Camera system dual-encoder architecture

• US 9,420,173 B2
• Filed: 02/20/2016
• Issued: 08/16/2016
• Est. Priority Date: 10/01/2013
• Status: Active Grant

• Current Assignee: GoPro, Inc.
• Original Assignee: GoPro, Inc.
• Inventors: Campbell, Scott Patrick, Mobbs, Paul, Adsumilli, Balineedu Chowdary, Chawla, Sumit
• Primary Examiner(s): LAM, HUNG H
• Application Number:
  US15/049,013
• Publication Number:
  US 20160173776A1
• Time in Patent Office: 178 Days
• Field of Search: 348/218.1, 348/222.1, 348/294, 348/333.02
• US Class Current: 1/1
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns
• CPC Class Codes: H04N 1/6019 using look-up tables H04N1/6025 takes precedence
• CPC Class Codes: H04N 1/6027 Correction or control of colour gradation or colour contrast H04N1/6058 takes precedence
• CPC Class Codes: H04N 19/102 characterised by the element, parameter or selection affected or controlled by the adaptive coding
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/156 Availability of hardware or computational resources, e.g. encoding based on power-saving criteria
• CPC Class Codes: H04N 19/164 Feedback from the receiver or from the transmission channel
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/1883 the unit relating to sub-band structure, e.g. hierarchical level, directional tree, e.g. low-high [LH], high-low [HL], high-high [HH]
• CPC Class Codes: H04N 19/33 in the spatial domain
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/517 by encoding
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
• CPC Class Codes: H04N 23/13 with multiple sensors
• CPC Class Codes: H04N 23/60 : Control of cameras or camera modules
• CPC Class Codes: H04N 23/62 : Control of parameters via user interfaces
• CPC Class Codes: H04N 23/64 : Computer-aided capture of images, e.g. transfer from script file into camera, check of taken image quality, advice or proposal for image composition or decision on when to take image
• CPC Class Codes: H04N 23/667 : Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 23/6811 : based on the image signal
• CPC Class Codes: H04N 23/683 : performed by a processor, e.g. controlling the readout of an image memory
• CPC Class Codes: H04N 23/69 : Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming
• CPC Class Codes: H04N 23/73 : by influencing the exposure time
• CPC Class Codes: H04N 23/80 : Camera processing pipelines; Components thereof
• CPC Class Codes: H04N 23/843 : Demosaicing, e.g. interpolating colour pixel values
• CPC Class Codes: H04N 23/88 : for colour balance, e.g. white-balance circuits or colour temperature control
• CPC Class Codes: H04N 23/90 : Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums
• CPC Class Codes: H04N 25/75 : Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/76 : Addressed sensors, e.g. MOS or CMOS sensors
• CPC Class Codes: H04N 9/8042 : involving data reduction

Abstract

An image capture accelerator performs accelerated processing of image data. In one embodiment, the image capture accelerator includes accelerator circuitry including a pre-processing engine and a compression engine. The pre-processing engine is configured to perform accelerated processing on received image data, and the compression engine is configured to compress processed image data received from the pre-processing engine. In one embodiment, the image capture accelerator further includes a demultiplexer configured to receive image data captured by an image sensor array implemented within, for example, an image sensor chip. The demultiplexer may output the received image data to an image signal processor when the image data is captured by the image sensor array in a standard capture mode, and may output the received image data to the accelerator circuitry when the image data is captured by the image sensor array in an accelerated capture mode.

Claims

1. A camera system, comprising:

an image sensor chip configured to produce image data representative of light incident upon the image sensor chip;

an image signal processor chip (“

ISP”

) configured to process the image data; and

an image capture accelerator chip (“

ICA”

) coupled between the image sensor chip and the ISP, the image capture accelerator comprising;

an input configured to receive the image data from the image sensor chip;

a decimator configured to decimate the received image data into a plurality of image sub-band components;

a wavelet encoder configured to encode a first subset of the plurality of image sub-band components;

an H.264 encoder configured to encode a second subset of the plurality of image sub-band components;

a concatenator configured to concatenate the encoded first subset of image sub-band components and the second subset of image sub-band components to produce concatenated encoded image sub-band components; and

an output configured to output the received image data when the ICA is configured to operate in a normal mode and to output the concatenated encoded image sub-band components when the ICA is configured to operate in an accelerated mode.

2. The camera system of claim 1, wherein the wavelet encoder comprises an entropy encoder.

3. The camera system of claim 1, wherein the first subset of image sub-band components comprises a high/low sub-band component, a low/high sub-band component, and a high/high sub-band component.

