KR20000016778A - Method and apparatus for generating digital map images of a uniform format - Google Patents

Abstract

PURPOSE: A computer-implemented method is provided for converting printed maps into digitally stored images of a unique format. CONSTITUTION: Bit mapped map images corresponding to a printed map are obtained by scanning or other means. A bit mapped map image is then cropped to select a map image corresponding to a desired geographic area, such as a one degree by one degree area (80). The boundaries of the selected map image are moved to shape the geographic area into a tessellated shape, such as a rectangle. The selected map image is then realized to contain a predetermined pixel area (82). The map image, now of a uniform format, is then stored within an identifier of a reference point and size of the geographic area (84) represented by the map image. For example, the identifier (84) may be the name of a computer-readable file containing the map image.

Description

Method and apparatus for generating digital map images in uniform format

Computer systems capable of generating and displaying geographic map images are currently commonly available. Typically, a computer system that provides a map image has stored data corresponding to the map image in a memory system, such as in secondary storage. Map image data, if stored as a bitmap, can then be retrieved directly for display.

Map image data can also be stored as information in a database and computer systems can independently generate map images from database information.

A popular use of the increasing trend of computer generated map images is for graphical navigation systems, such as "moving map" systems. For example, Pioneer Electronics of Tokyo, Japan, has designed a mobile map system for vehicles such as automobiles. The mobile map system receives data from a global positioning system (GPS) satellite to determine the current position of the vehicle. The moving map system uses this data to select geographic data stored in the system, such as on a CD-ROM, and retrieve a map image of the current location for display therefrom. A map image is a varying combination of images that is created as if the vehicle is actually moving from one geographic location to another, providing a situation in which the map is moving. The cursor on the map image shows the vehicle driver the current vehicle position and allows him to navigate according to the map image.

A drawback of current computer systems for displaying map images is that the quality of map images displayed by the computer system is poor. In systems that generate map images from data inherent in the database, the details of the map images are poor. Only those geographic objects recorded in database fields appear on the image. For example, the map database may include fields for placing objects on the map, but cannot provide fields for displaying topological shapes such as elevation and valleys. On the other hand, systems that store detailed map images as bitmaps do not store images in a uniform format. If no uniform format is used, the bitmapped image changes in size, making it difficult to accurately determine the location of the vehicle on the map image and display it. Variable sizes also allow gaps on the screen when an image of one size is replaced with an image of another size. Various images are pieces of puzzles that are coarsely fitted that cannot be joined without having a gap between them.

Therefore, one object of the present invention is to provide a method for providing a highly detailed map image in a uniform format. This format will allow the computer system to display the cursor (ie, the point of interest) on the map image to accurately show the geographic location of the vehicle. This format will also allow the map images to seamlessly match each other so that no gaps appear on the display when one image is replaced by another. When used in a moving map system, the map image will provide an aspect of the uniform image as the vehicle moves from one geographic region to another geographic region across individual map images. It is another object of the present invention to provide an apparatus in which a map image in uniform format is stored into a computer system for easy retrieval.

These and other objects of the present invention will become more apparent from the following detailed description of preferred embodiments.

Summary of the Invention

In accordance with the present invention, a computer-implemented method of generating a digital map image in uniform format is shown and described. In such a method, a bitmapped map image corresponding to the printed map is provided. The bitmapped map image is then cropped to select the map image corresponding to the desired geographic region, such as 1 degree x 1 degree square. The boundary of the selected map image is selectively moved to form the geographic area into a checkerboard shape such as a rectangle. The selected map image is then rearranged to include predetermined pixel regions. The map image currently configured in a uniform format is then stored with the identifier of the reference point, such as the size of the geographic area represented by the map image, and the location. For example, the identifier can be the name of a computer readable file containing the map image.

The starting bitmapped map image may be obtained from the printed map through scanning or other known technique to convert the printed graphic into an electronic image. Preferred geographic regions can be defined on the map by reference grid lines such as latitude and longitude lines.

The apparatus according to the present invention may comprise a storage medium such as a CD-ROM in which a plurality of bitmapped geographic map images are stored in computer readable form. Each image has an identifier of a reference point and size of the geographic region represented by the map image and a predetermined pixel region. The identifier is preferably the name of an image file.

CD-ROMs and other devices stored in accordance with the method of the present invention provide a storage of unique map images that can be used in a number of ways. Map images are particularly useful in moving map systems where it is desirable to visualize detailed graphical information on the display, such as a car, airplane, or other vehicle moving from one geographic location to another. Another useful use is to construct a customer map and print it. For example, multiple map images can be retrieved from a CD-ROM and combined into a larger map containing the planned travel route. The layer map image is then printed.

