TW522716B - Correction method for imaging equipment - Google Patents

Abstract

The present invention provides a correction method used by an imaging equipment, which comprises at least a correction board not-embedded in the imaging equipment, and the correction board can be defined by the user himself and be arranged as pixels in a two-dimensional array, so as to prevent generating straight dark lines or bright lines on the output of the scanned document; next, capturing a plurality of data of the correction board with the imaging equipment; and, using the correction means, such as a low-pass filter, to process the information, and the correction means can be used to correct the aberration of the data.

Description

522716 V. Description of the invention (1) 5-1 Field of the invention: The present invention relates to a method for calibrating an imaging device, particularly a method for calibrating a scanner. 5-2 Background of the Invention: Scanners have the function of scanning documents, slides, and other images. In addition, there are many different uses; these well-known uses have gradually increased the proportion of scanners in the market. A common type of scanner is when you use one or more linear sensor arrays, in conjunction with a light source and optical components, to view a scanned document one line at a time. The image is moved by the linear sensor array in a direction perpendicular to the length of the linear sensor array at a constant speed relative to the scanned file, and scanned line by line to form a two-dimensional image data. As with the scanner above, slight differences in sensitivity will show the output signals of different sensing elements on the online sensor array. These differences in sensitivity come partly from the linear sensor array itself, and partly from uneven light sources, dust from optical systems or optical lenses, and so on. $ Therefore, before scanning, one-dimensional background data reading is usually performed at the position where the scan file is not placed, and the above-mentioned external factors are measured as the reference for correction; these one-dimensional background outputs are used as a set of one-dimensional correction values.

522716 V. Description of the invention (2) When scanning a document, these correction values are used to standardize the apparent sensitivity of the linear sensor array. However, in practical applications, various errors in the one-dimensional correction values are reduced. The quality of the image output. For example, a deviation value in the one-dimensional correction value comes from the presence of stains on the built-in correction plate or the failure of any sensing element. After scanning the file line by line, the output image is due to the correction value. The deviation value exists, resulting in a continuous dark or light streaks on the output image. Therefore, it is very important for the scanner to obtain correct and applicable correction values. 5-3 Purpose and Summary of the Invention: In view of the above background of the invention, the present invention provides a method for calibrating an imaging device; a calibration plate used in an imaging device can be specified by a user, rather than being built into the imaging device. Another object of the present invention is to provide a method for calibrating a scanner; the data of the calibration plate can be automatically corrected to avoid misreading of data due to several external factors, such as dust. It is yet another object of the present invention to provide a calibration method for a scanner; this calibration method can prevent straight dark lines from appearing on an output image of a scanned document

522716 V. Description of the invention (3) or exemption. According to the above-mentioned purpose, the present invention provides a calibration method for use in a camera device, which at least includes providing a calibration plate that is not built in the camera device. The calibration plate can be customized by the user and arranged in two. Dimensional array of pixels, which avoids streaks or bright lines on the output of the scanned document. Then, a plurality of information of the calibration plate is captured by a camera device; and a correction device (c 〇rrecti ο nmeans), such as a low-pass wave filter, is used to process the information. The correction device is used to correct the abnormal situation of the information (aberrati ο η ). 5-4 Detailed description of the invention: The correction method of the present invention can be widely applied to many camera devices and various scan files. When the present invention uses a preferred embodiment to describe the uninvented method, those skilled in the art should Some cognition is that many steps can be changed, and these general replacements undoubtedly do not depart from the spirit and scope of the present invention. Second, the present invention is described in detail with a schematic diagram as follows. When the embodiment of the present invention is described in detail, a schematic diagram showing a correction method is shown. A partial enlargement will be made for explanation, but this should not be used as a limited recognition. In this embodiment, an improved method for retrieving a document by a scanner is disclosed.

522716 V. Description of the invention (4) The output quality correction method at least includes: providing a correction plate, the correction plate is composed of a plurality of pixels (pi X e 1), a part of the pixels are arranged in a direction, The other part of the pixels are arranged in a vertical direction; the correction plate is scanned to retrieve the plurality of information of all pixels; and the information of the pixels is processed by correction means, which is used to correct the abnormal situation of the information (aberrati ο n). The first figure is a schematic diagram of the calibration process of the present invention. First turn on a camera, such as a scanner (step 10). For the calibration procedure of the present invention, the user may select a non-built-in calibration plate (step 11). One of the advantages of using a non-built-in calibration plate is that it saves space on the scanner. Another advantage is that it can be replaced with a suitable calibration plate to facilitate scanning of a wide variety of scanned documents. The use of replaceable calibration plates can avoid pixels with saturation saturation in the scanned file due to improper calibration plate comparison. Furthermore, unlike the one-dimensional calibration plate that is generally built into the scanner, the non-built-in calibration plate of the present invention is not limited to one dimension; that is, in two-dimensional directions (parallel and perpendicular to the linear sensor array Length) are all pixels and can be as large as the entire scan area. The advantage of using a two-dimensional calibration plate is to avoid straight dark or light streaks caused by misreading or abnormal situations when capturing the image information of the calibration plate. Moreover, the non-built-in calibration plate can be all black, all white, or even

