Real Time Image Warper using Digilent Spartan 3 FPGA

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Real Time Image Warper using Digilent Spartan 3
FPGA

• By Shane Agnew
• Supervisor Dr. Fearghal Morgan
• Final Year Project

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Contents

• Initial aims / Specifications
• Introduction
• Camera
• Bitmaps
• VHDL
• Graphical User Interface
• Future Work
• Summary

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Initial aims / Specifications

• Generate image data
• Incorporate a communication protocol into the
  design
• Perform all required file formatting
• Implement digital
• signal processing
• on-board the FPGA
• Develop a real-time
• multi-functional
• video processing
• application

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Introduction
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Camera

• Trust 120 Spacecam
• Standard web camera
• 24-bit BMP Output
• Software provided
• 24-bit BMPs
• Simple to use
• Uncompressed data
• Most web-cameras support them
• 1 byte for each of red, green and blue, hence RGB
  value

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Bitmaps

• 8-bit BMPs
• Limited SRAM memory available
• 3 times less communication overhead
• 3 times less file access
• Less awkward to process and store in SRAM
• Single byte represents a single pixel

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Bitmaps Greyscale

• Greyscale
• 256 colours available
• Black represents 0, white represented by 255
• 24-bit BMP converted to 8-bit by processing each
  pixels RGB value

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Bitmaps Colours

• Colours
• 256 Colours created using RGB values from 0 0
  0 to 100 100 100, e.g. 20 red 0 green 20
  blue
• 24-bit pixels rounded to these boundaries
• Colours sorted by hue to give a natural colour
  progression

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VHDL AppliedVHDLUSBSimple System Overview
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VHDL DPIMREF
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VHDL DPIMREF

• Sample provided by Digilent
• Provides VHDL side USB interface with USB 2.0
  Peripheral Device
• Altered to generate rxDatValid and txDatAck
  signals
• These signals along with the rxDat and txDat
  input and output data lines allow communication
  with rest of the appliedVHDLUSBSimple system

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VHDL IOCtrlr
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VHDL IOCtrlr

• Responds to USB transfer signals, rxdatValid and
  txDatAck, generated by the DPIMREF
• Allows the system registers (CSRs) to be setup,
  both DSP and Input/Output
• Keeps track of the total number of bytes written
  or read from SRAM and increments the current SRAM
  address accordingly
• Controls DSP activation

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VHDL DSPBlk
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VHDL DSPBlk

• Six DSP functions implemented
• Delta function
• Colour inversion
• Flip image over y-axis
• Distortion
• Morphing
• Colour change
• Effective demonstrations of the Spartan 3s power
  but more complex DSP functions are possible

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Graphical User Interface
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Graphical User Interface

• Allows a user to check the contents of any SRAM
  location
• Can activate the camera software to take pictures
• Image loading and conversion from 24-bit to 8-bit
  BMPs
• DSP options as mentioned previously
• Option to perform all operations in colour or
  greyscale

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Future Work

• Implement more complicated DSP, including
• Edge detection
• Object Extraction
• Object warping
• Provide networking solution to allow Electronics
  department to host the project and make it
  accessible anywhere in the world

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Summary

• Initial aims / Specifications
• Introduction
• Camera
• Bitmaps
• VHDL
• Graphical User Interface
• Future Work
• Summary