These and other advantages and features of the present invention will become apparent from the following description of the preferred embodiment which follows.

The present invention generally relates to image processing. More specifically, the present invention relates to a method of transforming a printed map into an image of a uniform format stored digitally.

1 illustrates a computer system for converting a printed map into a bitmapped map image in accordance with the present invention.

FIG. 2 shows how a printed map is physically cut, split and edited using the method according to the invention.

3 is a flowchart of the main steps of the method according to the invention.

4 is a flowchart for the conversion step of FIG. 3.

5 is a flow chart for the formatting step of FIG.

6 is a flow chart for the storage step of FIG.

FIG. 7 shows how the map image comes from two printed maps in accordance with the present invention.

1 shows a computer 12, a scanner 14 and a CD recordable device 16 for storing data on a CD-ROM. As will be described in detail below, the printed map is scanned by the scanner 14, which converts the printed map into a digital electronic map image. A printed map is a map that is physically drawn on paper or other media in a form that can be recognized by a human, unlike a map image that appears on a computer display screen or resides in computer memory. This map image is then edited into a unique uniform format using software running on the computer 14. Using device 16, the edited image is then stored on a CD-ROM (read only memory) in one directory, allowing the image to be easily retrieved when the CD-ROM is read from the CD-ROM drive. .

The device described above consists of a conventional design. The scanner 14 may be in the form of a scanning device capable of converting a printed map into an electronic image that may be stored in a computer readable file on a medium such as a disk or tape. In a preferred embodiment, a drum scanner is used because of its large scanning surface. Computer 12 may be a personal computer, workstation or other device capable of editing graphical images included in electronic files. In a preferred embodiment, computer 12 is a personal computer including a hard disk and a tape drive. Such computers are equipped to run image editing software, such as the Adobe Photoshop ^™ computer program, which is incorporated herein by reference and available from Adobe System Incorporated, Mountain View, California. Device 16 is a CD readable device capable of recording data on a CD-ROM. A preferred form of such a device is a JVC model XR-W2001 CD-writable drive with suitable software (Personal Archiver or ROM Marker) for writing once to a recordable compact disc. In a preferred embodiment, the device 16 is also equipped with a hard disk drive to read the map image and store the image data on a CD-ROM. The preferred embodiment uses a tape for moving the map image from the scanner 14 to the computer 12 and a network for moving the image from the computer 12 to the CD-ROM device 16. It should be understood that data can also be moved between these devices in other ways. For example, map image data can be moved by transferring it by wire, disk, or other known method of transferring data between devices.

2A-2D extensively illustrate the steps of the method according to the invention for converting a printed map into a digital map image in uniform format. The main steps are described in the flowchart of FIG. 3, and more detailed steps, including the main steps, are described in FIGS. 4-6.

Referring now to FIG. 3, a first step of the invention is converting a printed map into a bitmapped map image that can be edited with a computer or equivalent device (40). As is known in the art, a bitmapped image is a raster image, where each pixel is represented by one or more bits, such as 8 bits / pixel. Using a computer, the map image is then edited into a uniform format (42). Finally, the edited map images are stored on the CD-ROM in a manner that allows them to be quickly retrieved by a computer or equivalent device (44).

4 shows details of the conversion step 40. A substantial size printed map must first be cut or otherwise divided 46 into a suitable cross section on the scanner 14. As an example, FIG. 2A shows a printed map of the United States. Maps printed to suit the scanner are generally cut along reference lines, such as latitude and longitude lines that appear on several maps. 2B shows a cut cross section with latitude line 47 and longitude line 49. Other reference lines may include alphanumeric lines that often appear on the Citimap. Preferably, the cut section is as large as possible to minimize the effort required to scan the entire map after cutting.

The cut section is then scanned to convert it into a digital image (48). Any scanner that can scan graphical images will work as well. However, in a preferred embodiment, a drum scanner is used because it can scan larger map cross sections. Alternatively, other devices capable of converting printed maps into digital images may be used, such as digital video cameras that capture images for storage in digital form.

The digital map image is then stored on the tape as a universal identifier of the same content as the name of the map and map portion (50).

5 illustrates the detailed steps including editing the digital map image into an image in uniform format. Bitmapped image files from scanners or other sources are loaded into computer 12 for editing using image editing software (60). 2B shows an example of such a map image. Using image editing software, the bitmapped map image is cropped to select a map image that corresponds to a desired geographic region, such as a latitude of 1 degree by a latitude of 1 degree. This site is preferably the site from which all map images of the selected map shape are to be cut. 2C illustrates the cropped image.

