Universal Scanning Stand For Devices Equipped With A Digital Camera
One embodiment of a scanning stand for devices equipped with a digital camera comprising two inverted-V parts. One inverted-V part includes a sliding platform serving as a holder for a device equipped with a digital camera. Inverted-V parts are connected using nylon ribbons and the distance between inverted-V parts can be adjusted to accommodate documents of various thicknesses. A sheet of transparent acrylic or glass is included to provide means to flatten wrinkles or creases on documents and to straighten pages of bound material near the binding.
Copy stands for positioning a digital camera relative to the document to be copied are well known in prior art. Various book scanning mechanisms utilizing a digital camera to capture images have also been developed.
U.S. Pat. No. 6,540,415 describes a document capture stand that facilitates the use of a digital camera as a document scanner. This stand requires adjustment of the height and position of the camera to place it over the scanned document. This stand does not address imaging of bound documents.
U.S. Pat. No. 7,639,406 describes systems and methods of imaging printed material utilizing a V-shaped cradle and digital cameras. The system and methods described are designed specifically for bound documents. The system does not appear to be portable or inexpensive. It also appears that only specific digital cameras can be used with this system.
US Pat. Application No 20110267661 describes a book scanner that contains a V-shaped platform to support bound materials laid open and a depressor to depress pages of the bound material flat against the platform. This book scanner appears to utilize a specific type of a digital camera.
Devices for capturing images of documents using digital cameras heretofore known suffer from several disadvantages:
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- (a) Portable stands for capturing documents using digital cameras are not designed for imaging bound documents.
- (b) Stands for scanning bound documents are not very portable.
- (c) Scanning stands are not designed for use with a wide range of devices equipped with a digital camera.
- (d) The methods of capturing images of documents using these scanning stands rarely address post-processing of images using computer software like cropping to find page borders, rotation to position text properly for reading, re-sampling to make the image appear close to the natural size, re-ordering of pages etc.
In accordance with one embodiment the scanning stand comprises two inverted-V parts and a camera positioning platform and combines the document stand and a camera stand into one simple apparatus that is foldable for easy storage.
In the drawings, closely related figures have the same number but different alphabetic suffixes.
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- 1. Platform, front side of the stand
- 2. Platform, turning surface
- 3. Platform, imaging surface
- 4. Platform, rear side of the stand
- 5. Beam connecting bases of two platforms
- 6. Angle between platforms
- 7. A digital camera
- 8. Nylon ribbon
- 9. Sliding platform
- 10. Distance of up and down travel
- 11. Pegs
- 12. Gap between inverted-V parts
- 13. A book
- 14. Distance between the camera's lens and the imaging surface
- 15. Movement for closing platforms 1,2 and 3,4
- 16. Movement for closing the gap between tops of platforms 2 and 3
- 17. Movement for closing platforms 1,2 and 3,4, second method
- 18. Hole for inserting pegs
- 19. Cut-out in the platform
- 20. Tab
- 21. Vertical slots
- 22. Transparent sheet of acrylic or tempered glass
- 23. Page of a document
- 24. Small document
- 25. Direction of light
- 26. Field of view of the camera's lens
- 27. Direction of searching for the top edge
- 28. Direction of searching for the left and right edge
- 29-37 Steps of the scanning process
One inverted-V part of the stand, consisting of platforms 1 and 2 holds sliding platform 9 that serves as a holder for digital camera 7. This inverted-V part together with platform 9 constitutes the holding part of the stand.
The second inverted-V part of the stand consists of platforms 3 and 4—the page of the document that is imaged rests on platform 3. This inverted-V part is the imaging part of the stand and platform 3 is the imaging surface.
Platform 2 adjacent to the imaging surface 3 is the turning surface where already imaged pages of the document are turned.
In this embodiment platforms 1, 2, 3 and 4 have the same dimensions—33 cm wide by 28 cm high—this size of platforms is appropriate for imaging documents up to US letter paper size and international A4 paper size.
Platforms 1 and 2 are connected at the top in a hinged manner to allow folding and unfolding. Platforms 3 and 4 are also connected at the top in the same hinged manner to allow folding and unfolding. In this embodiment platforms 1, 2, 3 and 4 are matte black in color, in order to distinguish the platforms from the imaged document easily.
