Method of using a fiducial in determining two media types of different lengths used on a flatbed scanner

Abstract

A method for determining a media size of a target scanned on the platen of the flatbed scanner using a fiducial placed on a backer of the flatbed scanner at a predetermined location. The fiducial is comprised of a plurality of objects, either placed in a predetermined pattern or randomly within a fiducial frame. A target is placed on the platen of the flatbed scanner and scanned along with the backer. The scanned image data of the target and backer is searched for the fiducial image. When the fiducial image is found, the media is selected to be of a first target type of a first media size, and, when the fiducial is not found the target is selected to be of a second target type of a second media size greater than the first media size.

What is claimed is: 
     
         1 . A method for determining a size of a target placed on a platen of a scanner having a scan lid with a backer mounted thereon providing a background for the target when the scan lid is in a closed position relative to the platen during a scanning operation, the method comprising:
 providing a fiducial on the background between a first location corresponding to an edge of a first target type of a first media size and a second location corresponding to an edge of a second target type of a second media size greater than the first media size;   placing the target on the platen;   when the scan lid is in the closed position, scanning the target and the backer to create a scanned image;   determining whether or not the scanned image includes an image of the fiducial; and   on determining that the scanned image includes the image of the fiducial, selecting the target to be of the first target type of the first media size.   
     
     
         2 . The method of  claim 1 , further comprising on determining that the scanned image does not include the image of the fiducial, selecting the target to be of the second target type of the second media size. 
     
     
         3 . The method of  claim 1 , wherein the determining includes searching the scanned image for the image of the fiducial in a direction from the first location to the second location. 
     
     
         4 . The method of  claim 1 , wherein the determining includes searching the scanned image for the image of fiducial using fast template matching. 
     
     
         5 . The method of  claim 1 , further comprising:
 extracting image data of a first resolution value from the scanned image within a search grid positioned around an expected fiducial image location between the first and second locations;   creating, from the extracted image data in the search grid, a set of N images of decreasing resolution values from the first resolution value;   determining whether or not a lowest resolution image in the set of N images includes the image of the fiducial; and   on determining that the lowest resolution image does not include the image of the fiducial, selecting the target to be of the second target type of the second media size.   
     
     
         6 . The method of  claim 5 , further comprising on determining that the lowest resolution image does not include the image of the fiducial, foregoing searching each of the remaining images in the set of N images for the image of the fiducial. 
     
     
         7 . The method of  claim 5 , further comprising:
 on determining that the lowest resolution image includes the image of the fiducial, searching the remaining images in the set of N images for an image of the fiducial; and   on determining that all of the remaining images in the set of N images include the image of the fiducial, selecting the target to be of the first target type of the first media size.   
     
     
         8 . The method of  claim 7 , wherein the searching the remaining images in the set of N images includes searching each of the remaining images in the set of N images one at a time starting from a lowest resolution image to a highest resolution image of the remaining images in the set of N images. 
     
     
         9 . The method of  claim 8 , wherein the searching the remaining images in the set of N images includes searching a next higher resolution image of the remaining images after the image of the fiducial is found in a lower resolution image prior to the next higher resolution image. 
     
     
         10 . The method of  claim 8 , wherein when the image of the fiducial is not found in a current resolution image being searched during the course of searching from the lowest resolution image to the highest resolution image of the remaining images in the set of N images, selecting the target to be of the second target type of the second media size. 
     
     
         11 . The method of  claim 8 , further comprising rescaling the search grid to a next higher resolution corresponding to a next higher resolution image of the remaining images in the set of N images to be searched, and repositioning and resizing the search grid using the fiducial image location at which the image of the fiducial was found in a lower resolution image prior to the next higher resolution image. 
     
     
         12 . A method for determining a size of a target placed on a platen of a scanner having a scan lid with a backer mounted thereon providing a background for the target when the scan lid is in a closed position relative to the platen during a scanning operation, the method comprising:
 providing a fiducial on the background between a first location corresponding to an edge of a first target type of a first media size and a second location corresponding to an edge of a second target type of a second media size greater than the first media size;   placing the target on the platen;   when the scan lid is in the closed position, scanning the target and the backer to create a scanned image;   determining whether or not the scanned image includes an image of the fiducial; and   on determining that the scanned image does not include the image of the fiducial, selecting the target to be of the second target type of the second media size.   
     
     
         13 . The method of  claim 12 , wherein the determining includes searching the scanned image for the image of the fiducial in a direction from the first location to the second location. 
     
     
         14 . The method of  claim 12 , wherein the determining includes searching the scanned image for the image of fiducial using fast template matching. 
     
     
         15 . The method of  claim 12 , further comprising:
 extracting image data of a first resolution value from the scanned image within a search grid positioned around an expected fiducial image location between the first and second locations;   creating, from the extracted image data in the search grid, a set of N images of decreasing resolution values from the first resolution value;   determining whether or not a lowest resolution image in the set of N images includes the image of the fiducial; and   on determining that the lowest resolution image does not include the image of the fiducial, selecting the target to be of the second target type of the second media size.   
     
     
         16 . A method for determining a size of a target placed on a platen of a scanner having a scan lid with a backer mounted thereon providing a background for the target when the scan lid is in a closed position relative to the platen during a scanning operation, the method comprising:
 providing a first fiducial on the background between a first location corresponding to an edge of a first target type of a first media size and a second location corresponding to an edge of a second target type of a second media size greater than the first media size;   providing a second fiducial on the background between the second location and a third location corresponding to an edge of a third target type of a third media size of a third media size greater than the second media size;   placing the target on the platen;   when the scan lid is in the closed position, scanning the target and the backer to create a scanned image;   determining whether or not the scanned image includes at least one of an image of the first fiducial and an image of the second fiducial; and   on determining that the scanned image does not include respective images of the first and second fiducials, selecting the target to be of the third target type of the third media size.   
     
     
         17 . The method of  claim 16 , further comprising on determining that the scanned image includes the image of the first fiducial, selecting the target to be of the first target type of the first media size. 
     
     
         18 . The method of  claim 16 , further comprising on determining that the scanned image does not include the image of the first fiducial but includes the image of the second fiducial, selecting the target to be of the second target type of the second media size. 
     
     
         19 . The method of  claim 16 , wherein the determining includes searching the scanned image for the images of the first and second fiducials in a direction from the first location to the third location. 
     
     
         20 . The method of  claim 16 , wherein the determining includes searching the scanned image for the images of the first and second fiducials using fast template matching.