Handwritten character recognition apparatus with an improved feature of correction to stroke segmentation and method for correction to stroke segmentation for recognition of handwritten character

• US 5,923,793 A
• Filed: 12/28/1995
• Issued: 07/13/1999
• Est. Priority Date: 12/28/1994
• Status: Expired due to Fees

• Current Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Original Assignee: NEC Corporation
• Inventors: Ikebata, Yoshikazu
• Primary Examiner(s): Shalwala, Bipin H.
• Application Number:
  US08/580,366
• Time in Patent Office: 1,293 Days
• Field of Search: 382/177, 382/178, 382/179, 382/185, 382/186, 382/187, 382/188, 382/189, 382/199, 382/200, 382/203, 382/309, 382/310, 382/311, 382/123, 345/173, 345/179, 345/326, 364/737, 707/530
• US Class Current: 382/311
• CPC Class Codes: G06V 30/333 Preprocessing; Feature extraction
• CPC Class Codes: G06V 30/36 Matching; Classification

Abstract

A method and apparatus for changing a segment of one or more strokes which are to constitute any of characters and signs by recognizing a relationship in the position between the frame encompassing the strokes previously hand-written and a stroke newly hand-written; judging whether there is any requirement for changing the segment by referring the above recognized relationship in the position to predetermined relationships; recognizing, if there is no requirement, the above newly hand-written stroke as a stroke which constitutes, alone or in combination with strokes to be hand written later, a character other than the character encompassed by the frame; ascertaining, if there is a requirement, the above newly hand-written stroke as any of one or more changing-instruction strokes which identify predetermined types of strokes for changing the segment; and changing the above segment according to the changing-instruction stroke.

Claims

1. A method of recognizing and implementing a frame or character correction instruction in a stroke that is newly hand-written with a tool on a table in a positional relationship to frames that are external to and encompass prior hand-written strokes that each constitute a character or sign, the method comprising the steps of:

recognizing the positional relationship between the frames and the newly written stroke by determining whether the newly written stroke'"'"'s start point and end point are positioned inside or outside of the frames and whether the newly written stroke crosses the frames;

when the positional relationship is that the newly written stroke'"'"'s start point is inside a first frame, recognizing the newly written stroke as a requirement to connect the first frame to a second frame when the newly written stroke'"'"'s end point is inside the second frame, and recognizing the newly written stroke as a requirement to add the newly written stroke to the prior hand-written stroke in the first frame when the newly written stroke'"'"'s end point is inside the first frame or outside all of the frames;

when the positional relationship is that the newly written stroke'"'"'s start point is outside all of the frames, recognizing the newly written stroke as a requirement to divide one of the frames when the newly written stroke'"'"'s end point is inside the one frame; and

implementing the requirement recognized in the newly written stroke by connecting the frames, adding to the character within one of the frames, or dividing one of the frames in the manner set forth in the instruction provided in the positional relationship of the newly written stroke to the frames.

2. The method as claimed in claim 1, wherein said recognition of the relationship in the position between said frames encompassing said strokes previously hand-written and said stroke newly hand-written is carried out with reference to X-Y coordinates which are set on said tablet.

3. The method as claimed in claim 1, further comprising the steps of:

ascertaining whether the start point and the end point are positioned outside of any of said frames, and the newly written stroke crosses at one point each of parallel two sides of a rectangular one of the frames; and

recognizing the newly written stroke as a requirement for deleting prior hand-written strokes encompassed by said rectangular one of the frames.

4. A method of recognizing and implementing a frame or character correction instruction in a stroke that is newly handwritten with a tool on a table in a positional relationship to frames that are external to and encompass prior handwritten strokes that each constitute a character or sign, the method comprising the steps of:

recognizing the positional relationship between the frames and the newly written stroke by determining whether the newly written stroke'"'"'s start point and end point are positioned inside or outside of the frames and whether the newly written stroke crosses the frames;

when the positional relationship is that the newly written stroke'"'"'s start point is inside a first frame, recognizing the newly written stroke as a requirement to perform a first corrective action when the newly written stroke'"'"'s end point is inside a second frame, and recognizing the newly written stroke as a requirement to perform a second corrective action different from the first corrective action when the newly written stroke'"'"'s end point is inside the first frame or outside all of the frames;

when the positional relationship is that the newly written stroke'"'"'s start point is outside all of the frames, recognizing the newly written stroke as a requirement to perform a third corrective action different from the first and second corrective actions when the newly written stroke'"'"'s end point is inside the one frame; and

implementing the requirement recognized in the newly written stroke by performing the first, second, or third corrective action in accordance with the instruction provided in the positional relationship of the newly written stroke to the frames.