Patent Publication Number: US-2005122405-A1

Title: Digital cameras and methods using GPS/time-based and/or location data to provide scene selection, and dynamic illumination and exposure adjustment

Description:
TECHNICAL FIELD  
      The present invention relates generally to digital cameras and methods.  
     BACKGROUND  
      When using digital cameras, there are a finite number of illumination sources that are used. These are generally very common ones such as indoor lighting using fluorescent lights or a flash devices, for example, and daytime lighting, twilight lighting, and nighttime lighting, for example.  
      Because of the atmosphere, the actual color of daylight changes across the globe. For example, daylight at the equator is not the same in terms of color spectrum as daylight in Canada, for example. Current solution creates a single illumination profile for all the illumination sources stored in the camera and applies all of them regardless of geographic location. It would be desirable to improve upon this limiting conventional technique.  
      In addition, it would be desirable to have a digital camera that has menu selections that allow a user to predetermine the type of scene that is to be photographed. This would allow parameters for photographing the scene to be more accurately determined. There are two known conventional solutions that provide this.  
      The first is that the camera simply does its best based on a number of parameters and tries to determine the scene. However, this technique is error prone. The second is that a user preselects the scene that is to be shot. This is much more accurate, but requires additional steps in the setup of the picture that is to be taken, which also adds complexity to the user interface of the camera.  
      However, the way that the camera currently determines a scene type is much more a process of elimination than it is a process of determination. For example, available scene types are “ruled out” until one scene type remains, which therefore “must be” the correct scene type, or several scene types are left and a guess is made as to which one it should be, but only after all extraneous scene types have been ruled out.  
     SUMMARY OF THE INVENTION  
      The present invention comprises digital cameras and methods that employ location and time data to automatically select and/or adjust prestored profiles, such as scene parameters and illumination source profiles (exposure and color balance, for example) used when taking photographs at different geographic locations. One aspect of the present invention provides for the use of GPS data, or localization data entered into a digital camera by a user, to generate a better representation of illumination that should be used when taking photographs with the digital camera at a particular location. This aspect of the present invention uses one instantiation of GPS integration with a digital camera.  
      This aspect of the present invention involves selection of geographic location by a user where a photograph is to be taken using a menu system that is displayed on the camera. Based on that geographic location, one of a number of standard illumination sources stored in the camera is changed to have a more optimal illumination source profile using a different mathematical representation of the standard illumination source based upon the particular geographic location. This aspect of the present invention creates a better illumination source profile based on the specific geographic location where the picture is being taken.  
      Another aspect of the present invention minimizes or eliminates the need for the user to manually predetermine parameters for optimizing the photograph of a particular scene using the camera. The digital camera comprises prestored parameters for different scene types (scene profiles). By knowing the geographic location (either using GPS coordinates or manually entered coordinates or a location) and the time that the photograph is taken (again using GPS time or a manually entered time) firmware running on the camera can determine preferred parameters for the scene that is to be photographed.  
      Using the location and time information, the firmware eliminates those of the stored scene types (scene profiles) that are not appropriate for the location and/or time. The firmware then determines or selects an optimal scene profile and scene parameters from the remaining scene types or profiles that configure the digital camera. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The various features and advantages of embodiments of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:  
       FIGS. 1   a  and  1   b  are rear and front views, respectively, of an exemplary digital camera that may be used in a system in accordance with the principles of the present invention; and  
       FIG. 2  illustrates an exemplary method in accordance with the principles of the present invention. 
    
