Application Programs and Systems - Heterogeneous Multicore Processor Technologies for Embedded Systems - page 205

Fig. 6.32 RP-X application
system diagram

USB
Mouse

USB
Camera

USB Hub

USB Host
Controller

Hard Disk Drive

OS lib Appli.

Off-chip Interconnect

RP-X

Off-chip
Bus
Controller

CPU
#0

CPU
#1

CPU
#2

CPU
#3

SATA
Controller

On-chip Interconnect

DRAM
Controller

LDC
Controller

Video
encoder

Frame
buffer
Plane 0

Display

DRAM

effects. However, the application presented here has been modified to perform the
three visual effects in parallel to take advantage of a multicore processor.
The original SUSAN program accepts an image file stored in the portable gray
map (PGM) format as an input, reads the size of image and subsequent 8-bit gray-
scale images, and distributes the input to one of the visual effect algorithms. In this
implementation, however, the visual images are captured via the USB video class
(UVC) device and stored in the YUY2 format once and then converted into the 8-bit
grayscale format as the input to each visual effect algorithm. The size of the image
is smaller than 320 × 240 pixels and is one of the sizes supported by the USB cam-
era. Figure 6.32 shows the system diagram of the RP-X application.
The software architecture of the RP-X application is shown in Fig. 6.33 . The
SUSAN process creates four threads: “input,” “smoothing,” “edges,” and “corners.”
The “input” thread converts the captured image in the YUY2 format into the 8-bit
grayscale format. The “smoothing” thread smoothes shapes. The “edges” thread
finds edges in the image. The “corners” thread finds corners in the image. The system
is built to take advantage of the X-window system on the Linux operating system.