Abstract:
A method that enables correction of photographs obtained by a handheld device without equipping the handheld device with bulky and expensive motion compensation mechanisms or expensive processing resources for supporting correction algorithms. A method for correcting a photograph according to the present teachings includes transferring the photograph from the handheld device to a remote system and then obtaining a corrected photograph from the remote system. The fact that a remote system corrects the photograph obviates the need for expensive mechanisms/resources in the handheld device.

Description:
BACKGROUND  
       [0001]     A variety of handheld devices that may not be traditionally regarded as cameras may be provided with the capability of taking photographs. For example, cell phones, PDAs, handheld digital music players, etc. may include digital cameras.  
         [0002]     Photographs taken with a handheld device may exhibit blurring. For example, a user may inadvertently shake a handheld device while taking a photograph. The shaking motion of A handheld device may cause a number of adjacent pixels on its digital image sensor to sample light from the same area of an image scene, thereby yielding a blurred photograph.  
         [0003]     Prior methods for avoiding blurred photographs include providing a camera with motion compensation mechanisms for adjusting the positions of its optics or its image sensor in response to movement of the camera. Unfortunately, such mechanisms may be too bulky and expensive for handheld devices.  
         [0004]     Blurred pictures may be corrected using computer-based blur correction. Unfortunately, computer-based blur correction may require relatively powerful processing resources, e.g. a fast processor, math processing capability, large capacity memory, etc. that may be prohibitively expensive for a handheld device.  
       SUMMARY OF THE INVENTION  
       [0005]     A method is disclosed that enables correction of photographs obtained by a handheld device without equipping the handheld device with bulky and expensive motion compensation mechanisms or expensive processing resources for supporting correction algorithms. A method for correcting a photograph according to the present teachings includes transferring the photograph from the handheld device to a remote system and then obtaining a corrected photograph from the remote system. The fact that a remote system corrects the photograph obviates the need for expensive mechanisms/resources in the handheld device.  
         [0006]     Other features and advantages of the present invention will be apparent from the detailed description that follows.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The present invention is described with respect to particular exemplary embodiments thereof and reference is accordingly made to the drawings in which:  
         [0008]      FIG. 1  illustrates a method for correcting a photograph obtained by a handheld device according to the present teachings;  
         [0009]      FIG. 2  shows one embodiment of a handheld device according to the present teachings;  
         [0010]      FIG. 3  illustrates the handling of a multimedia message in a remote system according to the present teachings.  
     
    
     DETAILED DESCRIPTION  
       [0011]      FIG. 1  illustrates a method for correcting a photograph  14  obtained by a handheld device  10  according to the present teachings. The present method includes a remote system  12  and the handheld device  10  transfers the photograph  14  to the remote system  12 . The remote system  12  corrects the photograph  14  so that a corrected version of the photograph  14  may be obtained from the remote system  12 .  
         [0012]     The remote system  12  may apply any correction to the photograph  14 . Example corrections that may be applied to the photograph  14  include blur correction, color correction, correction for problems of contrast, color casts, color saturation, dynamic range, scratches, blemishes, etc. The correction performed by the remote system  12  may be performed automatically in software or may include human intervention in combination with software tools.  
         [0013]     In one embodiment, the remote system  12  obtains a set of meta data from the handheld device  10  and corrects the photograph  14  in response to the meta data. For example, the meta data from the handheld device  10  may indicate a movement of the handheld device  10  while it acquired the photograph  14  and the remote system  12  may use the meta data to apply blur correction to the photograph  14 .  
         [0014]     A user of the handheld device  10  may obtain a corrected version of the picture  14  from the remote system  12 . For example, the remote system  12  may transfer a corrected version of the photograph  14  back to the handheld device  10 . Another handheld device may obtain a corrected version of the picture  14  from the remote system  12 . For example, the remote system  12  may forward a corrected version of the photograph  14  to another handheld device. Others may obtain a corrected version of the picture  14  from a picture server. For example the remote system  12  may forward a corrected version of the photograph  14  to a picture server. The remote system  12  may be an implementation of a picture server.  
         [0015]     The handheld device  10  may be any device capable of taking photographs and communicating with the remote system  12 . Examples of the handheld device  10  include camera phones as well as personal digital assistants (PDAs), handheld computers, laptops, digital music players, etc., with integrated digital cameras.  
         [0016]      FIG. 2  shows one embodiment of the handheld device  10 . The handheld device  10  in this embodiment includes a camera lens and image sensor  20 , an image processing chip  22 , a memory  24 , an accelerometer  26 , and a mobile RF circuit  28 . The camera lens and image sensor  20 , the image processing chip  22 , the memory  24 , and the accelerometer  26  may be contained on a camera module in the handheld device  10 , e.g. a camera module in a camera phone.  
