WO2001054394A2

WO2001054394A2 - Digitally archiving with metadata analog records captured by camera at optimized resolution

Info

Publication number: WO2001054394A2
Application number: PCT/US2001/001728
Authority: WO
Inventors: Richard J. Laxman; Barry R. Urry; Herbert J. White; Andrew J. Neilson
Original assignee: Intellectual Reserve, Inc.
Priority date: 2000-01-21
Filing date: 2001-01-19
Publication date: 2001-07-26
Also published as: WO2001054394A9; WO2001054394A3; AU2001227956A1

Abstract

A method and system for optimizing the conversion of analog records to digital format are disclosed. The method includes: examining related analog records to be archived, analyzing an information detail selected from a worse case sample of the examined analog records, imaging the information detail with a digital imaging device (10) for a pixel sequence, optimizing the resolution of the pixel sequence, capturing the analog record with the digital imaging device (10), and saving the captured record as a digitally archived record. The steps of capturing the analog record and saving the captured record can be repeated for each page within the related analog records without having to re-optimize the resolution of the digital image prior to recording and saving. The pixel sequence is based on a pixel-per-line sequence (PPLS) ranging from 3 pixels to 10 pixels, and is especially based on a PPLS range of 3-4 pixels.

Description

DIGITAL CAMERA PROCESS

BACKGROUND OF THE INVENTION The present invention relates generally to digital imaging archiving, and, more specifically, it relates to improving the resolution and reducing the storage size of digitally imaged records and incorporating metadata to identify such records.

Capturing and recording documents for preservation is well known in the arts. Specifically, records, such as birth records, marriage records, church records, diaries, and other authored works, are maintained in alternative forms to preserve them for research and historical value. These alternative forms include microform, analog recording such as video tapes and audio files, and digital image or document capture.

One solution to the problem of image and information deterioration over time is to capture information in a digital format that can be manipulated and handled without losing critical information. Unfortunately, the ability to capture the full details of a given image are limited by the storage capabilities and storage capture or image capture tools currently available. These materials typically are used for archival purposes to store important historical documents for research and access without continually perusing the original document. Once the documents are authenticated, they can be used by researchers as genuine documents from which valuable information may be extracted. For example, genealogical and family history research is an important undertaking conducted by many. Genealogical research requires access of historical documents, such as town records, old diaries, church records and other writings, such as birth, marriage, and death certificates, among others. To allow access to these important historical documents routinely leads to deterioration of the originals. Capturing the information in analog form for reproduction is one solution, however, this still limits the number of views that can be made of the particular document. Thus, digital capture and storage of original documents allows greater access to the general population ithout damaging the original document as it can be reproduced quickly and without limit. The digital capturing of analog information allows it to be distributed more rapidly to many users. Unfortunately, digital capture also suffers particular problems. One of these problems includes not always able to maintain the full resolution of the original image so that no detail is lost. With historical records, mostly handwritten, the information stored in the handwriting resolution must be maintained as accurately as possible, or misinterpretation can occur when viewing the digitally rendered image. The greater the resolution, the greater the reliability in reproducing the document in its original form. This greater resolution allows the user of the information to glean critical information within the document. This information can include birth dates, marriage dates, dates of death, family names, ages, and other information that is useful to those in the genealogical and family history arts. It should be also known that this information would be useful for others outside these areas, such as in banking, science, and history, which all rely upon old documents for historical and analytical purposes.

Thus, there is a need in the current digitally archiving arts to capture digital images of analog records in as accurate a manner as possible and to provide information that can be used to authenticate the captured image at the time of image capture for reliability and accuracy required by later users, typically genealogists, scholars, and historians.

SUMMARY OF THE INVENTION

According to the present invention, a method and system for optimizing the conversion of analog records to digital format are disclosed. Within the method, the steps include: examining related analog records to be archived, analyzing an information detail selected from a worse case sample of the examined analog records, imaging the information detail with a digital imaging device for a pixel sequence, optimizing the resolution of the pixel sequence, capturing the analog record with the digital imaging device, and saving the captured record as a digitally archived record. The steps of capturing the analog record and saving the captured record can be repeated for each page within the related analog records without having to re-optimize the resolution of the digital image prior to image capture and saving. The pixel sequence is based on a pixel-per-line sequence ranging from 3 pixels to

10 pixels, and is optimally based on a PPLS range of 3-4 pixels.

