Image processing apparatus

• US 6,141,435 A
• Filed: 07/23/1996
• Issued: 10/31/2000
• Est. Priority Date: 03/31/1993
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Shiohara, Morito, Naoi, Satoshi, Egawa, Hiroichi
• Primary Examiner(s): CHANG, JON CARLTON
• Application Number:
  US08/681,485
• Time in Patent Office: 1,561 Days
• Field of Search: 382/100, 382/104, 382/190, 382/279, 382/282, 382/107, 348/135, 348/143, 348/148, 348/149, 348/169-172, 701/114, 340/936, 340/937
• US Class Current: 382/104
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning

Abstract

An image processing apparatus for extracting the specified objects has a background image extract unit for extracting a background; a first average background extract unit which extracts an image that includes a plurality of stationary and moving objects each having a speed not higher than a predetermined first speed and also the background; a second average background extract unit which extracts an image that includes the stationary and moving objects each having a speed not higher than a predetermined second speed and also the background; a first difference-calculation processing unit which calculates a difference between an output from the background image extract unit and an output from the first average background extract unit as a first speed image; a second difference-calculation processing unit which calculates a difference value between two outputs from the first and second average background extract units as a second speed image; and a third difference-calculation processing unit which calculates a difference value between an original image and either one of outputs from the first and second average background extract units as a third speed image.

Claims

1. An image processing apparatus for extracting objects, in a case where a plurality of stationary objects and a plurality of moving objects are in a series of images which are captured at different sampling times, the objects being classified into plural speed ranges, said apparatus comprising:

an image-input unit which inputs each of said images and each including a background and a plurality of said stationary and moving objects;

a background image extract unit which extracts said background from each of said images and stores said background;

a first average background extract unit which extracts an image that includes one or a plurality of said stationary objects or moving objects each having a first object speed not higher than a predetermined first speed and also includes said background;

a second average background extract unit which extracts an image that includes one or a plurality of said stationary objects or moving objects each having a second object speed not higher than a predetermined second speed and also includes said background;

a first difference-calculation processing unit which calculates a difference value between an output from said background image extract unit and said first average background extract unit, and then generates a first image which classifies the objects into stationary objects and objects moving at said first object speed;

a second difference-calculation processing unit which calculates a difference value between respective outputs from said first and second average background extract units, and then generates a second image which classifies the objects into objects moving at said second object speed classified as a second one of said plural sorts of speed; and

a third difference-calculation processing unit which calculates a difference value between an output from said image-input unit and either one of outputs from said first and second average background extract unit, and then generates a third image which classifies the objects into objects moving at a third speed.

2. An image processing apparatus as set forth in claim 1, wherein said apparatus further comprises a plurality of local-area characteristic-amount extract processing units which process outputs from said image-input unit, each of said plurality of local-area characteristic-amount extract processing units including:

a local-area determining unit which allocates said outputs from said image-input unit to each of a plurality of local areas;

a labeling processing unit which identifies at least one object in each of said local areas, by labeling a same object existing in each of said plurality of local areas; and

a characteristic-amount calculating unit which calculates a plurality of characteristic-amounts for the labeled object in said plurality of local areas.

3. An image processing apparatus as set forth in claim 1,

wherein said apparatus is operative to calculate a difference between said background and an average background image, and to extract one or a plurality of connected areas of connected objects from a difference image obtained by the thus calculated difference,

wherein said apparatus is operative to produce an object projection for each of said connected areas, and to calculate a position of the corresponding object in accordance with said projection, and to calculate a plurality of characteristic-amounts, which at least include a value of a length and breadth of said object or the value of an area of said object,

wherein said apparatus is operative to estimate a change in position of said object and also a change in said characteristic-amounts of said object for each of the sampling times in a time series, and

wherein said apparatus is operative to identify said object as a stationary object, in a case where both of the change in said position of said object and the change in said characteristic-amounts are small.

4. An image processing apparatus as set forth in claim 2, wherein said apparatus further comprises local-area characteristic-amount extract units corresponding to said local areas, for each of the speed ranges which is output from said difference-calculation processing units.

5. An image processing apparatus as set forth in claim 2, wherein said apparatus comprises a locus calculation unit having a list making unit, which detects an existence of said object in each of said plurality of local areas in a time series, on the basis of an output from each of said plurality of local-area characteristic-amount extract processing units, and which creates a list of results of the detection.

6. An image processing apparatus as set forth in claim 5, wherein said locus calculation unit includes a character analyzing unit for identifying a locus of the same moving object, on the basis of a shape of said moving object.

7. An image processing apparatus as set forth in claim 5, wherein said apparatus is adapted to allocate a plurality of local areas in each image which are to be processed, and to check whether one of said moving objects passes through each of said local areas, and to calculate a locus of the same moving object, in accordance with a shape of said moving object and a time when said moving object passes through each of said local areas, and to discriminate a change in the speed of said moving object and a change in the direction thereof, and to identify said moving object.

8. An image processing apparatus as set forth in claim 5,

wherein said apparatus is adapted to allocate a plurality of areas in each image which are to be processed, in accordance with a size of a plurality of the moving objects, and

wherein said locus calculation unit includes a list analyzing unit for discriminating a locus of each of a plurality of small-scale moving objects in each of said areas, and for identifying a locus of a same moving object, even in a case where a large-scale moving objects obscures said plurality of small-scale moving objects.

9. An image processing apparatus as set forth in claim 6, wherein said apparatus is adapted to allocate a plurality of local areas which are to be processed, and to examine periodically whether said moving object passes through each of said local processed areas, and to examine periodically the shape of said moving object, and to identify at least one flashing object.