 
   It should also be noted that the present invention may also be applied to word processing and desktop publishing applications, as well as any other applications which involve placing images within electronic documents. 
   The present invention provides a method to make web images more accessible to people who are vision impaired (or want to view a more detailed image) by providing access to multiple-sized versions of an image on a web page. The multiple images are accessed from the web and displayed at the location of the original image when the person desires to see a larger image. This is accomplished without accessing a new web address or changing the rest of the web page&#39;s content. Unlike prior art approaches which simply magnify an image without adjusting picture resolution, the present invention allows the user to view a larger image with the proper adjustment in resolution needed to maintain a sharp picture quality. The new image is displayed, along with reflowing of the web page. 
   The present invention requires an addition to the HTML/XML standards to allows an ALT attribute for the &lt;IMG&gt; tag which can specify multiple images. 
   Referring to  FIG. 5 , a pictorial diagram illustrating reflowing of the object text on a web page is depicted in accordance with the present invention. Flow is the manner in which text on a web page is arranged in order to accommodate an image or other object rendered by the browser. Reflowing involves adjusting the text layout to accommodate changes in the size of the image. In  FIG. 5 , web pages  500  and  510  illustrate the reflowing of text required to accommodate the transition from the smaller image  501  to a larger image  511 . 
   This process can be repeated for several sizes of images, until the user reaches the size of image that he finds most readable. When the user is finished viewing the image, he can then reverse the process and bring back the smaller images, again providing more page/screen space for text and other objects. 
   The present invention provides several advantages:
         The present invention solves the problem of having to go to a new web page, when the user needs to see a larger, more detailed image.   Additional versions of the image may be transmitted while the user is viewing the first image, thereby minimizing perceived transmission time and web URL access time.   Once a different size image is downloaded, it is cached along with the web page, allowing for quick changes among the different sizes of images.       

   In addition, the present invention is useful for easily implementing the common web application of a web page with a thumbnail picture, which then links to a full-size picture page (often referred to as a web photo album). With this thumbnail approach, a separate page is not needed for the alternate image sizes. As stated above, the browser may continue to download the larger sized images into memory while the user is viewing the first image version, which reduces the user&#39;s perceived wait time. In another embodiment, the alternate images may be stored on a server, rather than in cache memory. 
   A user may also customize the browser. For example, the desired resolution of alternate images can be specified according to the client computer&#39;s connection speed. If the connection speed is slow, the user may wish to sacrifice some image resolution for the sake of faster download. In addition, the user may preset the accessibility indicators of the browser, such as the default size of indicator arrows. Without this option, a user with severe visual or motor impairments may not even be able to effectively use the browser to access a larger image. By presetting the browser to automatically display larger indicator controls, this impaired user may more easily navigate a web page and access alternate images. 
   As a further option, the user may preset the browser to automatically display a certain image size as the default image. For example, rather than always starting from a small original image and working up in sizes, the user may wish to set the browser to display an intermediate size image. 
   Referring to  FIG. 6 , a flowchart illustrating the process of presenting alternate image resolutions is depicted in accordance with the present invention. The &lt;IMG&gt; HTML tag uses the source (SRC) attribute to identify the initial original image to display as the web page is first rendered (step  601 ). If the web page contains alternate images for display, the HTML image tag has an alternate image attribute, such as ALTIMAGE, which specifies alternate image files. 
   The browser determines if the image has alternate images for display (step  602 ). If there are no alternate images available, the browser simply displays the original image (step  605 ). If the web page does contain alternate images, the browser queries the ALTIMAGE attribute of the &lt;IMG&gt; tag specifying the alternative image files (step  603 ). This alternate image attribute would be similar to the ALT attribute, which provides alternate text for an image. However, the ALTIMAGE attribute can be used multiple times to allow for several alternate larger, higher resolution images. The web browser overlays a lower corner of the image with small right and left arrows (step  604 ), and then displays the original image (step  605 ). 
   If the user clicks on the right arrow (step  606 ), the alternate larger image is accessed by the web browser and displayed on the page (step  607 ). If the new image has another larger alternate image, the browser also displays a right arrow in its corner. In addition, the browser displays a left arrow in the corner whenever it can bring the user back to a previous alternate image or the original image. In this way, the user can choose to go on to another larger image, if available, or back to a previous image. 
   The design of the present invention can be implemented with the display of the arrows being a web browser view option. If the user chooses not to have the browser display the arrows in the corner of the image, the user could still cycle through the alternate images by clicking on the image itself. 
   The present invention can also be implemented by the use of custom plug-ins or special Java applets. However, both of these methods would require special tools, would be slower in download and web page display, and would require additional work by the web page developer to implement the web page. 
   It is important to note that while the present invention has been described in the context of a fully functioning data processing system, those of ordinary skill in the art will appreciate that the processes of the present invention are capable of being distributed in the form of a computer readable medium of instructions in a variety of forms, and that the present invention applies equally regardless of the particular type of signal bearing media actually used to carry out the distribution. Examples of computer readable media include recordable-type media, such as a floppy disk, a hard disk drive, a RAM, CD-ROMs, DVD-ROMs, and transmission-type media, such as digital and analog communications links, wired or wireless communications links using transmission forms, such as, for example, radio frequency and light wave transmissions. The computer readable media may take the form of coded formats that are decoded for actual use in a particular data processing system. 
   The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
A method, program and apparatus for providing access to alternate images in an electronic document are provided. The present invention comprises identifying an initial image to be displayed in an electronic document (typically a web page) and then determining if alternate versions of the image are available for display. If alternate versions of the image are available, they are provided within the same electronic document. The alternate images differ from the initial image in size and resolution, allowing users with visual impairments to access larger, higher resolution images. The user accesses the alternate images by means of a selector displayed within the electronic document. When selected, the alternate image replaces the initial image in the electronic document, and the document is reformatted.