The method further includes the step of providing metadata associated with the analog record for archival and authentication purposes. The metadata is digitally saved with the digitally archived record. The metadata includes, among other things, data identifying the origin, the source, and the date of capture and storage of the analog records.

The system utilizes a platform with a digital imaging device, such as a digital camera, mounted to the platform, to capture the analog records and store them in digital form. A computer system couples to the digital camera and stores the digital image along with the relevant metadata associated with the analog record stored in digital form.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are, therefore, not to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

Figure 1 illustrates an image capture system in accordance with the present invention; Figure 2 illustrates a sample section with corresponding enlargement of a document to be captured with the system of claim 1 ;

Figure 3 illustrates an enlargement of the selected sample section of Figure 2; Figure 4 illustrates a digitized representation of the selected sample of Figure 3; Figure 5 illustrates a pixelization of an image element from a sample document as identified for capture optimization in accordance to the present invention;

Figure 6 illustrates a metadata template for identifying captured documents in accordance with the present invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the system and method of the present invention, and represented in Figures 1 through 6, is not intended to limit the scope of the invention, as claimed, but is merely representative of embodiments of the invention. The specific embodiments of the invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.

The following is a description of the digital imaging system 10, which is depicted in Figure 1 in accordance with the present invention. The digital imaging system includes several elements, which are utilized to maximize throughput and storage capability. The first element is camera 12, which captures the image for digital storage within digital imaging system 10. The imaging device or camera 10 comprises an area CCD or sensor array. The present embodiment utilizes a sensor array having a resolution of 2048 pixels by

3070 pixels or higher. The size of image files generated by the camera 12 are about 6.0 MB for grayscale, and 18.0 MB for color or larger. Camera 12 connects to a computer system 14, which has the ability to process large data files typically involved in capturing and manipulating image information. In this example, the computer has a Pentium III processor operating at 700 MHz. The computer system further includes 512 MB of RAM, and also includes three hard drives of large proportions, typically 18 GB to 36 GB, each. Computer system 14 further includes data entry means, such as a keyboard and mouse and a display 18. The computer system operates on Windows NT, although other computer systems or operating systems, or both, may be freely substituted. A foot control 30, coupled to computer 14, allows the operator to operate and control the camera via foot controller 30, thus freeing the user's hands to manipulate the article being captured or to enter data in computer 14 via the keyboard.

Camera 12 mounts above a platform 16, upon which articles 18 are placed so they can be digitally imaged. Camera 12 is placed on a holder 20 can be height adjusted so that the document to be captured fits within the camera's viewing angle. The adjustment can be manual or motorized. The system operator can use a switch to activate the motor to raise or lower the camera in position.

A lighting system 22 is provided above platform 16 to illuminate the article being imaged. Lighting system 22 typically includes a pair of fluorescent lights, which are placed on either side of platform 16 at 45 ° angles to the table for uniform lighting . The lights are daylight balanced. The lamps are selected to run cool. A light baffle 24 is provided to reduce the direct light intensity away from the operator's eyes and onto the article being imaged.. Platform 16 should be firm and stable so that unwanted vibrations will not distort the images captured by camera 12. In an alternative embodiment, platform 16 can be portable with folding and adjustable legs that can be elevated or lowered to a height appropriate for the operator.

Camera 12 utilizes a lens 26 and an RGB filter element 28 attached to the lens. Lens 26 is capable of taking full ratio images. In one embodiment, lens 26 is a 50 mm lens, but can be changed according to the needs of the operator. For example, wide angle and macro lenses can be used when desired. RGB filter 28 converts a grayscale image to color or RGB rendering.

The digital imaging system 10 further includes software to facilitate the images to be stored on the hard disk and later manipulated. Software enables the user to save particular files and edit them as necessary. Also, the software system allows the operator to calibrate camera 12 and control image exposure for optimal operation. The operator would select the exposure control either directly on the camera or tlirough computer system 14. The system allows the operator to access the camera exposure controls through a camera control window displayed by the computer system. The operator can set the gain, exposure, and intensity of the imaging system. The camera control window typically is a floating window that can be place anywhere within the viewing area by the operator. The exposure control allows the camera operator to regulate the shutter speed of the digital camera.

