Abstract:
A program is disclosed for permitting a user to directly annotate and capture data associated with a Java™ based applet application running within a conventional browser program. The program addresses sand-box local security restrictions otherwise attendant with such applet by exploiting non-local system resources that are accessible to such types of applications.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The present application is a divisional application of Ser. No. 09/172,191 filed Oct. 13, 1998 entitled System And Method For Permitting a Software Routine Having Restricted Local Access to Utilize Remote Resources to Generate Locally Usable Data Structure, Which is hereby incorporated by reference. 

   CROSS REFERENCE TO MICROFICHE APPENDIX 
   Appendix A, which forms part of this disclosure and is incorporated by reference herein, is a microfiche appendix consisting of 1 sheet of microfiche having a total of 58 frames. Microfiche Appendix A is a list of computer programs and related data in an embodiment of the present invention, which is described more completely below. 
   FIELD OF THE INVENTION 
   The invention relates generally to a computer software routine which facilitates and expands the functionality of secure program routines running on a local client computing system by permitting such routines to interact with resources located at a remote server. The invention has particular use in increasing the utility of routines embodied in Java® applets, which, while running locally on a user&#39;s system, can nonetheless be configured to access resources from a remote server so as to circumvent security mechanisms otherwise prohibiting such applets from generating or reading local data structures. 
   COPYRIGHT NOTICE 
   A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the xerographic reproduction by anyone of the patent document or the patent disclosure in exactly the form it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
   BACKGROUND OF THE INVENTION 
   The use of the world wide web (WWW) is increasing rapidly, and so of course is the demand for intelligent systems and software which can permit users to better and more easily explore its offerings. To access information on the WWW, a user typically utilizes a browser program having a graphical interface (such as those offered by such companies as Sun, Microsoft, and Netscape) to establish an electronic connection between his/her local client computing system, and a remote server system located at an ISP (Internet Service Provider). After such connection is made, the user can then perform a number of operations through the browser, including such tasks as uploading/downloading files (including text, graphics, audio, video, etc.) and even executing programs located on such remote server. The ability to locally execute programs retrieved from a remote ISP is in fact one of the greater attractions and promises of the WWW. By having a repository which is accessible to millions of users simultaneously, program authors have an opportunity to expand the distribution and use of their products to a level far beyond that previously attainable. To avoid cluttering the user&#39;s local computing system with extraneous program and associated support files, and more importantly so as to provide a measure of protection and security to such user, many of such programs are now being implemented using a language known in the art as Java®, and, in particular, using programming tools known as “applets.” Java® applets are akin to Java® applications, but the former are specifically designed to interoperate with graphical user interfaces such as the conventional browsers mentioned above. Applets are extremely popular programs today also due to the fact that they provide program authors with the tools to create multi-media capable programs quickly and easily. 
   The ease of access to remote programs, however, also increases the possibility of potential security/privacy breaches at the user&#39;s local computing system. There is simply no practical method for a user to monitor the behavior of a remotely retrieved program to ensure that it is not improperly loading data to the user&#39;s system, or worse yet, capturing or altering private data from the user&#39;s local file system in his/her computing system. To address this concern, the authors of Java® intentionally constrained applets to operate in what is conventionally known as “sand box.” In other words, applets were imbued with substantial functionality, but they are not permitted, for example, to do such things as read or write from file systems outside their own domain (usually the file system of the remote server). So, in the case of a remotely downloaded applet embodying some code which the user desires to execute, such applet cannot read or write to the user&#39;s local file system. For a discussion of this limitation of applets, please see “An Introduction to Computer Science—Using Java” by Kamin et. al., McGraw-Hill, p. 345 (1998). Another limitation, of course, is the fact that an applet cannot make use of data structures (such as graphics file formats for example) that are incompatible or unreadable with the browser within which such applet is executing. 
