A variety of devices have recently been developed to capture and process handwritten information. For example, devices have been developed to capture handwritten information and to convert the handwritten information into text utilizing various character recognition techniques. This text can then be further processed, transmitted or otherwise utilized in the same fashion as text that has been entered via a keyboard or the like. In addition, devices have been developed that capture handwritten information and thereafter maintain the handwritten information in handwritten form for subsequent transmission, display or the like. For example, the handwritten information may be a map, a diagram or other drawing, or a document that includes Asian language characters that are not easily entered using standard keyboards. As such, these devices generally maintain an image of the handwritten information for subsequent transmission or display.
The devices that capture handwritten information are computing devices such as a pen-enabled computing device. A pen-enabled computing device enables the user to input handwritten information with a writing stylus instead of a mouse or a keyboard. In this regard, a pen-enabled computing device includes a handwriting capture interface. The handwriting capture interface may be a touch-sensitive screen and an associated processor for determining the coordinates that have been contacted by a writing stylus. Alternatively, the handwriting capture interface may include an electronic writing tablet having an overlaid writing surface. The writing surface may include, for example, a blank sheet of paper or a preprinted form. By writing upon the writing surface by means of a writing stylus, the user generates a visible, or “written ink,” copy of the handwritten information. The handwriting capture interface of this exemplary pen-enabled computing device also includes a processor for detecting movement of the writing stylus upon the electronic writing tablet, i.e., relative to the writing surface, in order to capture an “electronic” copy of the handwritten information. Depending upon the design of the handwriting capture interface, the writing stylus may be a conventional pen or pencil, and the stylus may have a radio transmitter, a camera, an ultrasound transducer, any of a variety of magnetic or electric field devices, or any combinations thereof.
As will be apparent, the pen-enabled computing device may be capable of producing both an electronic ink and a written ink copy of the handwritten information. Since the writing stylus is generally capable of providing a written ink copy of the handwritten information on the writing surface, the user is automatically provided with a hard copy, or visual feedback. It is understood, however, that a written ink copy of the handwritten information may not be provided in some instances, such as those instances in which the handwritten information is only captured and stored by the pen-enabled computing device as an electronic copy.
Typically, a pen-enabled computing device senses the position and/or movement of the writing stylus with respect to the electronic writing tablet. Coordinates, such as the X and Y coordinates, representative of the position of the writing stylus at different points in time are stored by the pen-enabled computing device as the electronic copy of the handwritten data. The handwritten data is then often used for other purposes, such as by being incorporated into documents or being displayed. In order for the handwritten data to be subsequently utilized, it is sometimes translated from the handwritten form to text form. While text translation schemes may facilitate practical uses for the handwritten data, they are often not able to accurately translate the handwritten information. In addition, translation routines may impose additional processing and storage requirements that may disadvantageously add to the size and cost of the pen-enabled computing device. Moreover, certain handwritten information, such as maps, diagrams or other drawings, and documents containing Asian language characters, is highly usable in image form. Thus, the demand for pen-enabled computing devices that are capable of utilizing handwritten information for subsequent purposes, such as processing, transmission or the like, without requiring the handwritten information to first be translated into text form is increasing.
In a number of applications, the handwritten information that is captured by a pen-enabled computing device is designed to be transmitted to another, remotely located computing device. For example, a user may wish to provide a friend or co-worker in another town with a hand-drawn map. In these applications, the pen-enabled computing device is therefore one component of a larger system or network which permits the handwritten information that has been captured by the pen-enabled computing device to be transmitted to another remote computing device. In this situation, the pen-enabled computing device can include a transmitter for transmitting the handwritten data to a server, either via the Internet, wirelessly or according to some other transmission medium. The server then further distributes the handwritten data to the remote computing device, also via the Internet, wirelessly or according to some other transmission medium. The recipient can then display or otherwise process the handwritten data that has been received by the remote computing device.