The software run on the computer system further allows the operator to select the entire document, or zoom to any portion on the document of interest. The zooming feature can be adjusted manually by the operator, or mechanically via a motorized zoom operated by the operator, or via direction through the computer. The system includes a zoom window that allows the operator to zoom in on a section of an image, and still allows the entire image to be viewed in the main viewing window. The zoom window appears by default when the program is initialized. By placing the cursor in the zoom window, and clicking the mouse button, it is possible to zoom in on the image. A histogram window is activated when selected and displays a histogram of the image recorded. A color calibration window allows the operator to view the color information of individual pixels within the image. The RGB calibration window can be selected by the operator and is used to calibrate the RGB filter attached to the camera lens. In a specific embodiment, the green filter is set to default and the red and blue values are corrected accordingly. The operator can also select a dithering algorithm to dither the image suitable to a particular image, or set of the images. Generally, no dithering is required for image capture .

When capturing images with the camera and storing them on the computer system, the camera operating system enables the user to enter metadata through a metadata configuration dialog box. The metadata configuration dialog box allows the camera operator to configure the image file names to meet any given metadata requirement. Inclusion of the elements defined in this dialog box are controlled by a log file dialog box.

During exposure, the operator can control the amount of light that is received by the digital camera in different ways. The shutter in the digital camera is a mechanical leaf shutter. It functions like the shutter of a normal camera. The shutter may also be an electronic LCD shutter. The amount of time that the light is allowed to strike the CCD array in the digital imaging devices is controlled by the shutter speed. When photographing images in color with the digital camera it is important to note that the camera actually captures three images-one through each of the red, green, and blue filters. When there is reference, however, to the shutter speed of the digital camera, only one value is given, typically at the green filter. The exposure times of the other two filters are based upon the shutter speed of the green filter. For general image capture, the shutter speed needs only be set once. There are, however, instances when the shutter speed needs to be adjusted to bring out the information in a document, or set of documents. These adjustments are well within the ability of one skilled in the art of photography.

Another way to control exposure is to control the amount of light that is allowed to pass through the lens to the sensor array. A lens aperture, or f-stop, is the means for this control. The lens used on the digital camera has a variable aperture control. Typically f-stop numbers are preceded by an "f" and are f5.6, f8.0, fl l, fl6, etc.. A relationship exists between the f-numbers. As the numbers gets larger, the aperture becomes smaller. The amount of light entering the lens decreases-by half-as a larger number is selected. This means that f8.0 allows half as much light to enter the lens as f5.6, but it allows twice as much light as fl 1. The software operating with the digital camera allows the operator to change the shutter speed and exposure values. The shutter speed or exposure value can be changed by the user by using a mouse to select arrow buttons that move the exposure or shutter speed up or down accordingly.

Generally, the operator will not need to change the f-stop of the camera lens. Currently, the lens is set at f5.6 for normal operation. There are applications, however, for having the f-stop set differently. The easiest way to change the f-stop is to remove the lens from the camera. When the f-stop is changed, typically it is necessary to change the shutter speed or exposure value. This is done to match the two for appropriate exposure. The relationship between aperture/f-stop, and exposure value is an inverse relationship. As the aperture gets smaller, the exposure value is increased.

The digital imaging processing system of the present invention is used to capture as accurate a depiction of the image 50, shown in Figure 1, as is possible. Often, there are elements within the image that are difficult to focus or select. In order to optimize the camera focus and take as accurate a picture as possible of the subject matter, the operator must perform an analysis of the articles to be captured. Specifically, the operator reviews selected samples of the entire material to be captured. At that point, the operator selects a region 52 in the sample to be digitally captured that is the least-resolved portion of the image in the whole image, but that carries relevant information within the image. For example, often, hand writing degrades over time and gathers dust that could be misinterpreted should the imaging system be automated to capture the image. The operator has the processing ability to discern more accurately and more consistently when a smudge is just a smudge to be ignored or is part of the writing and needs to be preserved as accurately as possible. The operator can evaluate the image for relevant information and exclude irrelevant information for greater accuracy.

Figure 3 illustrates a sample of the document 50 of Figure 2. The sample appears slightly grainy to the operator upon magnification. The digital camera thus focuses on particular pixels within the image. This causes problems during the actual capture of the image due to pixelization, which is shown in Figure 4. Because of the size of the pixels, the lens that is being used, and the thickness of the line, there is no clear transition between the line and the background. In the camera of the present invention, there is a 3-4 pixel transition from line to background (signal-to-noise) upon proper magnification and focus. To optimize and fully capture as much information as possible during digital imaging capture, it is necessary to consider the thickness of the line, the height of the camera, and the contrast of the image to an order to determine the number of transition pixels. If the page is "pure" white, the number of transition pixels is fewer and focusing is easier. If the page is not a clean page, however, and the writing is light or faded, focusing can be difficult. Another issue that complicates focusing is the shape of the letters. Vertical or horizontal lines within a letter offer the easiest objects on which to focus. "Round" letters are more difficult to use. An example of a "round" letter is shown in Figure 5 and has more defined pixilization due to it roundness.