         [0017]     The mobile RF circuit  28  enables communication via a network  50 . The mobile RF circuit  28  may be shared for other functions in the in the handheld device  10 , e.g. telephony, web access, downloading games, etc, depending on the implementation of the handheld device  10 . For example, if the network  50  is a GSM network then the mobile RF circuit  28  is adapted to GSM communication and if the network  50  is a CDMA network then the mobile RF circuit  28  is adapted to CDMA communication.  
         [0018]     The accelerometer  26  generates motion data that indicate movement of the handheld device  10 . The accelerometer  26  may include a silicon pendulum structure in combination a piezo-electric structure that generates a sensor signal having a voltage that indicates a magnitude of a g-force on the handheld device  10 . The accelerometer  26  may include circuitry for converting the sensor signal into a motion vector, a digital value, that indicates motion per unit of time.  
         [0019]     The image processing chip  22  obtains a set of image data for the photograph  14  from the image sensor  20  when the handheld device  10  acquires a photograph, e.g. when a user positions the handheld device  10  and presses a shutter control on the handheld device  10 . The image processing chip  22  obtains a set of motion data from the accelerometer  26  substantially contemporaneously with obtaining the image data of the photograph  14  from the image sensor  20 . The closeness in time of sampling the photograph  14  and obtaining motion data yields motion data that may be used to correct blur in the photograph  14  caused by movement, e.g. shaking, of the handheld device  10  while the photograph  14  was acquired. The image processing chip  22  may obtain a series of motion vectors from the accelerometer  26  during acquisition of the photograph  14  and then derive vibration data from the motion vectors.  
         [0020]     The image processing chip  22  generates a multimedia message  30  that includes the image data for the photograph  14  and that further includes a set of motion data  15  that corresponds in time to the acquisition of the photograph  14  as meta data. The mobile RF circuit  28  obtains the multimedia message  30  from the image processing chip  22  and sends it over the network  50 .  
         [0021]     The multimedia message  30  may include a JPEG encoding of the image data for the photograph  14  with the motion data  15  embedded into the JPEG data, e.g. as meta data, a watermark, etc. The multimedia message  30  may be a GPRS packet, a RX1TT packet, etc., depending on the cellular network to which the handheld device  10  is adapted.  
         [0022]      FIG. 3  illustrates the handling of the multimedia message  30  in one embodiment of the remote system  12 . The remote system  12  in this embodiment includes a picture server  40  and an image corrector  42 . The remote system  12  includes the appropriate network communication elements for communicating over the network  50  depending on the implementation of the network  50 .  
         [0023]     The picture server  40  may provide web based access to photographs obtained from the handheld device  10 . For example, the picture server  40  may be part of a service of a camera phone service provider that enables photographs obtained by camera phones to be accessed by friends and family via the Internet using web protocols.  
         [0024]     The picture server  40  obtains the multimedia message  30  from the handheld device  10  via the network  50 . The picture server  40  extracts the photograph  14  and the motion data  15  from the multimedia message  30  and transfers the photograph  14  and the motion data  15  to the image corrector  42 . The image corrector  42  corrects blur in the photograph  14  using the motion data  15 . In an embodiment in which the handheld device  10  does not provide motion data, the image corrector  42  corrects blur in the photograph  14  in response to the image data of the photograph  14 . The image corrector  42  may perform blur correction to the photograph  14  using known techniques.  
         [0025]     The picture server  40  in this embodiment obtains a corrected photograph from the image corrector  42  and transfers the corrected photograph to a handheld device  11  in a multimedia message  32 . For example, the handheld devices  10  and  11  may be camera phones that exchange photographs via a service of a cellular service provider that implements the present methods via the remote system  12 . The picture server  40  may transfer the multimedia message  32  back to the handheld device  10  to provide the corrected photograph to a user of the handheld device  10 . The picture server  40  may store the corrected photograph in a picture file associated with a user of the handheld device  10  and enable web access to the corrected photograph using Internet protocols. For example, the user of the handheld device  10  and friends and family, etc. of the user of the handheld device  10  may access the corrected photograph on the picture server  40  using a web browser.  
         [0026]     The foregoing detailed description of the present invention is provided for the purposes of illustration and is not intended to be exhaustive or to limit the invention to the precise embodiment disclosed. Accordingly, the scope of the present invention is defined by the appended claims.