IPSR-VIDEO Altera, IPSR-VIDEO Datasheet - Page 113

• Manufacturer Part Number: IPSR-VIDEO
• Description: RENEWAL Of IPS-VIDEO
• Manufacturer: Altera
• Series: IP Suitesr

Specifications of IPSR-VIDEO

• Software Application: IP CORE, SUITES
• Supported Families: Arria GX, Cyclone II, HardCopy II, Stratix II
• Features: Common Avalon Streaming (Avalon-St) Interface And Avalon-St Video Protocol
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na

Chapter 5: Functional Descriptions
Color Space Converter
Color Space Converter
January 2011 Altera Corporation
Input and Output Data Types
Color Space Conversion
The Color Space Converter MegaCore function provides a flexible and efficient means
to convert image data from one color space to another.
A color space is a method for precisely specifying the display of color using a
three-dimensional coordinate system. Different color spaces are best for different
devices, such as R'G'B' (red-green-blue) for computer monitors or Y'CbCr
(luminance-chrominance) for digital television.
Color space conversion is often necessary when transferring data between devices
that use different color space models. For example, to transfer a television image to a
computer monitor, you may need to convert the image from the Y'CbCr color space to
the R'G'B' color space. Conversely, transferring an image from a computer display to a
television may require a transformation from the R'G'B' color space to Y'CbCr.
Different conversions may be required for standard definition television (SDTV) and
high definition television (HDTV). You may also want to convert to or from the Y'IQ
(luminance-color) color model for National Television System Committee (NTSC)
systems or the Y'UV (luminance-bandwidth-chrominance) color model for Phase
Alternation Line (PAL) systems.
The Color Space Converter MegaCore function inputs and outputs support signed or
unsigned data and 4 to 20 bits per pixel per color plane. Minimum and maximum
guard bands are also supported. The guard bands specify ranges of values that should
never be received by, or transmitted from the MegaCore function. Using output guard
bands allows the output to be constrained, such that it does not enter the guard bands.
Conversions between color spaces are achieved by providing an array of nine
coefficients and three summands that relate the color spaces. These can be set at
compile time, or at run time using the Avalon-MM slave interface.
Given a set of nine coefficients [A0, A1, A2, B0, B1, B2, C0, C1, C2] and a set of three
summands [S0, S1, S2], the output values on channels 0, 1, and 2 (denoted dout_0,
dout_1, and dout_2) are calculated as follows:
User-specified custom constants and the following predefined conversions are
supported:
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dout_0 = (A0 × din_0) + (B0 × din_1) + (C0 × din_2) + S0
dout_1 = (A1 × din_0) + (B1 × din_1) + (C1 × din_2) + S1
dout_2 = (A2 × din_0) + (B2 × din_1) + (C2 × din_2) + S2
where din_0, din_1, and din_2 are inputs read from channels 0, 1, and 2
respectively.
Computer B’G’R’ to CbCrY’: SDTV
CbCrY’: SDTV to Computer B’G’R’
Computer B’G’R’ to CbCrY’: HDTV
CbCrY’: HDTV to Computer B’G’R’
Video and Image Processing Suite User Guide
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