The operator must consider several things when focusing the digital camera. The first is that the monitor generally does not display a real-time image; although a real-time image can be displayed in certain embodiments. The camera displays an image that has been captured and then processed. It is the equivalent of looking at the photographic print after it has been taken and developed. The shutter must have "snapped" and the computer process the image, before it can be displayed. In the continuous shutter mode capture, processing and image display take place every two seconds. Therefore, there is a delay from the time that the lens barrel is turned to the moment that the results can be viewed on the monitor. The second consideration made by the operator is that even if the image capture is in RGB color, the continuous mode, for focusing, shows a black and white image. As soon as the continuous mode is shut off and normal capture occurs, the image will be in color. In order to focus properly, the operator needs to magnify the image at least 300% to 500%. If the image is not magnified, the operator cannot see and assess the subtle characteristics of the line segments and the pixels. Additionally, the operator, during selection and capture of an image, zooms onto a character that appears in the image to select a pixel transition within the 3-4 pixel range to achieve optimal resolution. The magnification allows the operator to assess the line segments for proper resolution or pixels per line segment (P. P. L. S.). The operator focuses on the image and selects the thinnest line segment noticed in the image. This line segment should have three to four pixels for color or gray scale images.

If the line has fewer than three to four pixels, the operator needs to move the camera closer to the document or book for actual image capture.

For example, an image appears to be in focus when viewed at normal magnification. When the image is greatly magnify, however, subtle characteristics can be seen. The characteristics of an image that is out of focus is that it has low signal-to-noise ratio

(contrast), thus needing more pixels per line segment (a fatter line) that results in poor definition of the letter or object. A correctly focused image is shown in Fig. 3. A clear and distinct definition of the characters is achieved and sharp contrast is provided. When the document is viewed at normal magnification, the information is crisp and easy to read. The color balance of an image is affected by several different things at a time.

These include the color temperature of light falling on the object, any medium that the light test pass-through before striking the object, and others. At times, the operator will be required to photograph samples or documents under glass. Glass affects the color balance of the resultant images. Accordingly, the color cast imparted by the glass must be compensated for. This is done by changing the exposure factors for the RGB filter. The digital imaging processing system shown in Fig. 1 includes two sets of fluorescent lights that are balanced to approximate daylight color temperature. Color temperature is rated in degrees Kelvin. The fluorescent lights are rated at 5500 K.. Normal sunlight is rated at 7000 K.. To optimize the image capture, the operator must insure that there is no extraneous light falling upon the document to be captured. Any extraneous light falling on the document affects the color balance. Thus, only the fluorescent copy lights or the lights associated with the digital imaging system should be focused on the image to be captured.

The RGB filter portion of the digital camera allows the digital camera to capture information in color. The RGB filter, in this embodiment, utilizes a liquid crystal (LCD) element that changes color electronically. Normally, when the camera captures a single image, it is done in gray scale or black and white. When the camera is configured to capture color, the camera selects and makes three exposures, one through the green filter, one to the red filter, and one through the blue filter.

Since the different colors of the RGB filter have different light transmission values, the camera cannot be exposed to each of the filters for the same amount of time. Green has the highest transmission value while blue as the lowest transmission value. Accordingly, the blue exposure is open longer than the green. Once the three images are captured, the computer processes the information to create the final color image.

When the operator is capturing the digital imaging information of a given article or articles, it is necessary that all information about the article, such as a document or volume being imaged, be included correctly to avoid problems with the cataloging and indexing, and eventual use of the images. The information that is correctly gathered during the imaging process will be the basis for the future patron's ability to find and use the images. Much of the information about an imaging project that needs to be included in the image capture process is defined by established guidelines. The project name is predetermined as are the types of images that are to be captured. An example of a metadata field is illustrated in Figure 6.

