Map image processing apparatus and method for forming brids-eye view from two-dimensional map image

• US 20030044081A1
• Filed: 07/29/2002
• Published: 03/06/2003
• Est. Priority Date: 08/29/2001
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Uesugi, Hiroshi
• Granted Patent: US 6,900,817 B2
• Time in Patent Office: Days
• US Class Current: 382/276
• CPC Class Codes: G06T 1/60 Memory management
• CPC Class Codes: G06T 17/05 Geographic models

Abstract

A map image processing method and apparatus produces a birds-eye view in real time from a two-dimensional map image. In this method and apparatus, a map image having a wider area than a display area displayed on the display device is drawn and stored. When a scroll display is instructed, a part of the two-dimensional map image is sequentially read, and a display processing operation is sequentially executed. A birds-eye view is obtained by processing the two-dimensional map image. A display processing operation is applied to the birds-eye view. Since the birds-eye view is formed by simply processing the two-dimensional map image, the birds-eye view image can be produced in high speeds and can be scrolled in a smooth display mode.

Claims

1. A map image processing apparatus comprising:

drawing processing means for drawing a two-dimensional map image;

storage means for storing therein the two-dimensional map image drawn by the drawing processing means;

storage/read-out control means for controlling storing and reading operations of the two-dimensional map image in and from the storage means, respectively; and

display processing means for executing a display processing operation capable of displaying a map image on a display means based upon the two-dimensional map image which is read out from the storage means by the storage/read-out control means,

wherein a map image having a wider area than a display area displayed on the display device is drawn by the drawing processing means, and

wherein, when a scroll display is performed, a portion of the two-dimensional map image stored in the storage means is sequentially read, and the display processing operation by the display processing means is sequentially executed so that a scroll display processing operation is realized,

the apparatus further comprising;

image processing means for processing the two-dimensional map image read out from the storage means by the storage/read-out control means to obtain a birds-eye view,

wherein the display processing means executes the display processing operation with respect to the birds-eye view obtained by the image processing means.

2. The map image processing apparatus as in claim 1, further comprising:

mode switching control means for switching a processing mode in the drawing processing means and the processing mode in the display processing means based upon whether a scroll display is instructed,

wherein the mode switching control means executes a normal mode processing operation and a scroll mode processing operation,

wherein, in the normal mode processing operation, when only the birds-eye view display is instructed, the drawing processing means draws the birds-eye view to be stored in the storage means, and the display processing means reads out the birds-eye view stored in the storage means to execute the display processing thereto, and

wherein, in the scroll mode processing operation, when both the birds-eye view display and the scroll display are instructed, the drawing processing means draws a two-dimensional map image to be stored into the storage means, a portion of the two-dimensional map image stored in the storage means is sequentially read out so as to be processed to obtain the birds-eye view by the image processing means, and the display processing means sequentially displays the birds-eye view obtained by the image processing means so that the scroll display of the birds-eye view is realized.

3. The map image processing apparatus as in claim 2, wherein:

the mode switching control means is capable of switching the processing modes based upon whether a high speed scroll display whose scroll speed is higher than a predetermined speed is instructed; and

the mode switching control means executes the normal mode processing operation when only the birds-eye view display is instructed, and the mode switching control means executes the scroll mode processing operation when both the birds-eye view display and the high speed scroll display are instructed.

4. The map image processing apparatus as in claim 1, wherein the image processing means includes:

a read-out area calculating unit for calculating an area within the two-dimensional image, which is required to be processed to obtain the birds-eye view;

a deformation processing unit for reading the two-dimensional map image of the area calculated by the read-out area calculating unit and for executing a deformation processing operation with respect to the read two-dimensional map image; and

a display area cutting unit for cutting out an area which should be displayed as a birds-eye view from the image which is deformation-processed by the deformation processing unit.

5. The map image processing apparatus as in claim 1, wherein:

either the image processing means or the display processing means performs a blending operation with respect to the birds-eye view obtained by the image processing means in order to represent a perspective feeling.

