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January 27, 2014 Sam Siewert

Computer and Machine

Vision

Lecture Week 3

Part-1

Outline of Week 3

Processing Images and Moving Pictures –

High Level View and Computer

Architecture for it

Linux Platforms for Computer/Machine

Vision

I/O, Memory and Processing Challenges

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Old School Moving Picture Media

and Cameras NTSC OTA (1941, 1953 color, 2009 dead)

– Analog, Interlaced, Continuous Broadcast Transmission or CCTV (Closed Circuit TV)

– Coax Cable or Tuner with Immediate CRT Display

– No Buffers, No Routing, No De-mux

– No Compression

Analog Cable

AM/FM OTA

Film Projectors

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Modern Digital Cameras Camera Link – High Frame Rates

– High Data Rates and Resolutions

– Industry Standard for Machine Vision Automation

– E.g. Inspection Systems

– E.g. – Sony, IDT, National Instruments

SD-SDI and HD-SDI – Standard and High Definition Synchronous Digital Interface

– Standard for Studios, Broadcast

Digital Cinema – Red Camera

– 1080p, 2K, 4K Resolutions and Much Higher

– Automated Digital Delivery and Projection

Webcams and Mobile Phone Cameras – Very Low Cost

– Proprietary

– Performance Varies Dramatically

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Differences Analog vs Digital Encoding for Transmission

– Digital Allows for Image Processing

– Adds Latency

– Requires Compression for Packet Switched Networks and Storage

Routed (Diversely), Buffered

Compressed (MPEG, JPEG) to Lower Bit-rates

Multiplexed (Shares Transmission Carrier for Audio, Video, Channels)

Transported by IP (Large Packets)

Continuous Transmission – Analog or Constant Bit-Rate / Frame-Rate

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E.g. UAV Latency and Jitter

Verification of Video Frame Latency Telemetry for UAV Systems Using A Secondary Optical Method, Sam Siewert, Muhammad Ahmad, Kevin Yao

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NTSC (Analog TV)

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AM Video to CRT

FM Audio

Chroma Added Later

Odd/Even Lines (Interlaced)

29.97 FPS (30 before color)

Vertical Blanking (CRT Retrace Time, Closed Captioning)

525 Lines, 262.5 per Field, 60 Fields per Second

http://en.wikipedia.org/wiki/File:Ntsc_channel.svg

Linux in Computer Vision

Embedded Solutions – Texas Instruments OMAP (Beagle xM, Bone)

– Numerous ARM SoCs (NVIDIA, Qualcomm, Broadcomm, …)

Scalable Solutions – Multi-Core (Xeon Phi)

– Vector Processing – CUDA, OpenCL GPU and GP-GPU

Computer and Machine Vision is I/O, Memory and Processing Intensive

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Camera Interfaces

CCD (Charge Coupled Device) or CMOS (Common Metal Oxide Substrate) Detector – Integration Time for Photo-sensitive Elements in Array (to Build

up Charge)

– Read-out Time to Sample Elements in Array

Luminance and Chroma Analog to Digital Conversion

Double Buffer for Read-out + Processing

Frame Capture – http://www.cse.uaa.alaska.edu/~ssiewert/a485_doc/Frame-

Capture-Chips/

– Host Interface over PCI Bus or USB

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Digital Video Transport QoS Latency – To Tune in a Program, Turn-on

– To Deliver a Video Frame or Audio PCM Sample

– To Start, FF, REW, Start-Over, Pause

Bandwidth – Resolution, Lossy/Lossless Compression, High Motion

– Pixel Encoding for Color

– Frame Rate

– Constant Bit-rate Transport?

– Variable Bit-rate Transport and Encoding?

Jitter – Decode and Presentation Rates

– Elasticity in Decode to Presentation Buffering Necessary

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January 27, 2014 Sam Siewert

Linux System Options

(Linux for Image Processing, Camera

Interfacing and Computer Vision)

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Processing Outline

Many-Core Linux Host(s)

– Intel Atom

– ARM

– Xeon

GP-GPU Vector Processing PCI-E Co-Processors

NVIDIA Tesla/Fermi

AMD ATI

NPTL – Native POSIX Threads Library

NPTL Example Code Walkthrough

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Conceptual View of RT Resources Three-Space View of Utilization Requirements

– CPU Margin?

– IO Latency (and Bandwidth) Margin?

– Memory Capacity (and Latency) Margin?

Upper Right Front Corner – Low-Margin

Origin – High-Margin

Mobile – Must Consider Battery Life Too (Power)

CPU-Utility

IO-Utility

Memory-Utility

Processing – Initial Focus Processing and Scaling Frame Transformation, Encode, Decode is Critical

Memory for Buffering (Frame Transformations, CPU Integrated or GPU Offloaded – e.g. Linux VDPAU)

I/O for Networking (Transport)

I/O for Storage (On-Demand, Post, Non-Linear Editing)

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Flynn’s Computer Architecture

Taxonomy Single Instruction Multiple Instruction

Single Data SISD (Traditional Uni-

processor)

MISD (Voting schemes

and active-active

controllers)

Multiple Data SIMD (e.g. SSE 4.2, GP-

GPU, Vector Processing)

MIMD (Distributed

systems (MPMD),

Clusters with MPI/PVM

(SPMD), AMP/SMP)

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GPC has gone MIMD with SIMD Instruction Sets and SIMD Offload

(GP-GPU) NUMA vs. UMA (Trend away from UMA to NUMA or MCH vs. IOH)

SMP with One OS (Shared Memory, CPU-balanced Interrupt Handling,

Process Load Balancing, Mutli-User, Multi-Application, CPU Affinity

Possible)

MIMD - Single Program Multi-Data vs. Multi-Program Multi-Data

Computer and Machine Vision

Treated as a Real-time and/or Interactive

System

– Requires Predictable Response (By Deadline)

– Rate Monotonic

– Earliest Deadline First

– Least Laxity First

Covered in Depth in OS and Digital Media

(Just be Aware for Computer Vision) Sam Siewert 16

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CPU Scheduling Taxonomy Execution Scheduling

Global-MP Local-Uniprocessor

Distributed Asymmetric

(AMP )

Symmetric

(SMP OS)

Preemptive Non-Preemptive

Fixed-Priority

Hybrid

Dynamic-Priority Cooperative

Batch

FCFS SJN

Co-Routine Continuation

Function

Heuristic EDF/LLF RR Timeslice

(desktop)

Multi-Frequency

Executives

Static Dynamic

Rate

Monotonic

Deadline

Monotonic

Dataflow

(Preemptive, Non-Preemptive Subtree

Under Each Global-MP Leaf)

SMT

(Micro-Paralell)

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Response Latency Ci WCET

Input/Output Latency

Interference Time

Event

Sensed Interrupt Dispatch Preemption Dispatch

Interference

Completion

(IO Queued)

Actuation

(IO Completion)

Input-Latency

Dispatch-Latency

Execution Execution

Output-Latency

Time

Response Time = TimeActuation – TimeSensed

(From Release to Response)

Resource Scaling

Processing – Co-Processors – GPU – CUDA, OpenCL

– Many-Core – E.g. Intel Xeon Phi MICA

– FPGA – E.g. Altera Stratix

– Ideally Camera Interface

I/O – High Rate Transport – HD-SDI, Camera Link, GigE/10GE

Memory – SSD, PCIe Nand, NVM – FusionIO, Micron, Intel

– Memristor (Future)

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