Since the latitude line 47 is curved upward in the cut map image and the longitude line 49 is tapered inward, the area between the reference line (longitude and latitude line in the map of FIGS. 2A-D) is rectangular. Please note that no. This rounded shape presents two problems. First, the actual size of the 1 degree x 1 degree map image changes. Images with coordinates near the equator are larger than those near the poles. This makes it difficult to locate a point on the map image because the pixel relationship between the image and the map location is different for each map. For example, if one map image is 600 pixels in diameter and the other image is 400 pixels in diameter, for the reference line, the 200th pixel represents a different map position in each map image. Second, the shapes of the map images are not regular shapes that match each other to provide seamless aspects such as rectangles, triangles, and the like. This form of regular shape is often referred to as a checkerboard shape. Irregular shapes cannot be made into electronically seamless pieces once they are divided and stored as bitmaps. To overcome these difficulties, images are edited using image editing software. However, before initiating the editing process, the image may need to be rotated for proper orientation (64, 66), which may be necessary because of the incorrect orientation of the bitmapped map image when the bitmapped map image was originally scanned. .

Once the image is properly oriented, it is edited in a uniform format using image editing software (68). For example, in an Adobe Photoshop ^™ program, images can be manipulated with skew and distortion functions in particular. However, depending on the size of the cropped image, it can be divided into quadrants that are preferentially edited more easily. Again, this dividing process can be carried out using a cutting tool.

To form the image square along the latitude and longitude lines (or other reference grid lines) of the desired geographic region, the bitman map image is cropped to include these lines. Currently, the edges of the cut image boundary have a “handle” that can be selectively moved to form a geographic area into a rectangular shape using an editing tool. For example, to straighten the curved latitude line 47, one end of such a line is selected and moved until the line is straightened. Likewise, one end of the longitude 49 line can be moved so that the line is perpendicular to the straightened latitude line 47. If necessary, the selected map image containing the current rectangular geographic region is further cropped to match the image region with the geographic region. This cutting step may be necessary if the first cutting process involves more than a geographic site. This manipulation is then performed on the adjacent image quadrants and such images are recombined into images of the desired uniform format.

The selected map image is then rearranged to include predetermined pixel regions (70). Image size commands can be used to accomplish this step. A preferred pixel portion is a rectangle that is 720 pixels wide and 900 pixels high.

If the color mode of the edited image is CMYK, the mode can be changed from CMYK to PGB so that the map image can be displayed on the computer display device (72). CMYK (ie, Cyan, Magenta, Yellow and Black) are navy blues used to print color images. As these color inks are applied to each other on one page, they absorb more and more of the light spectrum, and the combination of the four colors gives a black color. On the other hand, RGB (Red, Green, Blue) are additive colors. The additive colors combine to produce white light. Additive colors are used to illuminate video, film recorders and display monitors. Since these map images appear to be primarily visible on the display screen, it is desirable to change the color mode from CMYK to RGB. This change is of course only necessary if the map image does not start in RGB mode.

Often the map image should not be sufficiently focused to be sharp to increase its clarity. If necessary, this can be done with a sharpening tool in the image editing software to increase the contrast between the pixels of the image (74).

The final stage of the format process is to convert similar colors of all selected map images into colors of a color palette common to all images (76). By using the same color palette, all maps have the same color for features of the same type. Thus, “moves” across several map images appear to be missing. In this embodiment, the common color palette is the default palette.

Once the image editing process is complete, the image is saved for future reference. 6 shows the steps involved in storing an image. Reference points of pixel regions, such as intersections of longitude and latitude of western and northern map boundaries, are determined (80). This reference point may be an indicator of geographic location. The geographic area of the map image is also determined as 1 degree x 1 degree (82). Thus, the map image is stored with the size of the geographic area and the identifier of the reference point (84). In a preferred embodiment, the identifier is the name of a computer readable file containing an image such as W121-46. W represents the size of the geographic site and the number is a reference point. Of course, it can be any string that can ultimately be used to identify a geographic region of the map, such as an index to a look up table. Of course, other naming conventions can be used so long as they reflect the reference points for the image and the geographic area represented by the image. The location inherent in the map image can be determined precisely from this information, since all map images have the same pixel region. This is a simple process of converting geographic locations into pixel coordinates.