The information that the operator will be acquiring, and configuring is called "Metadata." Metadata is descriptive information about any other information resource. Specifically, the captured images require information, or metadata, to identify and provide authentication of the particular information being imaged. This information is recorded in field 100 by the operator. Thus, metadata is data about data, or data about the digital images being imaged. The metadata describes aspects of information resources and helps others in accessing the information by providing such access to the information resources. Metadata may be categorized in many different ways. For example, metadata may be descriptive or highlight the discovery aspect of a particular image. Metadata may be directed towards the preservation of the information by identifying its original source 102, time of introduction into digital form 104, the author of the form 106 as well as the author of the document 108, and other bibliographic information.

Metadata typically includes various elements used to define and describe the captured data. For example, metadata elements for a category involving discovery of new information would include contributor, coverage, creator, date of authorship, description of image 110, format in which image is saved, title 112, language of original document, publisher of original document, relation of one image to others within the same subject matter, original source of document 102, subject of document 114, type of document 116, and which rights exist for access and manipulation or editing of the particular document.

Each metadata category would have different elements relevant to the particular subject matter of the category. In most cases, the elements will overlap from one category to another for bibliographic and authentication purposes.

The metadata is entered at the time an original document is about to be photographed or captured digitally. For a volume of information that is related, the metadata is simply established for the overall volume with specific reference being made for each page. It should be noted that when a blank page exists within a volume, rather than capture the entire image and take up valuable storage space, a marker is placed within the digital file indicating that a blank page exists at that point and highlights which page it is. This reduces storage space for an entire volume and also indicates to later users that although no information is displayed on that given page, there is no information being lost since none existed.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. What is claimed is:

Claims

1. A method of digitally archiving analog records in a manner that preserves information detail and minimizes digital information files size, comprising: examining an analog record to be archived; selecting an information detail from the examining step representative of a worse case sample of the entire record; surveying said information detail with a digital imaging device for a pixel sequence; optimizing resolution of the pixel sequence surveyed; capturing said record with said digital imaging device; and saving said captured record as a digitally archived record.

2. The method in accordance with claim 1 , wherein the pixel sequence is based on a pixel-per-line sequence ranging from 3 pixels to 10 pixels.

3. The method according to claim 1, wherein the pixel per line sequence is based on the range of 3 to 4 pixels.

4. The method according to claim 1, further comprising the step of providing metadata associated with the analog record for archival and authentication purposes.

5. The method according to claim 4 wherein the metadata is digitally saved with digitally archived record.

6. The method according to claim 5 wherein the metadata includes data identifying the origin of the analog record.

7. The method according to claim 5 wherein the metadata includes data identifying the source of the analog record.

8. A method of optimizing the conversion of analog records to digital format, comprising: examining related analog records to be archived; analyzing an information detail selected from a worse case sample of the examined analog records; imaging said information detail with a digital imaging device for a pixel sequence; optimizing resolution of the pixel sequence; capturing said analog record with said digital imaging device; and saving said captured record as a digitally archived record.

9. The method in accordance with claim 8, wherein the pixel sequence is based on a pixel-per-line sequence ranging from 3 pixels to 10 pixels.

10. The method according to claim 9, wherein the pixel per line sequence is based on the range of 3 to 4 pixels.

11. The method according to claim 8, further comprising the step of providing metadata associated with the analog record for archival and authentication purposes.

12. The method according to claim 11 wherein the metadata is digitally saved with digitally archived record.

13. The method according to claim 12 wherein the metadata includes data identifying the origin of the analog record.

14. The method according to claim 12 wherein the metadata includes data identifying the source of the analog record.

15. The method according to claim 8 further comprising the steps of: capturing the digital image of each portion of the analog records; saving the captured digital image of each portion of the analog records as a related file.

16. A system utilized to optimize the conversion of analog records to digital format, comprising: means for examining related analog records to be archived; means for analyzing an information detail selected from a worse case sample of the examined analog records; a digital imaging device capable of identifying a pixel sequence within the analyzed analog record; means for optimizing resolution of the pixel sequence; a digital image capturing device, coupled to the digital imaging device, to capture and store said analog record with said digital imaging device.

17. The system in accordance with claim 16, wherein the pixel sequence is based on a pixel-per-line sequence ranging from 3 pixels to 10 pixels.

18. The system according to claim 17, wherein the pixel per line sequence is based on the range of 3 to 4 pixels.

19. The system according to claim 16, wherein the digital image capturing device further provides metadata associated with the analog record for archival and authentication purposes.

20. The system according to claim 19 wherein the metadata is digitally saved with digitally archived record.

21. The system according to claim 20 wherein the metadata includes data identifying the origin of the analog record.

22. The system according to claim 20 wherein the metadata includes data identifying the source of the analog record.