Dual mode digital camera for video and still operation

#This invention is generally related to electronic imaging and more particularly to digital cameras.

#The digital camera has recently been developed as a portable system that acquires and stores digital still images in electronic form. The images may be used in a number of different ways, such as being displayed in an "electronic" photo album or used to embellish graphical computer applications. The digital camera has a user interface much like a conventional chemical film camera, but the images are captured and stored entirely using electronic solid state circuitry and image processing techniques.

#A typical digital camera has an electronic image sensor that receives incident light reflected from an object or scene through an optical interface. The optical interface may include a lens system, an aperture mechanism, and perhaps a light filter. The sensor can typically be implemented as an array of charge coupled device (CCD) or complimentary metal oxide semiconductor (CMOS) photodetecting circuits that create light-generated signals in response to the incident light. Analog signals from the sensor are converted into digital format by an analog-to-digital (A/D) converter and are then further processed by logic circuitry and/or a programmed processor to yield a captured digital image of the object or scene. The image may then be stored in local memory aboard the camera. In addition, the image may be transferred to a computer that is linked to the digital camera, for storage as an electronic file and/or for further graphical and image processing to improve the image quality or use with graphics software.

#These and other features as well as advantages of the different embodiments of the invention will be apparent by referring to the drawings, detailed description and claims below, where:

#FIG. 1 is a logical block diagram of a digital image capture apparatus according to an embodiment of the invention.

#FIG. 2 illustrates an architecture for a signal and image processing system according to another embodiment of the invention.

#As briefly summarized above, the invention is directed at a method of signal processing in a system and apparatus that operates in at least two modes to provide still and video images through the same signal processing system, thereby reducing the cost to the consumer of purchasing separate still image and video cameras. In one embodiment, the signal processing system provides video and still data from the same detailed, original image sensor signals by performing digital image processing operations in a chain fashion. The original image sensor signals are digitized and prepared to be spatially scaled, and then decorrelated and encoded into compressed data. The different image processing operations are implemented in reprogrammable logic circuitry accessible through a computer bus, or alternatively by programming a high performance data processor to execute the operations in software.

#For purposes of explanation, specific embodiments are set forth below to provide a thorough understanding of the invention. However, as understood by one skilled in the art, from reading this disclosure, the invention may be practiced without such details. Furthermore, well-known elements, devices, process steps, and the like, are not set forth in detail in order to avoid obscuring the invention.

#FIG. 1 is a logical block diagram of a digital image capture apparatus 100 such as a digital camera having a video and still processing block 110 according to an embodiment of the invention. The apparatus 100 includes an optical interface having a lens system 104 and an aperture 108 for being exposed to incident light reflected from an object 102 whose image is to be captured. The apparatus 100 may also include a strobe or electronic flash for generating supplemental light to further illuminate the object 102 when the apparatus 100 is operating under low light conditions.