Bottoms of platforms forming each inverted-V part are connected by four removable beams 5 that slide into bases of platforms 1, 2, 3 and 4 when the stand is deployed for imaging document. Removable beams 5 are 33 cm long and 2.5 cm wide. The length chosen is the same as the width of platforms 1, 2, 3 and 4 in order to make it easy to store the beams together with the scanning stand once it is folded.
In this embodiment nylon ribbons 8 are permanently attached with glue to platform 2. Ribbons 8 pass under the base of platform 3 and through small slits close to the base of platform 3. The ends of ribbons 8 are attached to the surface of platform 3 using Velcro strips. The purpose of nylon ribbons 8 is to create or close opening 12 between two inverted-V parts of my scanning stand.
2*D14*tan(HAV/2)=MAX
D14 is distance 14, HAV is the horizontal angle of view and MAX is the max width.
In first step 29, document 23 is placed on this embodiment of my scanning stand between left and right ribbons 8.
In second step 30 a digital camera is placed on sliding platform 9 and the camera's zoom is adjusted. Field of view 26 of the camera's lens should cover as much as possible the width from the left edge of ribbon 8 on the left side of imaging surface 3 to the right edge of ribbon 8 on the right side of imaging surface 3. In this embodiment the width between outside edges of ribbons 8 is 30.5 cm, this width was chosen to support scanning of documents up to US letter size or the international A4 size. In most digital cameras the zoom adjustment is done in discrete steps, nevertheless the setting closest to covering the width between edges of ribbons 8 is the best choice.
In third step 31, the camera position is adjusted using the sliding platform 9 to align the bottom edge of the camera's lens field of view 26 with the bottom of page 23.
In next step 32 images of document pages are captured. A sheet of transparent acrylic or tempered glass is included with this embodiment of my scanning stand to facilitate imaging of bound documents or pages with wrinkles or creases. The pages are turned from imaging surface 3 to turning surface 2 to facilitate scanning documents with many pages.
During imaging of documents containing many pages, the bottom edge of the document page and the bottom edge of the field of view of camera's lens require re-alignment 34 every 50 pages or so by moving sliding platform 9 up to compensate for bigger distance from the page resulting from turning several pages since last adjustment.
With regards to imaging double-sided documents this embodiment is designed to capture images of all odd pages of the document first. Once all odd pages are captured 35, the document is opened on the first even page 36 to capture images of all even pages of the document. For documents with side-binding (e.g. books) this means that the document needs to be also rotated 180°. For documents with top binding (some notebooks), rotation is not necessary. When capturing of all document pages is completed 37, computer software is used to process captured images.
The following few paragraphs explain how the properties of this embodiment of my scanning stand simplify computer software for processing captured images.
When capturing double-sided documents, computer software re-orders and rotates all images automatically based on user selection of side-binding or top-binding of double-sided document.
In addition, computer software applies image rotation automatically to all document pages according to the rotation of the first page of the document. For instance, if the first page of the document needs to be rotated 90° clockwise, all remaining pages of the same document also need to be rotated 90° clockwise.
The placement of the document and adjustment of the field of view of camera's lens as explained above simplifies automatic cropping and re-sampling of the captured images by computer software.
Cropping of the captured page out of the background is simplified because the bottom edge of the page is aligned with the bottom of the captured image and because imaging surface 3 in this embodiment is matte black in color. Search for the left edge 28 of the page is performed near the bottom of the image by looking for the first group of non-black pixels, allowing a predetermined threshold for identifying black pixels, starting from the left edge of the captured image. Similarly, search for the right edge 28 of the page is performed near the bottom of the image by looking for the first group of non-black pixels starting from the right edge of the captured image. Search for the top edge 27 is done in the vertical strip of the captured image close to the left edge of the page.
Re-sampling of document images to, for instance, 200 dots per inch is easily done by computer software because the captured image covers the predetermined distance between ribbons 8—that is 30.5 cm (about 12 inches) for this embodiment. Each pixel of the image represents a square with sides approximately equal to 30.5 cm divided by the number of pixels in the horizontal line of the captured image. As a result the width and the height of document page 23 can be calculated by multiplying the corresponding width and height of the page in pixels by the calculated size of one pixel. Re-sampling of the image is important for applications where real dimensions of the object are needed to render a copy of the document properly. One example of such an application is internet faxing.
