Portable scanning device

Abstract

A handheld optical scanner for capturing images of text from a rendered document is described. The scanner includes a package suitable to be held in a user's hand. The package contains an optical sensor that captures images of text from a rendered document. The package also contains a proximity sensor that determines when the optical sensor is within a predetermined distance and orientation of a rendered document. The package further contains a triggering mechanism that causes the optical sensor to capture an image of text from a rendered document when the proximity sensor determines that the optical sensor is within a predetermined distance and orientation of a rendered document.

1 . A handheld optical scanner for capturing images of text from a rendered document, comprising: 
 a package adapted to be held in a user's hand; and    inside the package: 
 an optical sensor that captures images of text from a rendered document;  
 a proximity sensor that determines when the optical sensor is within a predetermined distance and orientation of a rendered document; and  
 a triggering mechanism that causes the optical sensor to capture an image of text from a rendered document when the proximity sensor determines that the optical sensor is within a predetermined distance and orientation of a rendered document.  
   
   
   
       2 . The handheld optical scanner of  claim 1 , further comprising an output indicator.  
   
   
       3 . The handheld optical scanner of  claim 2 , further comprising a source of electrical energy used to power components of the handheld optical scanner, wherein the output indicator indicates that the electrical energy source has been exhausted.  
   
   
       4 . The handheld optical scanner of  claim 2  wherein the output indicator indicates that text recently scanned from a rendered document by the user should be re-scanned.  
   
   
       5 . The handheld optical scanner of  claim 2 , further comprising a data interface for exchanging data between the scanner and a host,  
     wherein the output indicator indicates whether the data interface is presently connected to a host.  
   
   
       6 . The handheld optical scanner of  claim 2 , further comprising a gesture detection subsystem for detecting the performance of a gesture with the scanner, wherein the output indicator indicates that the gesture detection subsystem has detected the performance of a gesture.  
   
   
       7 . The handheld optical scanner of  claim 2 , further comprising a memory that stores images of text captured from a rendered document, wherein the output indicator indicates that the extent to which capacity of the memory has been consumed.  
   
   
       8 . The handheld optical scanner of  claim 2  wherein the output indicator indicates that text recently scanned from a rendered document by the user is adequate to uniquely identify the rendered document.  
   
   
       9 . The handheld optical scanner of  claim 2  wherein the output indicator indicates that text recently scanned from a rendered document by the user is adequate to uniquely identify an electronic document from which the rendered document was rendered.  
   
   
       10 . The handheld optical scanner of  claim 2  wherein the output indicator is a visual indicator.  
   
   
       11 . The handheld optical scanner of  claim 2  wherein the output indicator is an audio indicator.  
   
   
       12 . The handheld optical scanner of  claim 2  wherein the output indicator causes the package to vibrate.  
   
   
       13 . The handheld optical scanner of  claim 1 , further comprising a memory for storing images of text captured from a rendered document.  
   
   
       14 . The handheld optical scanner of  claim 1 , further comprising: 
 a clock; and    a timestamping module that associates with each image of text stored in the memory an indication of a time obtained from the clock when the image of text was captured from a rendered document.    
   
   
       15 . A method in a computing system for determining completeness of a text capture from a rendered document, comprising: 
 monitoring the extent of a text capture being performed from the rendered document;    determining, during the monitoring, that the extent of the text capture has satisfied an objective; and    in response to the determining, indicating that the text capture is complete.    
   
   
       16 . The method of  claim 15  wherein the object that is determined to be satisfied is identifying the rendered document based upon the content of the captured text.  
   
   
       17 . The method of  claim 15  wherein the object that is determined to be satisfied is identifying an electronic document from which the rendered document was rendered based upon the content of the captured text.  
   
   
       18 . The method of  claim 15 , further comprising capturing the text by optically capturing an image of the captured text.  
   
   
       19 . The method of  claim 15 , further comprising capturing the text by capturing an audio sequence of a reader reading aloud the captured text.  
   
   
       20 . The method of  claim 15  wherein the indication comprises illuminating a completeness indicator.  
   