6. The map imaging processing apparatus as in claim 5, wherein:

either the image processing means or the display processing means has a function of synthesizing a layer image having a predetermined color on the birds-eye view image by executing the a blending operation; and

either the image processing means or the display processing means sets α

values indicative of transmittance in a manner that the α

value is relatively decreased in a lower portion of a display screen so as to clearly display the birds-eye view image, whereas the α

value is relatively increased in an upper portion on the display screen in order that a synthesizing ratio of the predetermined color is increased.

7. The map image processing apparatus as in claim 6, wherein:

while an a plane is previously prepared in which the dimensions of the a values are relatively set in response to the upper/lower portions of the screen, the α

blending operation is performed by employing data of the α

plane.

8. The map image processing apparatus as in claim 1, wherein:

the storage means stores therein the two-dimensional map image represented by a color palette method;

the image processing means is arranged in such a manner that the two-dimensional map image read out from the storage means is converted from color palette data into RGB data, and thereafter the RGB data is processed to obtain the birds-eye view; and

the image processing means executes a gradation processing operation before or after the RGB data is processed to obtain the birds-eye view by which such RGB data as to pixels corresponding to a background color within image data are adjusted so that colors are changed in an asymptotic manner from the lower portion of the display screen up to the upper portion thereof.

9. The map image processing apparatus as in claim 1, wherein:

the image processing means approximates a color of a pixel corresponding to a character within the image data to a preselected color under which a character deformation does not become conspicuous, when the scroll display of the birds-eye view is instructed.

10. The map image processing apparatus as in claim 1, wherein the image processing means includes:

a character area extracting unit for extracting a character area from the map image data before being processed to obtain the birds-eye view;

a character arrangement position calculating unit for calculating a position where a character should be arranged within the birds-eye view obtained by processing the map image data based on the processing content of obtaining the birds-eye view; and

a character data synthesizing unit for synthesizing the data of the character area extracted by the character area extracting unit with the character arrangement position calculated by the character arrangement position calculating unit with respect to the birds-eye view which is obtained after the map image data has been processed,

wherein, after the character area is extracted by the character area extracting unit, the image processing means interpolates a pixel corresponding to the character by a predetermined color, and processes the interpolated image data to obtain the birds-eye view.

11. The map image processing apparatus as in claim 10, wherein:

the character area extracting unit grasps the character area based upon the map image data.

12. The map image processing apparatus as in claim 10, wherein:

the character area extracting unit inputs therein information related to the character region obtained when the drawing processing means draws the two-dimensional map image to grasp the character area.

13. The map image processing apparatus as in claim 2, wherein:

when the processing operation in the normal mode and the processing operation in the scroll mode are transferred, the display processing operation a-blends both the birds-eye view image obtained by the processing operation before being transferred, and another birds-eye view image obtained by the processing operation after being transferred, so that the birds-eye view image obtained by the processing operation before being transferred is smoothly transferred to the birds-eye view image obtained by the processing operation after being transferred.

14. A computer program which causes a computer to realize a function as the map image processing apparatus as recited in claim 1.

15. A map image processing method comprising:

drawing a two-dimensional map image;

storing the two-dimensional map image; and

executing a display processing operation capable of displaying a map image based upon the two-dimensional map image,

wherein a map image having a wider area than a display area is drawn, and

wherein, when a scroll display is performed, a portion of the two-dimensional map image is sequentially read, and the display processing operation is sequentially executed so that a scroll display processing operation is realized,

the method being characterized by further comprising processing the two-dimensional map image to obtain the birds-eye view by calculating an area within the two-dimensional image which is required to be processed to obtain the birds-eye view, reading the two-dimensional map image of the area, executing a deformation processing operation with respect to the read two-dimensional map image, and cutting out an area which should be displayed as the birds-eye view from the image which is deformation-processed, and

the method being further characterized in that the display processing operation is executed with respect to the birds-eye view.