   Heretofore this limitation on applets has not posed a substantial barrier to the use of applet based programs on the WWW, although some attempts have been made to ameliorate the effects of this restriction. For example, some program designers have tried to exploit loopholes in the sandbox to trick the user&#39;s operating system into permitting the applet to gain local access and print a file on a local printer. These programming patches, however, are undesirable because they are system specific, and are susceptible to being closed down by Java® developers/standards enforcers. Others have suggested relaxing the constraints on applets which are known by the user to come from a verified “clean” source. By requiring an applet to pass through a certification process, some measure of security can be maintained. Again, nonetheless, such “exemption” process is also vulnerable to attack from would-be security invaders, and is therefore unattractive to users seeking the maximum security intended to be offered by the applet environment. It is also inconvenient to users, because they must still perform the task of evaluating whether a particular program is worthy of certification. This, too, reduces the incentives for users to use the WWW, since it requires too much effort for the ordinary user to know what is safe and what is unsafe. 
   Despite the fact that such efforts have been limited in the past, applicant has realized that the need for a satisfactory solution to the applet limitation is more crucial now. The inability of an applet to print to a local printer, for example, means that a local user is unable to capture his/her local input and/or contributions to an applet program displaying a remotely retrieved file. This limits the user&#39;s enjoyment of the program, since any contributions are lost once the browser program is closed. For example, a user who has used an applet in his/her browser and accessed a stock price chart located on a remote server, can make annotations, mark-ups, etc., and see such contributions on a display screen. They cannot, however, print a hard copy of such image, and again this reduces significantly the user&#39;s enjoyment and the utility of such program. 
   SUMMARY OF THE INVENTION 
   An object of the present invention, therefore, is to provide a system and method for permitting a local resource constrained software routine running on a local client system to circumvent such restrictions by exploiting resources at a remote server location; 
   Another object of the present invention is to provide a system and method for permitting a user of a locally executing client internet browser to manipulate and perform operations on files containing a mixture of local and remote server data; 
   A related object of the present invention is to provide a system and method for permitting a Java® applet to be able to emulate local file type functionality to a user while still complying with applicable security restrictions on such types of routines when running on a client machine; 
   Yet another object of the present invention is to provide a system and method for transferring data between a local computing system and a remote server so that file access privileges on the latter can be exploited by a program running on the former; 
   A further object of the present invention is to provide a system and method for permitting a user to engage in an interactive session during which they may modify content of data files from different remote sources, and still be able to capture and preserve such efforts in a local file system of the user&#39;s computing system; 
   Another object of the present invention is to provide a system and method for a remote server to engage a user to perform the above mentioned objectives. 
   A data capture program of the present invention is characterized generally by the fact that it is restricted from accessing a first local file system, but does have access rights to a second file system at a separate computing system. When program data is generated during an interactive on-line session that cannot be transferred to such local file system, the program instead transmits such program data from the local computing system to the second file system. The data capture program is further configured to interact with a browser on the local computing system, which browser has access rights to the local file system. In this manner, the browser program can then access the program data from the second file system, and transfer the program data to an output and/or storage device in the local computing system. 
   In a preferred embodiment, the program data is generally associated with modified file data resulting from modifications made by a user to initial data from an initial data file. These modifications could include additions, deletions, edits, etc., of any initial data file type preferably retrieved from the remote system, such as a file containing chart data, an audio file, a video file, a text file, etc. During the interactive session involving modifications to chart data, for example, any updates by the user are displayed dynamically in a first window on a display device for ease of use. Such modifications, because of restrictions on the environment in which such are created, cannot normally be saved to the user&#39;s local file system. Therefore, when the user wishes to save the results of such modifications, the modified file data is transferred as noted above to the remote server, where it is treated as described. Thereafter, the modified file data as retrieved from the remote server can be displayed in a second window to such user where it can be manipulated as desired by the browser program operating on the user&#39;s machine. In this manner, a user can preserve and capture the results of their efforts during such interactive session on a local computing system for future reference. 
   To transfer the modified file data from the local computing system to the remote server, an encoder is preferably used to compress the file data into a standard file format readable by the browser program. In the case of a visual image data, for example, the preferred approach is to convert such file into a GIF or JPEG formatted file. 
