MULTI-CORE PROCESSOR FOR PORTABLE DEVICE WITH IMAGE SENSOR AND MULTI-POINT FOCUS IMAGE CAPTURE
A multi-core processor is used in a portable device with image sensor with adjustable focal length for sensing a scene. The multi-core processor has multiple processing units incorporated onto a single chip and an image sensor interface on the chip. The image sensor interface is configured to provide the processing units with image data from the image sensor, and the processing units are configured to divide the image data into selected regions of the scene and simultaneously derive an image sharpness metric for each of the regions. This metric is used to determine an optimal focal length for each of the selected regions when the image sharpness metric for that region of the scene is above a threshold. Using this data, the portable device captures an image of the scene at each of the optimal focal lengths.
1 . A multi-core processor for a portable device with image sensor with adjustable focal length for sensing a scene, the multi-core processor comprising:
multiple processing units incorporated onto a single chip;
an image sensor interface on the chip; wherein,
the image sensor interface is configured to provide the processing units with image data from the image sensor, and the processing units are configured to divide the image data into selected regions of the scene and simultaneously derive an image sharpness metric for each of the regions, to determine an optimal focal length for each of the selected regions when the image sharpness metric for that region of the scene is above a threshold, such that the portable device captures an image of the scene at each of the optimal focal lengths.
2 . The multi-core processor according to claim 1 wherein the processing units divide the scene into three regions arranged horizontally adjacent one another.
3 . The multi-core processor according to claim 1 further configured to detect faces using hue and local feature analysis.
4 . The multi-core processor according to claim 1 further comprising a display interface on the chip wherein the portable device has a color display for viewing an image captured by the image sensor and the display interface is configured to transmitting processed data from the processing units to the color display.
5 . The multi-core processor according to claim 4 wherein each of the processing units have at least one address generator for the processed data.
6 . The multi-core processor according to claim 5 wherein each of the processing units has RAM (random access memory) for microcode written to the RAM for operative control of that processing unit.
7 . The multi-core processor according to claim 6 further comprising a central processing unit for providing a processing core to write microcode to the RAM in each of the processing units.
8 . The portable device according to claim 7 further comprising a keyboard interface for user input of instructions to the central processor unit such that the central processor rewrites the microcode in the RAM within each of the processing units.
9 . The multi-core processor according to claim 8 further comprises a crossbar switch for interconnecting each of the processing units.
10 . The multi-core processor according to claim 9 comprising four of the processing units wherein the multi-core processor further comprises an input FIFO (first in, first out) and an output FIFO, the input FIFO being configured for receiving data from the first and second image sensor interfaces and inputting the data to the four processing units, and the output FIFO being configured for receiving the processed data to be read by other components.
11 . The multi-core processor according to claim 10 further comprising a data bus connecting the central processing unit to the input FIFO and the output FIFO.
12 . The multi-core processor according to claim 11 further comprising a data cache to store the processed data until required by the central processing unit.
13 . The multi-core processor according to claim 12 wherein the portable device has an inkjet printhead and the multi-core processor being configured to perform one or more processing tasks selected from:
rotating the data from the image sensor interface for printing by the printhead;
colour converting the data from the image sensor interface for printing by the printhead; and,
dithering the data from the image sensor interface for printing by the printhead.
14 . The multi-core processor according to claim 13 further comprising a scanner interface on the chip wherein the portable device has a scanner for scanning encoded data printed on a substrate in a machine readable form, the scanner interface being configured for receiving image processing data from the scanner and inputting the image processing data to the processing units.
15 . The multi-core processor according to claim 14 wherein the scanner interface is connected to the input FIFO and the four processing units operate in accordance with image processing instructions in the encoded data scanned by the scanner.
16 . The multi-core processor according to claim 15 further comprising an authentication chip interface wherein the portable device has a print media roll holding a roll of media substrate on which the printhead prints, the print media roll being removable and replaceable, and the authentication chip interface is configured for interrogating an authentication chip in the media roll for authentication information.
17 . The multi-core processor according to claim 16 further comprising a USB interface wherein the portable device has a USB port for communication with an external device for inputting processing instructions to the central processor unit.
18 . The multi-core processor according to claim 1 wherein the processing units are configured to operate using a 1.5V power supply.