This process is repeated to convert one or more printed maps into a plurality of digital map images. In a preferred embodiment, the edited map image is stored in network storage along with the file directory. From there, the image is transferred to the hard disk drive associated with the CD-ROM device 16. Device 16 reads the image and file directories from the drive and writes them onto the compact disc. The result is a disc containing multiple map images in a uniform format, all of which are stored so that they can be retrieved individually and accurately for display or printing.

In some situations, additional editing is required if the desired map image appears partially on the individually printed map. For example, a 1 degree square cross section may overlap a map on both sides as illustrated in FIG. 7. Each of these partial sections is initially scanned as a bitmapped map image. Portions of the preferred map image are then cut away from the bitmapped map image. The two cut portions are then merged into a single map image which is edited in the manner described above.

While the principles of the invention have been illustrated and described in the preferred embodiments so far, it will be apparent to those skilled in the art that the embodiments can be arranged and modified in detail without departing from such principles. For example, reference points other than latitude and longitude locations may be used. In some situations, a bitmapped map image can already be utilized without scanning, in which case the method of the present invention begins to provide a bitmapped map image.

In view of the various possible embodiments to which the principles of the invention may be applied, it should be appreciated that the above illustrated embodiments are merely preferred examples of the invention and should not be taken as a limitation on the scope of the invention. Rather, the invention is defined by the appended claims. Therefore, the inventors claim as the present invention all such embodiments that fall within the scope and spirit of these claims.

Claims (18)

In a computer implemented method for converting a printed map into a digital map image, Converting the printed map into a bitmapped map image corresponding to the printed map; Truncating the bitmapped map image to select a map image corresponding to a desired geographic region; Moving a boundary of the selected map image to form the geographic area into a checkerboard shape; Arranging the selected map image to include a predetermined pixel portion; And Storing the selected map image with the size of the geographic region represented by the selected map image and the identifier of the reference point Computer implemented method comprising a. 2. The method of claim 1, comprising repeating the steps of forming a plurality of digital map images from the printed map, each image having a size of a geographic area and an identifier of a reference point and a uniformity of a predetermined pixel area. A computer implemented method of formatting. The computer implemented method of claim 1 wherein the identifier is a name of a computer readable file containing the map image. The computer-implemented method of claim 1, wherein the storing comprises storing the selected map image on a CD-ROM. The computer-implemented method of claim 1, wherein the desired geographic region is defined by a reference gridline and the selected map image is cut into a defining gridline. The computer implemented method of claim 1 wherein the reference grid lines are latitude and longitude lines. The computer-implemented method of claim 1, wherein the size of the geographic region is 1 degree × 1 degree. 2. The computer-implemented method of claim 1, wherein the selected map image carries a desired geographic region, further comprising truncating the selected map image as needed to align the image region with a checkerboard geographic region. The computer implemented method of claim 1 wherein the step of converting comprises electronically scanning the printed map using a scanner to produce a digital bitmapped image. 2. The computer-implemented method of claim 1, wherein the truncating step includes truncating the selected image into smaller images that are moved, arranged, and merged into the selected image for storage. 2. The method of claim 1, further comprising repeating the steps of forming a plurality of digital map images from the printed map and converting the colors in each selected map image to colors in a color palette common to all selected map images. Computer-implemented method. An apparatus for providing a plurality of digital map images, A storage medium for a computer system for storing bitmapped geographic map images in a computer readable form; And A plurality of bitmapped geographic map images stored in a computer readable file on the medium, wherein the size of the same checkered geographic region represented by the map image and the identifier of the reference point and the predetermined pixel region Multiple bitmapped geographic map images with Device comprising a. 13. The apparatus of claim 12, wherein the storage medium is a CD-ROM. 13. The apparatus of claim 12, wherein the identifier is a name of a computer readable file containing the map image. In a computer implemented method for generating a digital map image in a uniform format, Providing a bitmapped map image corresponding to the printed map; Truncating the bitmapped map image to select a map image corresponding to the desired geographic region; Moving the boundaries of the selected map image to form said geographic region in a checkerboard shape; Arranging the selected map image to include a predetermined pixel portion; And Storing the selected map image with the size of the geographic region represented by the selected map image and the identifier of the reference point Computer implemented method comprising a. 16. The computer-implemented method of claim 15, wherein the desired geographic area is defined by a reference gridline, further comprising truncating the selected map image with the reference gridlines. 17. The method of claim 16 wherein the reference gridlines are longitude and latitude lines. 17. The computer implemented method of claim 16 wherein the checkerboard shape is rectangular.