Method and apparatus for determining the status of frame data transmission from an imaging device
View Patent ↗A method and apparatus for determining the status of frame data transmission from an imaging device. According to one aspect of the invention, a graphics controller interfaces with a host and an imaging device, preferably a camera. A count value is specified, preferably by the host. Frame data received from the imaging device are counted to determine an actual count. A comparison is made between the actual count and the count value. Preferably, responsive to the comparison, an indication signal is generated for interrupting the host.
1. In a graphics controller for interfacing with a host and an imaging device, a method for detecting when a resolution of frames of image data transmitted from the imaging device changes, the method comprising:
receiving a first frame of image data;
subsequently receiving a second frame of image data;
counting frame data of the first frame to produce a first count to determine the size of the first frame;
counting frame data of the second frame to produce a second count to determine the size of the second frame, wherein, if the determined size of the second frame is substantially different than the determined size of the first frame, the method further comprises generating a first indication signal; and
performing an operation external to the graphics controller in timed relation to the generation of said first indication signal; and
wherein said external operation includes generating a flash for illuminating a subject for imaging by the imaging device.
2. The method of claim 1 , further comprising generating said first indication signal only if the determined size of the second frame is substantially larger than the determined size of the first frame.
3. The method of claim 1 , further comprising receiving a third frame of image data subsequent to receiving the second frame and counting frame data of the third frame to determine the size of the third frame, and if the determined size of the third frame is substantially the same as the determined size of the second frame, generating a second indication signal.
4. The method of claim 1 , further comprising receiving a third frame of image data subsequent to receiving the second frame and performing an image processing operation in the graphics controller on the frame data of said third frame.
5. The method of claim 4 , wherein said image processing operation includes one of (a) compression encoding and (b) compression decoding said frame data of said third frame.
6. The method of claim 3 , further comprising generating a flash in timed relation to the generation of said second indication signal for illuminating a subject for imaging by the imaging device.
7. The method of claim 1 , further comprising causing a host interrupt request to be generated in response to said first indication signal.
8. In a graphics controller for interfacing with a host and an imaging device, a frame detector for detecting when a resolution of frames of image data transmitted from the imaging device changes, comprising:
a counter;
a controller to cause said counter to count frame data of a received, first frame to produce a first count, and to determine the size of the first frame from said first count, to cause said counter to count frame data of a received, second frame to produce a second count, and to determine the size of the second frame from said second count, and if the determined size of the second frame is substantially different than the determined size of the first frame to generate an indication signal; and
a unit to generate a flash in timed relation to the generation of said indication signal, said flash for illuminating a subject.
9. The frame detector of claim 8 , further comprising means for causing a host interrupt request to be generated in response to said indication signal, wherein the host, in response to said interrupt request, directs the graphics controller to perform an image processing operation on frame data.