   The data capture program of the present invention is preferably implemented with one or more Java applets which are in the form of a remote program stored at a remote server. These applets are initially downloaded during the interactive session from the remote server but then execute on the user&#39;s local computing system within a restricted environment within the user&#39;s browser program. The remote program is preferably configured such that it interacts with the browser program and performs at least the following operations: 
   (1) retrieving an initial data file from the remote server for use during the interactive session; and 
   (2) displaying information relating to the initial data file in a display window visible to the user; and 
   (3) accepting modifications to such initial data file during the interactive session; and 
   (4) saving such modifications to such initial data file in an modified data file; 
   (5) routing the modified data file to the remote server; and 
   In this fashion, the modified data file can be retrieved by the user at a later time and saved to the local file system by the browser program as noted above. 
   To further assist the user, the remote program also provides user command functions in the display window, which command functions can be used to generate the modifications more easily. As the modifications are made, the user is preferably given feedback to confirm the same (such as with a line drawn on a chart for example). The invention is also flexible in that more than one initial data file can be loaded from one or more remote servers and modified, thus permitting essentially unlimited editing capability. 
   A remote server of the present invention is configured to permit a user remote from such server to engage in an interactive on-line session with such server using the aforementioned remote program. In this way, the server can interact with the local machine as described above. 
   In a preferred embodiment of the remote program permitting a user to annotate chart data with visual labels and descriptions, an interactive portion of such program has a first executable routine for processing initial data from the initial data file obtained from the remote server and for storing first image data associated with the initial data in a window image data buffer. The browser program then causes the local computing system to display the first image data in a window on a display to the user. A second executable routine generates modified data based on the user&#39;s modifying of the initial data with the visual labels and descriptions. A third routine then generates an modified data file based on the modified data, and then further transmits the modified data file to the remote server. Thereafter, the first routine, in cooperation with the browser, can also process the modified data file from the remote server, and thus the browser program can communicate the modified data file to a file system in the local computing system. 
   An interactive session between a local computing system and a remote server is therefore conducted in accordance with the present invention using the following preferred steps:
         (a) accessing a remote program located on the remote server using a browser program located on the local computing system;   (b) executing the remote program on the local computing system;   (c) accessing an initial data file from the remote server with the remote program for use during the interactive session; and   (d) displaying an initial display image based on initial data from the initial data file; and   (e) modifying the initial data;   (f) saving the modified initial data as modified data; and   (g) transmitting an modified data file corresponding to the modified data from the local computing system to the server; and   (h) accessing the modified data file from the remote server with the remote program;   (i) communicating the modified data file to a file system in the local computing system using the browser program.       

   In the above described method, the modified data is derived from an initial data file (which may include more than one initial data file) and supplemental data input under control of a user of the remote program. 
   In a further variation, the updated data file is image data compressed using an encoder which translates a pixel stream into a file format usable by the browser program or another program having access to the local file system. 
   Data transfers of the present invention are accomplished through an on-line connection between a local computing system and a remote server preferably using the following steps:
         (a) executing an interactive program on the local computing system, which interactive program coordinates with an on-line connection management program on such local computing system, and which interactive program further is restricted from accessing a local file system on such local computing system;   (b) accessing initial data information for use on the local computing system; and   (c) generating modified data information, which modified data information includes the initial data information and any additional data supplemental information added under control of a user of the interactive program; and   (d) saving the modified data information;   (e) transmitting the modified data information from the local computing system to the server; and   (f) accessing the modified data information from the remote server;   (g) communicating the modified data information to an output and/or storage device in the local computing system using the on-line connection management program.       

   Again, in a preferred embodiment, the modified data is compressed image data derived from dynamically modifying an initial data file. This image data is compressed using an encoder which translates a pixel stream into a file format usable by the second program. Nonetheless, the initial data file can be in a graphics file format, an audio file format, a text format, a video format, or some combination thereof. 