   
       21 . A method in a computing system for analyzing optically captured text, comprising: 
 identifying a sequence of individual symbols within the captured text;    initializing a sequence of values to contain a result, the sequence of values containing one value corresponding to each identified symbols in the sequence of identified symbols;    for each identified symbol, from the beginning of the sequence to the end of the sequence: 
 comparing the current identified symbol to identified symbols occurring earlier in the sequence to identify the first occurrence of the current identified symbol in the sequence;  
 if the current identified symbol does not occurs earlier in the sequence, storing a value in the result for the current identified symbol that is unique in the result;  
 if the current identified symbol occurs earlier in the sequence, storing a value in the result for the current identified symbol that as the same as the value stored for the first occurrence of the current identified symbol; and  
   outputting the result.    
   
   
       22 . The method of  claim 21  wherein the comparison is performed using image subtraction.  
   
   
       23 . The method of  claim 21 , further comprising comparing the outputted result to an index to identify an electronic document containing the captured text.  
   
   
       24 . The method of  claim 21 , further comprising: 
 transforming the outputted result into a textual form; and    comparing the textual form of the outputted result to an index to identify an electronic document containing the captured text.    
   
   
       25 . One or more computer memories collectively containing a data structure derived from a visual representation of text, the data structure containing a sequence of values each corresponding to one character in the visual representation of text, such that (1) for each group of visually matching characters in the visual representation of text, all of the characters of the group have the same value; and (2) each character's value reflects the number of different visually distinct characters that precede its first occurrence in the visual representation of text.  
   
   
       26 . One or more propagated data signals collectively conveying a data structure derived from a visual representation of text, the data structure containing a sequence of values each corresponding to one character in the visual representation of text, such that (1) for each group of visually matching characters in the visual representation of text, all of the characters of the group have the same value; and (2) each character's value reflects the number of different visually distinct characters that precede its first occurrence in the visual representation of text.  
   
   
       27 . A handheld optical scanner for capturing images of text from a rendered document, comprising: 
 a package adapted to be held in a user's hand; and    inside the package: 
 an optical sensor that captures images of text from a rendered document; and  
 a connector for connecting an accessory module to the scanner.  
   
   
   
       28 . The scanner of  claim 27 , further comprising a geographic location determination module that is capable of determining its own geographic location that is connected to the scanner via the connector.  
   
   
       29 . The scanner of  claim 28  wherein the geographic location determination module uses transmissions from global positioning satellites to determine its own geographic location.  
   
   
       30 . The scanner of  claim 28 , further comprising a memory that stores an image of text captured from a rendered document together with an indication of a geographic location determined by the geographic location determination module contemporaneously with the capture of the image of text.  
   
   
       31 . A method in a computing system for processing input collected by a handheld optical scanner capable of outputting an image of rendered text, comprising: 
 collecting a sequence of images captured from a rendered document by the handheld optical scanner;    for each of a plurality of adjacent pairs of images in the sequence, comparing the first image of the pair to the second image of the pair to identify a vector quantifying the translation of visual features in the first image of the pair to a new location in the second image of the pair;    accumulating a sequence of identified vectors corresponding to the order of the images in the sequence; and    analyzing the accumulated sequence of vectors to identify a gesture being performed with the handheld optical scanner.    
   
   
       32 . The method of  claim 31 , further comprising, before the analyzing, replacing a subsequence of two or more vectors adjacent in the sequence with a single composite vector.  
   
   
       33 . The method of  claim 31  wherein the identified gesture is generally circular.  
   
   
       34 . The method of  claim 31  wherein the identified gesture is a right-to-left capture of text earlier captured left-to-right.  
   
   
       35 . The method of  claim 34 , further comprising deleting the text captured in the right-to-left capture gesture from a buffer containing the text earlier captured left-to-right.  
   
   
       36 . The method of  claim 31  wherein the identified gesture is a back-and-forth rubbing gesture.  
   
   
       37 . The method of  claim 31 , further comprising: 
 accumulating a sequence of identified gestures; and    identifying a compound gesture comprised of the accumulated sequence of identified gestures.    
   
   
       38 . The method of  claim 37  wherein the compound gesture is identified using a tree data structure defining two or more different compound gestures.  
   
   
       39 . The method of  claim 38  wherein the tree is comprised of connected nodes, and each sub-root node corresponds to a gesture, and each root-to-leaf path through the tree corresponds to a compound gesture defined by the tree.  
   
   
       40 . One or more computer memories collectively containing a tree data structure that defines two or more different compound gestures, the tree comprising of connected nodes including a root node, each sub-root node identifying a gesture, and each root-to-leaf path through the tree defining a compound gesture comprising the sequence of gestures identified by the nodes in the path.