FIGS. 3A, 3F Additional EmbodimentsFrom the description above, a number of advantages of some embodiments of my scanning stand become evident:
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- (a) A wide range of devices equipped with auto-focus digital cameras can be used, including cell phones, tablets and web-cams.
- (b) Scanning of both bound and unbound documents is supported.
- (c) My scanning stand is foldable for storage or travel.
- (d) My scanning stand can be constructed using inexpensive materials with less labor than prior art examples of scanning stands.
- (e) The method for imaging of bound and unbound documents of various sizes is more practical than in previous art examples because it addresses a wide range of devices and a wide range of document types.
- (f) One or more aspects allow designing computer software in a manner that requires less computing power to process captured images of documents and removes mundane tasks that require software users' attention.
Accordingly, the reader will see that the scanning stand of the various embodiments can be used efficiently to scan single-sided and double-sided documents of various thicknesses, both bound and unbound and that it can be folded for storage and travel. In addition images of documents can be captured using various types of devices equipped with a digital camera. Furthermore, the scanning stand has additional advantages in that:
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- it can be manufactured using inexpensive materials like foam board, mat board or plastic;
- it enables practical methods for imaging of bound and unbound documents using various devices equipped with an autofocus digital cameras, including cell phones, tablets and web-cams;
- it allows to design more efficient computer software for processing images of documents;
Although the description above contains much specificity, it should not be construed as limiting the scope of the embodiments but as merely providing illustration of some of the presently preferred embodiments. Here are some examples of modifications:
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- the scanning stand can use different ways of holding the digital camera in place, such as elastic bands, materials with a high coefficient of friction, spring-based holding mechanism etc.;
- the size of the stand can be changed to allow scanning documents larger in format or in order to use cameras with a narrower horizontal angle of view;
- the width of the opening between inverted-V parts of the stand can be adjusted using Velcro strips etc.;
- sliding platform can use different means for attachment to the inverted-V part such as strong magnets, pegs, clasps etc.;
- only the imaging surface and the turning surface need to be solid surfaces, the remaining sides of the inverted-V parts can be made of wire etc.;
Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.
Claims
1) A scanning stand for imaging bound and unbound documents, comprising:
- (a) two inverted-V parts wherein the body of each said part has at least one surface and a hinged connection at the top and said hinged connection opens to form the same angle in both said parts,
- (b) a holder for a device equipped with a digital camera, and
- (c) first means for connecting said holder to at least one said part wherein said part with said holder attached to it becomes the holding part,
- (d) second means for placing a document on one surface of the second inverted-V part wherein said surface becomes the imaging surface and said second inverted-V part becomes the imaging part,
- (e) third means for turning pages of said document wherein said pages are turned from the imaging surface to the adjacent side of said holding part that becomes the turning surface,
- whereby when a device equipped with a digital camera is placed in said holding part, the body of said device is parallel to said imaging surface and the distance between the lens of said camera and the imaging surface is suitable for capturing images of document pages without the need for time consuming adjustments.
2) A scanning stand of claim 1, wherein the distance between bases of said imaging surface and said turning surface can be adjusted to match a document by setting said distance to the thickness of said document.
3) A scanning stand of claim 1, wherein the position of said device equipped with a digital camera placed in said holding part can be adjusted such that:
- (a) the vertical center line of camera's lens field of view is aligned with the vertical center line of said imaging surface, and
- (b) the bottom of said field of view is aligned with the bottom of a document page on said imaging surface.
4) A scanning stand of claim 1, wherein said imaging surface has vertical markers near its left and right edges that allow adjusting the width of the camera lens's field of view to match approximately a predetermined distance between said markers by selecting the zoom setting in the camera.
5) A scanning stand of claim 1, wherein said imaging surface has a horizontal marker approximately near its top that allows adjusting the height of the camera lens's field of view to match approximately a predetermined distance between the bottom of said imaging surface and said marker by selecting a zoom setting in the camera.