Systems that include pen-enabled computing devices are desirably designed such that the resulting image of the handwritten information that is displayed for the recipient by the remote computing device accurately reflects the original handwritten information that was entered by the user and does so in a manner that is aesthetically pleasing. As such, the processor of some conventional pen-enabled computing devices smoothes the handwritten information prior to transmission of the handwritten information. As such, the image of the handwritten information that is eventually displayed to the recipient will appear to be less jagged and will appear to more accurately represent the handwritten information originally entered by the user. In order to smooth the handwritten information, the processor initially captures a plurality of coordinates representative of the position of the writing stylus relative to the electronic writing table at different instances in time, thereby defining one or more writing strokes. In order to display the handwritten information, the coordinate data is rendered into an image by utilizing line-drawing techniques known to those skilled in the art. The resulting image can be smoothed, such as by applying antialiasing techniques known to those skilled in the art. In this regard, antialiasing techniques adjust the gray-scale values of the pixels of the image in the vicinity of the lines such that the resulting lines appear to be smoother and have fewer sharp edges or corners. By way of example, the gray-scale values of the pixels along a line perpendicular to the line constructed by the line-drawing techniques can be modified to create a relatively smoothly shaped profile, as opposed to the relatively rectangular profile otherwise created by the line-drawing techniques. By repeating this process at each of a plurality of points along the line constructed by the line-drawing techniques, the image of the handwritten information can be smoothed.
Sometimes, the resolution of the handwritten information will also need to be changed from the resolution at which the handwritten information was captured to a new resolution at which an image of the handwritten information will be subsequently displayed. In instances in which it would be desirable to increase the resolution of the handwritten information, such as in instances in which the image of the handwritten information will be displayed in an enlarged manner by the remote computing device, a pen-enabled computing device may further process the handwritten information prior to its transmission to the remote computing device such that the resulting image of the handwritten information displayed by the remote computing device has a resolution that equals or exceeds the resolution at which the handwritten information was originally captured. In order to improve the resolution of the handwritten information, the processor of the pen-enabled computing device can create new points in the vicinity of the coordinates that define the handwritten information. For example, the processor can create new points in the vicinity of adjacent coordinates by means of known interpolation, approximation or curve-fitting techniques, such as cubic polynomial interpolation, approximation or curve-fitting, in order to effectively create additional coordinates near each original pair of adjacent coordinates. The image of the handwritten information provided to the remote computing device is therefore based not only upon the original coordinates captured by the handwriting capture interface, but also upon the additional coordinates created by interpolation, approximation or curve-fitting. As such, the resolution of the resulting image is effectively enhanced.
As will be apparent, the smoothing of the handwritten information and the creation of new points in the vicinity of the adjacent coordinates in order to improve the resolution of the handwritten information each impose substantial processing, memory and communications bandwidth requirements, thereby disadvantageously increasing the cost and decreasing the efficiency of the pen-enabled computing device and communications channel. The imposition of additional memory, processing and communications bandwidth requirements is especially disadvantageous for pen-enabled computing devices, however, since many pen-enabled computing devices are hand-held devices, such as personal digital assistants (PDAs), personal communications systems (PCSs), or other hand-held computing devices, which are designed to be as small, lightweight, and generally inexpensive as practical. Moreover, if the processor and/or memory of the pen-enabled computing device are undersized, smoothing of the handwritten data and creation of new points in the vicinity of adjacent coordinates may require inordinately long periods of time, thereby somewhat restricting use of the pen-enabled computing device. Additionally, the user of the pen-enabled computing device may be unable to anticipate the manner in which the remote computing device will display or otherwise utilize the handwritten information, thereby preventing the handwritten information from being effectively smoothed or the resolution of the handwritten information from being appropriately adjusted prior to transmission to the remote computing device.
With the proliferation of e-mail, instant messaging, and other electronic communication techniques, a variety of different types of information are routinely transmitted between parties. For example, information such as text, pictures, drawings, links to web sites and the like, is routinely transmitted from one party to another. In order to transmit both the handwritten as well as the additional information to a remote computing device, either in a single message or in separate messages, the memory, processing and communications bandwidth requirements of the pen-enabled computing device are further disadvantageously increased. Moreover, if the additional information relates to or is otherwise associated with the handwritten information and is transmitted in another message, the recipient must appropriately associate or relate the handwritten information and the additional information that are delivered via separate messages. While a variety of conventional pen-enabled computing devices are available for capturing and processing handwritten information, it would be desirable for the images of the handwritten information that are eventually displayed to be smoothed and to have improved resolution without unnecessarily increasing the processing, memory and communications bandwidth requirements and, accordingly, the cost of the pen-enabled computing devices. Similarly, it would be desirable for a pen-enabled computing device to be capable of transmitting messages that include both handwritten information and some additional information without unnecessarily increasing the processing, memory and communications bandwidth requirements of the pen-enabled computing device.