   An interactive, on-line session of the present invention permitting a user to engage in an interactive on-line session with a server using a remote program downloaded from the server but executing on the user&#39;s local computing system, and wherein the remote program is restricted from accessing a file system on such local computing system, is accomplished as follows:
         (a) coordinating communications between the server and a browser program also executing on the user&#39;s local computing system during the interactive on-line session, the browser program further including software routines for interacting with the file system on the user&#39;s local computing system; and   (b) receiving data at the server consisting of modified information transmitted from the remote program;   (c) creating an modified file for the modified information at the server, which modified file is accessible by the remote program;   (d) transferring the modified file to the local computing system so that the browser program can utilize the modified file;       

   In this manner, the browser program can thereafter transfer such modified file to an output and/or storage device in the local computing system, such as a printer, a local file system, etc. 
   Although the inventions are described below in a preferred embodiment, it will be apparent to those skilled in the art the present invention would be beneficially used in many environments where it is necessary to provide security constrained software routines with additional functionality. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram illustrating an embodiment of a system implemented in accordance with the teachings of the present invention; 
       FIG. 2  depicts in flow chart form the general method of operation of the system noted in  FIG. 1 ; 
       FIGS. 3A to 3C  illustrates the output generated by the present system and method as such would be seen on a display device by a user of such system; 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A preferred embodiment of a system  100  constructed in accordance with the present disclosure is shown in block diagram form in  FIG. 1 . A local client computing system  102  includes a number of components found in any typical contemporary computing system, including a processor  105  operable with a system code/data memory  110  (normally a DRAM), one or more input devices  115  (usually a keyboard, mouse, joystick or the like), a display memory  120  and associated buffer  121 ) (typically a supplemental fast VRAM or DRAM separate from system memory  110 ), a display  125  (preferably a CRT monitor, LCD panel etc.), one or more storage devices  130  (ordinarily a hard disk drive or other magnetic/optical based devices), an output device  135  (usually a printer) and an I/O interface  140  (preferably a high speed modem and associated drivers) for establishing an electronic connection  142  to the internet, an intranet, or other computer network. All of the aforementioned components are conventional, and it is understood that such computing system may range in complexity spanning the spectrum from a large multi-user mainframe down to personal electronic assistants. 
   Operating within code/data memory  110  under control of processor  105  is a browser program  150 , and an applet  160  executing within such browser. This applet runs in a standard Java virtual machine (JVM) within the browser. This operational relationship is denoted by browser program  150  enclosing applet  160 ; it will be apparent to those skilled in the art that this visual representation is merely intended for illustrative purposes, and does not purport to describe the entirety of the relationship between the browser and the applet. Moreover, since this relationship is well-known in the art, see e.g., the Kamins reference discussed above, it is not necessary to replicate such details here. Browser program  150  (preferably one of the more robust versions known in the art, such as Netscape Navigator or Microsoft Explorer) is configured to operate within system memory  110 , and is capable of interacting/communicating of course with the other components within system  102  in conventional fashion, as well as through internet link  142  with a remote server  180  located at an ISP site. Remote server  180  also includes many of the same components of system  102  (albeit in larger scale to accommodate the needs of several potential data requesters) such as an I/O interface  181 , a processor  182 , a server code/data memory  183 , and a storage system  185 . This system is used to store both an initial data file  186 , and an modified data file  187 , which items are discussed in more detail below. 
   Returning back to applet routine  160 , it can be seen in  FIG. 1  that this item includes applet code  162 , which is written in Java® programming code; a listing of the source code used in the present invention is appended to the end of the present disclosure as Appendix A. This Java® code can be executed by means of a Java® interpreter in browser  160  to carry out operations within system  102 . Applet code  162  has access to an applet data buffer  164 , which, as shown in  FIG. 1 , is designed to store incoming/outgoing data through internet link  142 . As seen in  FIG. 1 , initial window data  165 , as well as updated window data  166  are located and stored within such applet data buffer  164 . Finally, applet code  162  also has access to an associated applet window data buffer  166 , which it can use for painting a window on display  125  as explained further below. This buffer can be generated with conventional Java® programming tools, including, for example, the createlrnage( ) command to any desired size for the applet and application in question. The relationship between the various applet routines and resources can be gleaned further from the source code listing attached hereto, which includes all of the routines discussed herein except for the freeware programs noted below. 