6) A scanning stand of claim 1, wherein said holder contains an opening that, providing said camera has a zoom lens, allows the zoom lens of said camera to extend without affecting the position of the body of said camera.
7) A scanning stand of claim 1, wherein said holder has the ability to hold bodies of various devices equipped with a digital camera in parallel to the imaging surface and said devices include cell phones, tablets and web-cams.
8) A scanning stand of claim 1, wherein said angle that said hinged connection open to is between 60° and 90°.
9) A scanning stand of claim 1, wherein bodies of said inverted-V parts after closing said hinged connection become flat parts which are easier to store and a sheet of solid transparent material placed between said flat parts is protected from damage or scratches.
10) A method for capturing a document using a digital camera, comprising the steps of:
- (a) providing said document is placed on a surface and said surface has a predefined color that is different from the color of the edges of said document,
- (b) providing said surface has marking objects near its left and right edges in a predetermined distance from each other,
- (c) providing the body of said camera is placed in parallel to said surface,
- (d) providing the center vertical line of the field of view of said camera is aligned with the center vertical line of said surface and the width of said field of view matches approximately said predetermined distance,
- (e) providing said document is placed on said surface between said marking objects such that the bottom of said document is aligned approximately with the bottom of said field of view,
- (f) capturing images of pages of said document with said camera so that the bottom of each page is kept aligned with the bottom of the field of view,
- whereby said images are stored in the memory of said camera and upon reviewing said images the edges of each captured page can be easily distinguished due to the difference in color between said surface and said edges and the width corresponding to a single pixel of each image is calculated by dividing said predetermined distance by the number of pixels in the horizontal line of the image.
11) The method of claim 10 wherein:
- (a) the left edge of the page is found by searching for pixels of approximately different color than said predetermined color along the bottom of the image starting from the left edge of the image,
- (b) the right edge of the page is found by searching for pixels of approximately different color than said predetermined color along the bottom of the image starting from the right edge of the image,
- (c) the top edge of the image is found by searching for pixels of approximately different color than said predetermined color in a vertical strip to the right of the left edge of the page starting from the top edge of the image,
- whereby knowing the position of all edges of the page the image is cropped easily and the dimensions of said page are calculated by multiplying the width and height of the cropped image in pixels by said width corresponding to a single pixel.
12) A method for capturing a document using a digital camera, comprising the steps of:
- (a) providing said document is placed on a surface and said surface has a predefined color that is different from the color of the edges of said document,
- (b) providing said surface has at least one marking object near its top edge in a predetermined distance from the bottom of said surface,
- (c) providing the body of said camera is placed in parallel to said surface,
- (d) providing the top edge of the field of view of said camera is aligned approximately with said marking object and the bottom edge of the field of view of said camera is aligned with the bottom of said surface,
- (e) providing said document is placed on said surface inside said field of view and the bottom of said document is aligned approximately with the bottom of said field of view,
- (f) capturing images of pages of said document with said camera so that the bottom of each page is kept aligned approximately with the bottom of the field of view,
- whereby said images are stored in the memory of said camera and upon reviewing said images the edges of each captured page can be easily distinguished due to the difference in color between said surface and said edges and the height corresponding to a single pixel of each image is calculated by dividing said predetermined distance by the number of pixels in the vertical line of the image.
13) The method of claim 12 wherein:
- (a) the left edge of the page is found by searching for pixels of approximately different color than said predetermined color approximately along the bottom of the image starting from the left edge of the image,
- (b) the right edge of the page is found by searching for pixels of approximately different color than said predetermined color approximately along the bottom of the image starting from the right edge of the image,
- (c) the top edge of the image is found by searching for pixels of approximately different color than said predetermined color in a vertical strip to the right of the left edge of the page starting from the top edge of the image,
- whereby knowing the position of all edges of the page the image is cropped easily and the dimensions of said page are calculated by multiplying the width and height of the cropped image in pixels by said height corresponding to a single pixel.
Type: Application
Filed: Feb 23, 2012
Publication Date: Aug 29, 2013
Inventor: Tomasz Wardega (Brecksville, OH)
Application Number: 13/402,871
International Classification: H04N 1/46 (20060101); H04N 1/04 (20060101);