Patent Publication Number: US-2007109415-A1

Title: Methods and systems for anti-vibration verification for digital image acquisition apparatuses

Description:
BACKGROUND  
      The present invention relates to apparatus verification, and more particularly, to methods and systems for anti-vibration verification for digital image acquisition apparatuses.  
      Digital image acquisition apparatuses such as digital cameras, digital video recorders or similar, are typically equipped with anti-vibration systems to prevent blurring of the acquired images. Various solutions such as mechanism compensation, software compensation or similar, are introduced to reduce the vibration caused by shaking of the apparatus. In these anti-vibration systems, however, effectiveness of the anti-vibration feature is difficult to verify.  
     SUMMARY  
      Methods for anti-vibration verification in digital image acquisition apparatuses are provided. An embodiment of a method for anti-vibration verification in a digital image acquisition apparatus comprises the following steps. An animation is shown on a display, simulating that images captured by the digital image acquisition apparatus is vibrating during recording. A video stream comprising multiple images is acquired where the video stream is acquired by recording the animation with the digital image acquisition apparatus to create the animation. It is determined whether an anti-vibration function of the digital image acquisition apparatus is adequate by sequentially detecting the difference between the images in the video stream.  
      The animation may initially display an object at a default location on the display, and the object is repeatedly moved for a distance in a direction after a time period and is moved back to the default location after the same time period. The color of the object may be a contrast color of the background color in the animation. The number of times the object moves per second may be less than the number of images recorded in the video stream per second. The digital image acquisition apparatus may capture the animation in a stationary status.  
      The determining step may further comprise the following steps. Locations of the objects in the images are acquired until the entire video stream is completely processed. It is determined whether the difference between the acquired locations in any two adjacent images is less than a predetermined threshold. A difference number representing the number of the images exceeding the predetermined threshold is updated when the difference between the acquired locations exceeds the predetermined threshold. It is determined whether the difference number is less than a tolerance threshold after the entire video stream is completely processed. It is determined that the performance of the anti-vibration function of the digital image acquisition apparatus is adequate when the difference number is less than a tolerance threshold. The tolerance threshold may be equal to number of the images multiplied by a percentage. It is determined that the performance of the anti-vibration function of the digital image acquisition apparatus is inadequate when the difference number is not less than a tolerance threshold. The anti-vibrating extent of the anti-vibration function may be determined contingent upon the moving distance.  
      A machine-readable storage medium storing a computer program which, when executed by a computer, performs the anti-vibration verification method for a digital image acquisition apparatus is also provided.  
      Systems for anti-vibration verification in digital image acquisition apparatuses are provided. An embodiment of a system comprises a display, a digital image acquisition apparatus and a processing unit. The display plays an animation simulating images captured by digital image acquisition apparatuses vibrating during recording. The digital image acquisition apparatus captures the animation to generate a video stream comprising multiple images. The processing unit determines whether the performance of the anti-vibration function of the digital image acquisition apparatus is adequate by sequentially detecting the difference between the images in the video stream.  
      The processing unit may repeatedly acquire locations of the object in two adjacent images among the images until the entire video stream is completely processed, determine whether the difference between the acquired locations is less than a predetermined threshold, update a difference number representing number of images exceeding the predetermined threshold when the difference between the acquired locations exceeds the predetermined threshold, determine whether the difference number is less than a tolerance threshold after the entire video stream is completely processed, determine that the performance of the anti-vibration function of the digital image acquisition apparatus is adequate when the difference number is less than a tolerance threshold, and determine that the performance of the anti-vibration function of the digital image acquisition apparatus is inadequate when the difference number is not less than a tolerance threshold. The success of the anti-vibrating effect of the anti-vibration function may be determined contingent upon the moving distance. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      The invention will become more fully understood by referring to the following detailed description with reference to the accompanying drawings, wherein:  
       FIG. 1  is a diagram of the system architecture of an embodiment of an anti-vibration verification system;  
       FIG. 2  is a diagram of a hardware environment applicable to an embodiment of a digital image acquisition apparatus;  
       FIG. 3  is a diagram of a hardware environment applicable to an embodiment of a computer;  
       FIG. 4  is a schematic diagram of an embodiment of an animation;  
       FIG. 5  is a flowchart of an embodiment of a method for playing an animation;  
       FIG. 6  is a flowchart illustrating an embodiment of a method for image inspection;  
       FIG. 7  is a diagram of a storage medium storing a computer program for anti-vibration verification in digital image acquisition apparatuses. 