   With the exception of the above details pertaining to applet  160 , the other circuitry, structures and routines embodied in the block diagram of  FIG. 1  are not material to the teachings of the present invention. These items are well-known in the art, and can be implemented by skilled artisans in a variety of ways. Moreover, it will be apparent to those of skill in the art that a number of conventional (but extraneous in this case) features of client system  102  and server system  180  have been omitted to better illustrate the present teachings. 
   As  FIG. 1  suggests, to maximize security and privacy for the user&#39;s local client computing system  102 , applet  160  is operationally restricted and has only limited access to components within system  102 . It cannot, for example, directly interact with a storage device  135 , or an output device  135  in order to create (or read) a file within local client system  102 . Nor can applet  160  operate to transfer a file directly to browser program  160 . This is an undesirable situation, since, as mentioned above, it is likely that many users in the future will download files from remote servers, modify such files, and yet not be able to do anything useful with them afterwards. For example, they will not be able to save such modifications for use with other programs on the user&#39;s computing system. It will be understood by those skilled in the art that Java language applets are only one form of programming which may be subject to such restrictions, and that the present invention is by no means limited to such specific contexts. 
   To overcome this limitation, applet code  162  of the present invention includes instructions which permit the local client computing system  102  of  FIG. 1  to carry out the method of the present invention as shown in flow chart form in  FIG. 2 . At step  205 , a user initiates an online session from his/her local client computing system  102  in conventional fashion, such as by dial-up or always-on access to an ISP. Browser  160  is then activated at step  210  to permit the user to see, interact and access other programs, files, etc. at step  215 ; such items may be located on the internet, including at a WWW compatible remote server  180  through an http link or the like. When the user desires to interact with a remote program on remote server  180 , one or more applets  160  necessary for operating such program will be transmitted downstream to the user&#39;s computing system  102  through link  142  at step  220  where they will be loaded into a code/data memory  110  for execution on local computing system  102  during step  225 . In a preferred embodiment, the remote program accessed and loaded by the user is located at a website maintained by Prophet Information Services at www.prophetcharts.com. This program is known as “Prophet Charts,” and generally includes such functionality as: (1) permitting a user to retrieve historical stock data from a file stored on a remote server; (2) placing such stock data in graphical form in a visible display window at the user&#39;s end; (3) permitting the user to annotate the chart with trend lines, labels, etc. to glean trading patterns, potential buy/sell opportunities, etc. Accordingly, in the event the user requests to see data associated with an initial remote data file  186  (FIG.  1 )—as for example, in the case of a historical chart showing the price of a particular stock for a particular period of time this file is retrieved by applet code  162  at step  230 . In this instance, as described above, applet  160  can access such data in file  186  because the latter is located logically in the same environment from which applets  160  are derived. To ensure that such data is usable by the user within system  102 , file  186  must be retrieved from server  180  in a format that is readable or decodable by browser  160 ; i.e., in text form, or some graphics form that is acceptable, such as GIF, TIFF, JPEG, or the like, depending on the particular browser program  160 . 
   In any event, initial data from file  186  is stored within Applet Data Buffer  164  at location  165  (as shown in  FIG. 1 ) where it is processed by applet code  162  and then placed into Applet window data buffer  166 . By coordinating with browser  160 , a graphical representation of initial data file  186  is then passed through display buffer  121 , where it then is placed in display memory  120  as noted in the dotted lines shown in  FIG. 1 . Subsequently, the applet window image data then also becomes visible to the user on display  125  as noted in step  235  of  FIG. 2 . 
   Up until this point, the above description has merely described the typical operation of any prior art Java® applet program loaded from a remote site onto a local client computing system. In the present embodiment, nonetheless, a number of additional unique operative steps are implemented to provide such program user with functionality not previously available. 
