JP2008301282A5 - - Google Patents

Claims (7)

An image processing apparatus that inputs a document image and extracts embedded watermark information from line spacing of character strings in the document image,
An input means for inputting a document image as image data;
Image reduction means for generating first reduced image data reduced in the first direction from the input image data;
Detecting means for detecting an end point of a character string existing area in the first reduced image data;
Setting means for setting a start point and an end point of scanning on two opposite sides of a quadrangle using the end points;
An information extraction unit that scans the reduced image data along a line segment connecting the start point and the end point set by the setting unit, detects a line interval of a character string, and extracts watermark information;
An image processing apparatus comprising: The image reduction means further generates second reduced image data reduced from the image data in a second direction orthogonal to the first direction,
When the effective character string line spacing is not detected by the information extraction means,
The detecting means detects an end point of a character string existing area in the second reduced image data,
The setting means sets a start point and an end point of scanning on two opposite sides of a quadrangle using the end points,
The extraction unit scans the second reduced image data along a line segment connecting the start point and the end point set by the setting unit, detects a line interval of a character string, and extracts watermark information. The image processing apparatus according to claim 1. The setting means, the image processing apparatus according to claim 1 or claim 2, characterized in that setting the midpoint of two opposing sides of the square with the end point as a start point and an end point of the scan. The image reduction means further generates third reduced image data reduced at a predetermined reduction rate in each of the first direction and the second direction,
The detecting means detects an end point of a character string existing area in the third reduced image data, and uses the reduction rate in the image reducing means and the coordinates of the end point to use the character in the first reduced image data. The image processing apparatus according to claim 1, wherein an end point of the row existence area is detected. A method for controlling an image processing apparatus that inputs a document image and extracts embedded watermark information from line spacing of character strings in the document image,
An input process for inputting a document image as image data;
An image reduction step of generating first reduced image data reduced in the first direction from the input image data;
A detecting step of detecting an end point of a character string existing area in the first reduced image data;
A setting step of setting a start point and an end point of scanning on two opposite sides of a quadrangle using the end points;
An information extraction step of scanning the reduced image data along a line segment connecting the start point and the end point set in the setting step, detecting a line interval of the character string, and extracting watermark information;
An image processing apparatus control method comprising: A step of generating, from the input image data, second reduced image data reduced in a second direction orthogonal to the first direction;
If the line spacing of valid strings in the information extraction step is not detected, and detecting the end point of the character string existing area before Symbol second reduced image data,
Setting a start point and an end point of scanning on two opposite sides of a quadrangle using the end points;
Scanning the second reduced image data along a line connecting the set start point and end point, detecting a line interval of a character string, and extracting watermark information;
Method of controlling an image processing apparatus according to claim 5, characterized in that it comprises a.   A program for causing a computer to execute each step of the control method for an image processing apparatus according to claim 5 or 6.