Image analysis – Image sensing – Multiple scanning
Reexamination Certificate
1999-09-30
2004-04-13
Couso, Yon J. (Department: 2624)
Image analysis
Image sensing
Multiple scanning
C382S255000, C358S474000
Reexamination Certificate
active
06721465
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a non-contact image reader for reading, recognizing, and checking information, such as document information written on a medium, such as paper, containing printed characters and figures, images, or stamped prints, and inputting the information as image data. The present invention also relates to a document information correction device using the non-contact reader, a control system suited to the device, and a system using the device.
Image input devices, which are commercially available at present, include a flat bed scanner, a sheet scanner, a digital camera, and a camera for paintings and calligraphic works. However, with respect to the currently available flat bed scanner, although the resolution of this device is high, the required installation area is large and the reading speed is low; and, with respect to the currently available sheet scanner, although the required installation area is small, it can read only data on documents in sheet form. With respect to the camera for paintings and calligraphic works, although the resolution thereof is high and some cameras for paintings and calligraphic works can read solids, the device typically is large in scale and the cost thereof is high. As mentioned above, these devices have merits and demerits, and, therefore, they do not completely satisfy the needs of all users.
For purposes of reading documents in a non-contact manner, there are methods, for example, as described in Japanese Patent Application Laid-open 8-9102 (Document 1); Japanese Patent Application Laid-Open 8-274955 (Document 2); Japanese Patent Application Laid-Open 8-154153 (Document 3, Mirror); Japanese Patent Application Laid-Open 8-97975 (Document 4, Book copy); Japanese Patent Application Laid-open 10-13622 (Document 5, White board); and Japanese Patent Application Laid Open 9-275472 (Document 6, Active illumination).
As related references, there are Matsuyama et al., “Edge detection using multifocus images and distance measurement”, Electronic Information Communication Society Journal, Vol. J77-D-II, pp. 1048-1058, 1994, (Reference 1); Kodama et al., “Emphatic acquisition of total focus images using generation of optional focus image generation off-focus images including the parallax from a plurality of images different in focus”, Electronic Information Communication Society Journal, Vol. J79-D-II, No. 6, pp. 1046-1053, 1996/6, (Reference 2); and Seong Ik CHO, et al, “Shape Recovery of Book Surface Using Two Shade Images Under Perspective Condition”, T. IEE JAPAN, Vol. 117-C, No. 10, pp. 1384-1390, 1997 (Reference 3).
The digital camera is superior from the aspect of easily inputting images. However, when the digital camera is used as an image input device for a document, because all information, such as characters, figures, and images, printed on the image plane, such as the surface of a paper, is important, in order to read the information precisely, it is necessary to place the object to be read in an ideal plane state as much as possible and to image the object with the camera precisely positioned opposite the face of the object.
Various proposals for correcting an image which is being read with a camera and which is not positioned precisely opposite to the face of an object being viewed from the front have been made. For example, in Japanese Patent Application Laid-Open 9-289611, there is disclosed a digital camera which is capable of correcting a slant image of an object to produce a pseudo-front image.
However, it is difficult to always keep a medium, such as paper in a flat state, and, actually, the paper is often uneven. When imaging such a paper surface, the conventional flat bed scanner prevents deformation of the image by pressing the paper surface onto a reading surface, such as glass, in order to input the image in a state free of irregularities.
Furthermore, an information correction process for reading a document, referring to a data base for other information, which is not included in the document, and adding the other information to the document, as described in, for example, Japanese Patent Application Laid-open 10-99791, “Method for processing change of address of distribution article”. In this information correction process, the destination information described on a distribution article is read, the distribution original data base is referred to, and when address change information is registered, the old address is converted to the changed address, and the changed address and name are output to a transfer label. It is described in the patent application that by doing this, the hand work of an operator can be reduced.
SUMMARY OF THE INVENTION
However, in the aforementioned conventional examples, it is a premise that a document on an image plane is read almost from above (Documents 1 to 3) and cannot be read from a free position.
A proposal to correct the measuring position by reading a calibration marker (Document 5: white board) has been made. However, a problem arises in that the operation is complicated.
Also, with respect to measurement of the distance to the reading surface from a sensor, the viewing of an observation article sideways (Document 4: book copy), the use of active illumination Document 6: active illumination), and the use of a stereo-camera have been proposed. However, a problem arises in each of these techniques in that the accuracy is bad and the cost is high.
A proposal (References 1 to 3) that the front image is restructured from the obtained distance data has also been made. The simulation by a computer shows that it is necessary to improve the processing speed to make this proposal practicable as an actual product.
When a conventional flat bed scanner is used, the scanning of the reading head takes a lot of time, and when there are many objects to be read, reading requires a lot of time. There is a limit to the reading environment, and the reading position and size are limited. Furthermore, a flat bed scanner is typically large in cross direction, so that installation of the equipment requires a large area.
According to Japanese Patent Application Laid-open 10-99791, the correspondence of postal articles with changed address labels is realized only in a particular sequence, and so a problem arises that, if the sequence of distribution of the articles is broken for any reason, the required correspondence between the articles and the labels cannot be obtained.
An object of the present invention is to provide a non-contact image reader for reading characters written on the surface of a folded form or a thick book in a good operability state and on a high image quality basis.
An another object of the present invention is to provide a non-contact image reader which is simple and has a high degree of freedom.
Still another object of the present invention is to provide a digital camera for use instead of a flat bed scanner and for reading, in this case, even a document or an image which is easily folded, as plane image data.
A further object of the present invention is to provide a document correction device for preventing a mistake in a corresponding relationship when additionally recording a change of address and for returning information on the distribution of an article and performing an effective operation.
To solve the aforementioned problems, the present invention comprises a reading unit for reading images, a reading condition changing unit for changing the reading conditions of the reading unit, a storage unit for storing at least two read images which are read under at least two different reading conditions, and an image correction unit for composing at least two read images and for developing them on a plane.
By reading an image while changing the reading conditions like this, it is possible to analyze the displacement of the image and measure the distance. The image can be developed on a plane from the distance. It is also possible to read not only the upper part of a document, but also to read the other portions at various angles. Therefore, it is p
Enomoto Shunichi
Kanou Mitsunari
Kawaoka Akihiro
Konishi Yoshiharu
Nakamura Toshiaki
Antonelli Terry Stout & Kraus LLP
Couso Yon J.
Hitachi , Ltd.
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