   Referring again to  FIG. 2 , the primary features, benefits, etc. of the present invention are based in large part on the operations carried out by applet code  162  beginning at step  240 . At that point in the routine, the user is permitted to interact with the data presented in the applet window image on display  125 . In particular, in a preferred embodiment, the user is allowed to add annotations to a graphical chart painted in such window. These annotations could include for example, data entered by the user manually from a keyboard/mouse  115 , additional data generated automatically by applet code  162  in response to a user command from such input device, or some other authorized and accessible data source for the applet. These modifications (including deletions, supplementations or embellishments) of the window image data are handled at step  245  until the user is finished and wants to do some other task (i.e., saving the modified image data, or perhaps working with another image). Again, with reference to  FIG. 1 , it is apparent that such additional data entered at step  240  can be passed through to applet  160  and processed by applet code  162  to update applet window data buffer  164 . From there it is passed on to display buffer  121  before it is used to update display memory  120  and the user&#39;s display  125 . Nonetheless, even though the window image data has been updated to include the efforts of the user to include such extra user generated data, it is not easily “capturable,” so as to help the user preserve their efforts because as it is stored it is not in a format that is understandable by browser program, and cannot be output by applet  160  to a storage device  130  because of the aforementioned security restrictions. 
   Returning to  FIG. 2 , the present invention permits a user to retain the results of their efforts, and capture their modifications to the initial data in the following manner. First, at step  250 , the user is prompted to determine if they would like to capture and preserve the modified window image data, i.e., such as by printing in hard copy form, or storing in some electronic form. If not, the user can retrieve a different file at step  230  or perform another operation of their choosing. Should the user desire to capture the updated window image, however, applet code  162  then proceeds at step  255  to convert such window image data into modified window data, which is stored in location  166  ( FIG. 1 ). First, the window image data is captured using a built-in standard Java® programming tool known as pixelGrabber. This routine captures the pixels from the Java® image and renders them into a one-dimensional array of integers. Each integer contains the red green and blue components of the color of that pixel. Then, this array is passed through a converter, where it is translated or converted into a standard graphics file format. This conversion is preferably performed by a pixel-to-gif converter to convert the pixels of the applet window image data into a Graphics Interchange Format (GIF) file. This conversion can be accomplished, for example, by a number of prior art programs, including by a freeware software routine authored by Jef Poskanzer entitled GifEncoderjava and available at any number of file sites on the Internet including at www.acme.com. It should be noted that the selection of the particular file format, and/or particular converter is not material to the present teachings, and the present invention is by no means restricted to any particular combination thereof. The only important parameter, as explained below, is that the modified applet window image data must be changed into a format that is compatible with browser program  160  as noted below. Alternatively, such format need only be readable by browser program  160  so that it can be downloaded and used by another program on the local computing system  102 . 
   In any event, after such conversion, at step  260  modified window data  166  is then uploaded by applet  160  to remote server  180 , where it can be written to remote data storage device  185  in a location  187  as a modified data file. This happens by opening a connection to a programming script running on web server  180  at the site the user is connected to. In the preferred embodiment, this is a script is implemented in “perl” which is a conventional, well-known scripting language commonly used by those skilled in the art. Basically, the perl script running on server  180  merely fetches the next available image number and writes the data from modified window data file  166  (containing the compressed array) to it, with a designation such as chartxxx.gif, where xxx is the next available number available on server  180 . Because this file is in compressed format, the transfer time between local computing system  102  and remote server  180  should be relatively reasonable. Furthermore, it is expected that improvements in high speed internet access will likely obviate any concerns about such types of relatively small scale data transfers. 
   At this point the captured user modified image data is now located on a server which can be accessed by browser program  150 . The perl script on server  180 , therefore, replies to applet  160  at step  265  with a URL indicating the location of the new file, such as “www.prophetcharts.corn/graphs/chartXXX.gif” and applet  160  then opens a new browser window, which can be displayed to the user on display  125 , which points to that image file. Because such file is also retrieved in a format usable by browser  160 , it can be manipulated and treated like any other file so that, for example, at step  270  it can now be saved in electronic form on local storage device  130 , or printed on a local output device  135 . The user can then proceed to retrieve additional data files at step  230 , or as noted above, simply go on to another operation. 
   As a housekeeping matter, and to save storage space, any such additional files stored on server  180  can be deleted after the user&#39;s session is over. It can be seen from the above description, therefore, that a server  180  is configured to permit a user remote from such server to engage in an interactive on-line session with such server using the aforementioned applet  160 . In this way, server  180  can interact and exchange data with local computing system  102  as described above, and preserve any contributions made during such session for the user&#39;s benefit. 