    
     DETAILED DESCRIPTION  
      Referring to the drawing figures,  FIGS. 1   a  and  1   b  are rear and front views, respectively, of an exemplary digital camera  10  implemented in accordance with the principles of the present invention. As is shown in  FIGS. 1   a  and  1   b , the exemplary digital camera  10  comprises a handgrip section  20  and a body section  30 . The handgrip section  20  includes a power button  21  or switch  21  having a lock latch  22 , a record button  23 , a strap connection  24 , and a battery compartment  26  for housing batteries  27 . The batteries may be inserted into the battery compartment  26  through an opening adjacent a bottom surface  47  of the digital camera  10 .  
      As is shown in  FIG. 1   a , a rear surface  31  of the body section  30  comprises a liquid crystal display (LCD)  32  or viewfinder  32 , a rear microphone  33 , a joystick pad  34 , a zoom control dial  35 , a plurality of buttons  36  for setting functions of the camera  10  and a video output port  37  for downloading images to a computer, for example. The display  32 , joystick pad  34 , and buttons  36  comprises a user interface  18  of the digital camera  10 .  
      As is shown in  FIG. 1   b , a zoom lens  41  extends from a front surface  42  of the digital camera  10 . A metering element  43  and front microphone  44  are disposed on the front surface  42  of the digital camera  10 . A pop-up flash unit  45  is disposed adjacent a top surface  46  of the digital camera  10 .  
      An image sensor  11  is coupled to processing circuitry  12  (illustrated using dashed lines) that are housed within the body section  30 , for example. An exemplary embodiment of the processing circuitry  12  comprises a microcontroller (μC)  12  or central processing unit (CPU)  12 . The processing circuitry  12  (μC  12  or CPU  12  is coupled to a nonvolatile (NV) storage device  14 , and a high speed (volatile) storage device  15 , such as synchronous dynamic random access memory (SDRAM)  15 , for example. The processing circuitry  12  is also coupled to a GPS (global positioning system) receiver (GPS RCVR)  16  that receives position data (position coordinates) and time data from orbiting GPS satellites. The user interface  18  also allows manual entry of position and time data.  
      The digital camera  10  comprises prestored parameters for different scene profiles or scene types and illumination source profiles. The scene profiles define different predetermined exposure and scene type or profile settings for the camera  10 , for example. Typical scene profiles include portrait, macro, and sports mode, for example. The illumination source profiles (exposure and color balance, for example) define different predetermined lighting effects that may be selectively applied to a recorded photograph.  
      The processing circuitry  12  (microcontroller (μC)  12  or CPU  12 ) in the digital camera  10 , embodies firmware  13  comprising a software algorithm  13  in accordance with the principles of the present invention. The firmware  13  in conjunction with the GPS receiver  16  and user interface  18  implement the novel aspects of the present invention.  
      The firmware  13  is operative to automatically select and adjust scene parameters and illumination source profiles, based upon the specific geographic location and time that the photograph is to be taken.  
      One aspect of the firmware  13  generates an optimal representation of illumination that should be used when taking a photograph at a particular location based upon geographic location and time. For example, the geographic location is entered into the camera  10  by way of the GPS receiver  18  or manually by the user using a menu system of the user interface  18 . Based on that geographic location, one of the prestored standard illumination sources is changed to a more optimal illumination source profile using a different or calculated mathematical representation of the standard illumination source. This aspect of the present invention creates a better illumination source profile based on the specific geographic location where the photograph is being taken.  
      This first aspect of the present invention thus provides for the use of GPS or localization data entered into a digital camera  10  by a user, to generate a better representation of illumination that should be used when taking photographs with the digital camera at a particular location. An advantage provided by the first aspect of the present invention is that better image quality through more accurate representations of the illumination sources based on geographic location.  
      Another aspect of the firmware  13  minimizes or eliminates manual user parameter determination for optimizing the photograph of a particular scene. As was mentioned above, the digital camera  10  comprises prestored parameters for different scene types (scene profiles). The geographic location and the time that the photograph is taken, using GPS coordinates and time or manually entered coordinates or time, the firmware  13  determine preferred parameters for the scene that is to be photographed.  
      Thus, by knowing the geographic location (either using GPS coordinates or manually entered coordinates or a location) and the time that the photograph is taken (again using GPS time or a manually entered time) firmware running on the camera can determine preferred parameters for the scene that is to be photographed. Using the location and time information, the firmware  13  eliminates those stored scene types (scene profiles) that are not appropriate for the location and/or time. The firmware  13  then determines or selects an optimal scene profile and scene parameters from the remaining scene types or profiles and configures the digital camera  10 .  
      By way of example, every camera manufacturer has their own concept of what the illumination source and scene profiles look like. More precisely, each camera manufacturer has an algorithm by which they use the expected illumination source to impact how they modify the colors that come off of the image sensor  11 . What is possible using the present invention, however, is to have a “global profile” (that tries to minimize errors across all possible type of color that could be in a picture), and then modify this. By way of example, if one is in the Caribbean, the water is known to have an aqua-green color. Rather than minimize the error, the global profile may be changes to “maximize” the representation of aqua-green colors (water). This type of “color balancing” (minimizing error across all color representations) is well-known in the art.  
      An advantage provided by this second aspect of the present invention is that the selected scene profile is more accurate than in cameras that do not allow the user to input scene selection criteria. Also, this aspect simplifies or removes the portion of the user interface for cameras that allow the user to select the scene type prior to pressing the shutter and taking the photograph.  
       FIG. 2  illustrates an exemplary method  60  in accordance with the principles of the present invention. The exemplary method  60  comprises the following steps.  
      A digital camera  10  is provided  61  that comprises a user interface  18  and processing circuitry  12 . The processing circuitry is configured  62  to run firmware  13 . A plurality of scene profiles are stored  63  in the camera. The profiles may be a plurality of scene profiles and/or a plurality of illumination source profiles. The user interface is used to enter  64  position data (position coordinates) and time data into the camera. Position and time data may be entered  64  using a GPS receiver  16  or may be manually entered  64 . The firmware  13  is configured  65  to select one or more profiles, such as a scene profile (parameters) and/or an illumination source profile based upon the geographic location and time data that were entered, typically the time and location that the photograph is to be taken.  
      Thus, digital cameras and methods have been disclosed that employ location and time data to automatically select and adjust scene parameters and illumination source profiles used when taking photographs at different geographic locations. It is to be understood that the above-described embodiments are merely illustrative of some of the many specific embodiments that represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.