    
    
     DETAILED DESCRIPTION  
       FIG. 1  is a diagram of the system architecture of an embodiment of an anti-vibration verification system  10  comprising computers  13  and  15 , and a digital image acquisition apparatus  11  such as a digital camera, digital video recorder or similar. The computer  13  displays a series of images to simulate. The digital image acquisition apparatus  11  records the series of images displayed by the computer  13  in a video file comprising a series of still pictures. The computer  15  loads the video file recorded by the computer  13  and analyzes the difference between pictures therein to determine the ability of the anti-vibration functions provided by the digital image acquisition apparatus  11 . Those skilled in the art will realize that the computers  13  and  15  could be integrated in a single computer.  
       FIG. 2  is a diagram of a hardware environment applicable to an embodiment of the digital image acquisition apparatus  11  comprising lens  21 , an image sensor chip  23 , a front end signal processor  25 , an image processor  27  and a storage device  29 . Moreover, those skilled in the art will understand that some embodiments may be practiced with other portable electronic devices, including personal digital assistants (PDAs), mobile phones or similar. The digital image acquisition apparatus  11  records color images as intensities of red, green and blue light, which are stored as variable charges on the image sensor chip  23  such as a complementary metal-oxide semiconductor (CMOS) or a charge-coupled device (CCD) image sensor chip. The charges, which are actually analog, are converted to digital signals by the front end signal processor  25  for storage in the storage device  29  such as flash memory, optical disks, hard disks, or similar. The image processor  27  records the converted digital signals to video streams containing a series of still pictures in a relevant format such as MPEG, audio video interleaved (AVI) or similar.  
       FIG. 3  is a diagram of a hardware environment applicable to an embodiment of computers  13  and  15 , comprising a processing unit  31 , memory  32 , a storage device  33 , an output device  34 , an input device  35  and a communication device  36 . The processing unit  31  is connected by buses  37  to the memory  32 , storage device  33 , output device  34 , input device  35  and communication device  36  based on Von Neumann architecture. There may be one or more processing units  31 , such that the processor of the computer comprises a single central processing unit (CPU), a microprocessing unit (MPU) or multiple processing units, commonly referred to as a parallel processing environment. The memory  32  is preferably a random access memory (RAM), but may also include read-only memory (ROM) or flash ROM. The memory  32  preferably stores program modules executed by the processing unit  31  to perform anti-vibration verification functions. Generally, program modules include routines, programs, objects, components, or others, that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will understand that some embodiments may be practiced with other computer system configurations, including handheld devices, multiprocessor-based, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. Some embodiments may also be practiced in distributed computing environments where tasks are performed by remote processing devices linked through a communication network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices based on various remote access architectures such as DCOM, CORBA, Web objects, Web Services or similar. The storage device  33  may be a hard drive, magnetic drive, optical drive, portable drive, or nonvolatile memory drive. The drives and associated computer-readable media thereof (if required) provide nonvolatile storage of computer-readable instructions, data structures, program modules and/or video files.  
      The computer  13  plays an animation on a display such as cathode ray tube (CRT) display, liquid crystal display (LCD), plasma display, organic light-emitting diode display (OLED) or similar, through the output device  34 . The animation simulates images captured by a digital image acquisition apparatus vibrating during recording.  FIG. 4  is a schematic diagram of an embodiment of an animation comprising a series of sequential images  41  to  49  respectively containing a display object Obj. In general, the display object Obj moves a predetermined distance in a direction after a predetermined time period and moves back to the original position after the same time period. Preferably, the moving distance Xt of the object Obj between two instances is a constant value to facilitate the determination of the anti-vibration extent of the digital image acquisition apparatus  11 . The number of times the object Obj moves per second is preferably less than the number of images recorded in the video stream per second. For example, when the number of the images recorded in the video stream is thirty per second, the number of times the object Obj moves may be ten, fifteen, twenty or twenty-five per second. The object Obj may be a geometric pattern such as a circle, rectangle, triangle or similar, filled with a particular color preferably a contrast color of the background color, for example, black against white, red against green, blue against yellow or similar.  