Page 7 522716 V. Description of the invention (5) Hue. The user can select or change the correction plate of different tones to fit different scanned documents. Such a calibration plate can prevent the formation of saturated pixels in the scanned image of the scanned document. The saturated pixels on the scanned image originate from the signal value of the corresponding scanned file falling outside the value range of the traditional calibration board; the scanned image will be degraded due to the presence of saturated pixels. One of the advantages of the present invention is to provide a user to select an appropriate correction plate before scanning a document to further improve the quality of the scanned image. Then, the scanner captures the information of the non-built-in calibration board (step 12), and after analog / digital conversion, the signal corresponding to the non-built-in calibration board is first processed by low-pass wave (step 13). When the size of the correction plate becomes larger, the probability of abnormal pixels will also increase. In the present invention, the low-pass filtering can standardize the signal value corresponding to the abnormal pixel of the correction plate, thereby reducing the effect of the abnormal pixel. Then, the user can use the computer to view the output value of the calibration plate. In the present invention, the user can not only view the output value of the calibration plate, but also set the desired output value as the output value of the calibration plate by himself (steps 1 to 4). In the present invention, a settable output value corresponding to the correction plate provides a user with a more flexible operation ability when scanning a document. Furthermore, the user can store these set output values corresponding to the calibration plate (step 15). The second figure is a schematic view of a pattern of a calibration plate according to the present invention. A designed correction plate 21 has an n C π pattern with a different tone from the background.

522716 V. Description of the invention (6) After extraction, the output value is used as the correction value. Then scan a scan file 20 to get its output image. In an embodiment, the output image of the scan file 20 may be combined with the designed correction plate 21 to output an image 2 2 with a background output. The n C π pattern on the designed correction plate 21 can be used as the watermark of the scanned document 20. In the image 2 2 with background output, the hue of the n C π pattern can be darker or lighter than the pattern on the designed correction plate 2 1. Furthermore, the color tone of the portion where the original pattern of the scanned document 20 and the pattern of the designed correction plate 21 overlap is different from that of the scanned document 20. In this way, the designed calibration plate 21 not only provides the correction values required for scanner calibration, but also can be used as the background for the scan file 20 image output. The third figure illustrates the correction plate used in the scanner of the present invention. A reflective or transmissive scanner 30 is provided with a scanning work platform 34 for placing documents to be scanned. In the present invention, the size of a white (or black) correction plate 3 1, a uniform tone correction plate 3 2, or a correction plate 3 3 with a pattern “C” may be as large as the scanning work platform; thus, the present invention The scanner can capture all the information on the calibration board as the scanner's calibration data. The above are merely preferred embodiments of the present invention, and are not intended to limit the scope of patent application for the present invention; all other equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall be included in the following Within the scope of patent application.

522716 Schematic illustration of the present invention for a deeper understanding with the following diagrams. The first diagram is a schematic flow chart of the method of the invention; the second diagram is a schematic diagram of a corrected image of the method of the invention combined with a scanned image; and the third diagram Schematic diagram of the calibration plate of the scanner to which the method of the present invention is applied. The representative symbols of the main parts are: 2 0 scan file 21 calibration plate 22 image with background output 3 0 scanner 31 white (or black) calibration plate 3 2 uniform sentence tone correction Plate 33 Correction plate with pattern 34 Scanning table

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Claims (1)

522716 Case No. 901M648 6. Scope of patent application-1 · ^ 7. If the method of applying for the scope of patent application item 1, the basin includes-low-pass filter (10W-pass η; ~) described in 4 positive device to 8 :; = By: the scanner captures a document output quality correction method The edge method at least includes: a correction plate, the correction plate is composed of a plurality of pixels (pixels) a part of the elements arranged in a direction, ㈣ pixels The other P knife is arranged in the vertical direction; scan the front plate to capture the plurality of information of all these pixels; and use the correction means (c0rrection) to process the special signal of the pixels The correction device is used to correct the aberration of such information. Among them, the above-mentioned correction board includes at least all of the above-mentioned images. 9) The method of item 8 in the scope of patent application, including non-built-in scanner in. 10. The method according to item 8 of the scope of patent application, the element has a uniform hue. 12. The method according to item 8 of the scope of patent application, wherein the above-mentioned correction device includes a low-pass filter.