   While the above process appears somewhat circuitous, applicants have confirmed that it in fact proceeds very rapidly, and from the perspective of the user, does not involve an inordinate delay. Furthermore this process retains the integrity of the intended framework for Java® applets by ensuring that they do not access local resources. In this manner, users are guaranteed that the applets are kept in the Java® “sandbox,” and not permitted to perform operations that might compromise the user&#39;s privacy or security The present invention is extremely useful, therefore, for preserving and capturing the user&#39;s edits, modification, supplementations of an applet window&#39;s image data during an interactive session with a remote server, which, absent the present teachings, would be otherwise lost resulting in reduced productivity, utility, user satisfaction, etc. It is expected that the present teachings can be used in any number of Java® applet based programs, therefore, where it is desirable to permit the user to interact with applet data and yet still permit the user to exploit the use of local resources without the restrictions normally imposed on applet code. The present invention opens up a new realm of possibilities for WWW programmers, web-site operators, on-line vendors and users of the since it now allows data to be freely transferred and then modified under the user&#39;s control in a manner that preserves the user&#39;s contributions. 
     FIGS. 3A to 3C  are a series of screen shots illustrating the operation of the present invention as perceived by a user of a remote program which is used to launch locally running applets on the user&#39;s local computing system. In  FIG. 3A , a display  300  presents a user with a graphical interface  310  (generated by underlying browser  160 ) and an applet generated window image  320 , which window contains applet window image data  325  (derived from initial data file  165 ) as well as command buttons/activators  328  at the top of window  320 . The latter are used, as explained above, to permit a user to interact with the image presented in window  320 , so that, as seen in  FIG. 3B , such user can add additional information to such window data, remove information from the window, modify the existing data, etc. In this instance, the user has added a trend line  330  notation to the chart data image to reflect some additional perception by such user about such data that is not represented in the original data file  166 ; for example, an indicator showing the general trend of a stock price over time. Other image data annotations are of course possible, including descriptive labels, applet generated calculations, etc. A second data file containing data for a second stock could be subsequently loaded, for example, so that a composite image having data from both the first and second stocks could be seen in window  320 . 
   Assuming the user desires to capture the image data including the added trend line  330 , the conversion steps described above beginning with step  255  ( FIG. 2 ) are then performed as noted. Looking at  FIG. 3C , the returned modified data file  166  is then displayed in a graphics image format in a separate window  350  where, as noted earlier, it can be printed, saved, etc. by the user. 
   As alluded to briefly above, in another variation of the present invention, applet  160  can also permit such user to import an additional data file  166 ′ from server  180 , for example, representing data for a different stock so that a combined data image utilizing data from two different files  166  and  166 ′ can be observed simultaneously in an overlay fashion and manipulated by the user. Such data from the different files can be represented in different colors in applet data image window  320  to help the user differentiate the behavior of the two superimposed data sets for the selected two stocks. Such combined data from the two files (or more if desired) can then be converted into a suitable file format as explained above for the single image case, and then handled subsequently in the same manner. 
   In yet another embodiment, the modified data file can include information other than graphics data. For example, the user can download a standard audio file from the remote serve, edit such audio file using any conventional audio file editor, and then save any modifications in the same manner as performed above for the image data. Then, instead of receiving back a GIP file, a WAV file, MIDI file, etc., could be returned by the server. Standard encoders for compressing audio information can be used for generating the modified file at the local computing system before sending on this file to the server for later retrieval. Similar editing sessions with other types of files retrieved during an on-line session and manipulated by the user could be captured as well. In this manner, a user&#39;s contributions associated with an audio file, a text file, a video file, or any kind of multimedia file can be preserved and stored on the local computing system, even when using restricted code such as Java applets. 
   Although the present invention has been described in terms of a preferred embodiment, it will be apparent to those skilled in the art that many alterations and modifications may be made to such embodiments without departing from the teachings of the present invention. Accordingly, it is intended that the all such alterations and modifications be included within the scope and spirit of the invention as defined by the following claims. 
   Attached hereto is an appendix of the source code used in the various applet routines described above.