       FIG. 5  is a flowchart of an embodiment of a method for playing an animation, performed by the processing unit  31  of the computer  13 . In step S 51   1 , an object Obj is displayed at a default position. In step S 53   1 , a period of time elapses. In step S 533 , the object Obj is moved by a predetermined distance. In this step, the object Obj is moved in an arbitrary direction such as up, down, left, right, upper-left, upper-right, lower-left, lower-right or similar. In step S 541 , a period of time elapses. In step S 543 , the object Obj is moved back to the default position.  
      The digital image acquisition apparatus  11  is fixed on a tripod and captures an animation shown on a display as a stationary status, in which the animation simulates images captured by the digital image acquisition apparatus  11  vibrating during recording. A video stream containing recorded images is stored in a video file and the video file is transmitted to the computer  15  by a physical wire connection such as IEEE 1394, universal serial bus (USB), recommended standard-232 (RS-232) or similar, over a network such as a local area network (LAN), wireless LAN, Internet, or from a portable storage medium such as an optical disk, portable drive, hard drive, memory card or similar, for subsequent analysis. When the performance of the anti-vibration function of the digital image acquisition apparatus  11  is adequate, the object Obj in each recorded image is located at a default position or located at a location near the default position.  
      The computer  15  acquires a video stream in a video file and determines the performance of the anti-vibration function of the digital image acquisition apparatus  11  by sequentially detecting the difference of locations of the objects Objs between adjacent images.  FIG. 6  is a flowchart illustrating an embodiment of a method for image inspection, performed by the processing unit  31  of the computer  15 . In step S 611 , a video stream is acquired from a video file. In step S 621 , the first and second images are retrieved from the acquired video file as first and second comparison images. In step S 631 , it is determined whether the difference of locations of the object Obj displayed in the first and second comparison images is less than a predetermined threshold. If so, the process proceeds to step S 641 , otherwise, to step S 633 . In step S 633 , a difference number representing the number of images exceeding the predetermined threshold is increased by one. In step S 641 , it is determined whether all recorded images are completely analyzed. If so, the process proceeds to step S 651 , otherwise, to step S 643 . In step S 643 , the second comparison image is set as the first comparison image. In step S 645 , the next image is retrieved from the video stream as the second comparison image. In step S 651 , it is determined whether the difference number is less than a tolerance threshold. If so, the process proceeds to step S 653 , otherwise, to step S 655 . The tolerance threshold may be a fixed constant or be calculated according to the number of images of the acquired video stream, for example, the tolerance threshold denotes five percent of the number of images. In step S 653 , it is determined that the performance of the anti-vibration function of the digital image acquisition apparatus  11  is adequate. In step S 655 , it is determined that the performance of the anti-vibration function of the digital image acquisition apparatus  11  is inadequate. Note that the success of the anti-vibrating effect of the anti-vibration function is determined contingent upon the predetermined distance as shown in step S 533  ( FIG. 5 ).  
      Also disclosed is a storage medium as shown in  FIG. 7  storing a computer program  720  providing the disclosed methods for anti-vibration verification of digital image acquisition apparatuses. The computer program includes a storage medium  70  having computer readable program code therein for use in a computer system. The computer readable program code comprises at least an animation computer readable program code  721  playing an animation simulating images captured by a digital image acquisition apparatus vibrating during recording (as shown in  FIG. 5 ), and an inspection computer readable program code  722  inspecting images (as shown in  FIG. 6 ).  
      Systems and methods for anti-vibration verification for digital image acquisition apparatuses, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMS, hard drives, nonvolatile memory devices, or any other machine-readable storage medium, wherein, when the program code is loaded into and executed by a machine, such as portable apparatuses and the like, the machine becomes an apparatus for practicing the invention. The disclosed methods and systems may also be embodied in the form of program code transmitted over some transmission medium, such as electrical wiring or cabling, through fiber optics, or via any other form of transmission, wherein, when the program code is received and loaded into and executed by a computer, the machine becomes an apparatus for practicing the invention.  
      Certain terms are used throughout the description and claims to refer to particular system components. As one skilled in the art will appreciate, consumer electronic equipment manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function.  
      While the invention has been described in terms of preferred embodiment, it is not intended to limit the invention to the precise embodiments disclosed herein. Those who are skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the invention shall be defined and protected by the following claims and their equivalents.