4. The camera system of claim 1, wherein the second subset of image sub-band components comprises a low/low sub-band component.

5. The camera system of claim 1, wherein the output is configured to output the received image data to the ISP when the ICA is configured to operate in the normal mode.

6. The camera system of claim 1, wherein the output is configured to output the concatenated encoded image sub-band components to a memory for storage when the ICA is configured to operate in an accelerated mode.

7. The camera system of claim 6, wherein the ICA further comprises:

one or more decoders configured to access the stored concatenated encoded image sub-band components from the memory, split the concatenated encoded image sub-band components into the encoded first subset of image sub-band components and the second subset of image sub-band components, and decode the encoded first subset of image sub-band components and the second subset of image sub-band components to produce the plurality of image sub-band components;

wherein the output is further configured to output the plurality of image sub-band components to the ISP after the one or more decoders produce the plurality of image sub-band components.

8. A method for capturing images by a camera system, comprising:

capturing, by an image sensor chip, light incident upon the image sensor to produce image data representative of the captured light;

decimating, by an image capture accelerator chip (“

ICA”

) coupled to the image sensor chip, the received image data into a plurality of image sub-band components;

encoding, by a wavelet encoder of the ICA, a first subset of the plurality of image sub-band components;

encoding, by an H.264 encoder of the ICA, a second subset of the plurality of image sub-band components;

concatenating the encoding first subset of image sub-band components and the second subset of image sub-band components to produce concatenated encoded image sub-band components;

when the ICA is configured to operate in a normal mode, outputting the received image data; and

when the ICA is configured to operate in an accelerated mode, outputting the concatenated encoded image sub-band components.

9. The method of claim 8, wherein the wavelet encoder comprises an entropy encoder.

10. The method of claim 8, wherein the first subset of image sub-band components comprises a high/low sub-band component, a low/high sub-band component, and a high/high sub-band component.

11. The method of claim 8, wherein the second subset of image sub-band components comprises a low/low sub-band component.

12. The method of claim 8, wherein outputting the received image data comprises outputting the received image data to an image signal processing chip (“

ISP”

) coupled to the ICA.

13. The method of claim 8, wherein outputting the concatenated encoded image sub-band components comprises outputting the concatenated encoded image sub-band components to a memory for storage.

14. The method of claim 13, further comprising:

accessing the stored concatenated encoded image sub-band components from the memory;

splitting the concatenated encoded image sub-band components into the encoded first subset of image sub-band components and the second subset of image sub-band components;

decoding the encoded first subset of image sub-band components and the second subset of image sub-band components to produce the plurality of image sub-band components; and

outputting the plurality of image sub-band components to the ISP decoding the encoded first subset of image sub-band components and the second subset of image sub-band components.

15. An image capture accelerator integrated circuit (“

ICA”

), comprising;

an input configured to receive image data captured by an image sensor chip;

a decimator configured to decimate the received image data into a plurality of image sub-band components;

a wavelet encoder configured to encode a first subset of the plurality of image sub-band components;

an H.264 encoder configured to encode a second subset of the plurality of image sub-band components;

a concatenator configured to concatenate the encoded first subset of image sub-band components and the second subset of image sub-band components to produce concatenated encoded image sub-band components; and

an output configured to output the received image data when the ICA is configured to operate in a normal mode and to output the concatenated encoded image sub-band components when the ICA is configured to operate in an accelerated mode.

16. The ICA of claim 15, wherein the wavelet encoder comprises an entropy encoder.

17. The ICA of claim 15, wherein the first subset of image sub-band components comprises a high/low sub-band component, a low/high sub-band component, and a high/high sub-band component.

18. The ICA of claim 15, wherein the second subset of image sub-band components comprises a low/low sub-band component.

19. The ICA of claim 15, wherein the output is configured to output the received image data to an image signal processor chip (“

ISP”

) when the ICA is configured to operate in the normal mode.

20. The ICA of claim 15, wherein the output is configured to output the concatenated encoded image sub-band components to a memory for storage when the ICA is configured to operate in an accelerated mode, and further comprising:

one or more decoders configured to access the stored concatenated encoded image sub-band components from the memory, split the concatenated encoded image sub-band components into the encoded first subset of image sub-band components and the second subset of image sub-band components, and decode the encoded first subset of image sub-band components and the second subset of image sub-band components to produce the plurality of image sub-band components;

wherein the output is further configured to output the plurality of image sub-band components to an ISP after the one or more decoders produce the plurality of image sub-band components.