AN2676 Freescale Semiconductor / Motorola, AN2676 Datasheet - Page 9

• Manufacturer Part Number: AN2676
• Description: Image Capture with i.MX21
• Manufacturer: Freescale Semiconductor / Motorola

Sensors with Bayer, YUV444, or RGB888 output are also supported, with several software blocks inserted
in between.
Path 1 (Red)—A smart sensor with YUV422 and RGB565 output is used. A full-sized image is converted
to YUV420 by PRP channel 2 for compression by a software JPEG encoder. The same image is resized
and converted to RGB565 by PRP channel 1 for preview.
Path 2 (Blue)—A dumb sensor with Bayer output and a smart sensor with YUV444 / RGB888 output fall
into this category. Data is passed to a software routine for color processing and color conversion to
generate RGB565 output, and this is fed back to the PRP, via a frame buffer, for resizing and further color
conversion. A full-sized image is converted to YUV420 by PRP channel 2 for compression by a software
JPEG encoder. The same image is resized and converted to RGB565 by PRP channel 1 for preview.
7.3 Video Record
Video captured by the sensor is encoded into MPEG4 format. This can be stored in mass storage devices,
or streamed out by network for video exchange (conferencing). View finding on a local LCD screen is
supported.
The image is captured in full or sub-sampled resolution in either YUV422 or RGB565 format. The output
from PRP channel 1 is in RGB565 format, a sub-sampled version for display. The output from PRP
channel 2 is in YUV420 format in full size for MPEG4 encoding. Both outputs are placed in memory.
Sensors with Bayer / YUV444 / RGB888 output are also supported, with several software blocks inserted
between.
MOTOROLA
CSI
Camera
Control
STAT FIFO
Buffer
Line
YUV422
RGB565
Freescale Semiconductor, Inc.
YUV444
RGB888
For More Information On This Product,
Bayer
MC9328MX21 Application Note
Frame
Buffer
Color
PRP
Proc
Go to: www.freescale.com
Figure 7. Still Capture
RGB565
RGB565
YUV420
Frame
Buffer
Frame
Buffer
JPEG
SLCDC
Enc
LCDC
Storage
Memory
MX21 Module
Software
Image Data Path
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