IPSR-VIDEO Altera, IPSR-VIDEO Datasheet - Page 81

• 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

2D FIR Filter
January 2011 Altera Corporation
Calculation Precision
Coefficient Precision
Result to Output Data Type Conversion
You implement each Video and Image Processing MegaCore function to generate
hardware that performs its operations on multiple color planes (typically three).
The 2D FIR Filter performs 2D convolution, using matrices of 3×3, 5×5, and 7×7
coefficients.
The MegaCore function retains full precision throughout the calculation, while
making efficient use of FPGA resources. With suitable coefficients, the MegaCore
function can perform several operations including, but not limited to sharpening,
smoothing and edge detection.
An output pixel is calculated from the multiplication of input pixels in a filter size
grid (kernel) by their corresponding coefficient in the filter.
These values are summed together. Prior to output, this result is scaled, has its
fractional bits removed, is converted to the desired output data type, and is
constrained to a specified range. The position of the output pixel corresponds to the
mid-point of the kernel. If the kernel runs over the edge of an image, the function uses
zeros for the out of range pixels.
The 2D FIR Filter allows its input, output and coefficient data types to be fully
defined. Constraints are 4 to 20 bits per pixel per color plane for input and output, and
up to 35 bits for coefficients.
The 2D FIR Filter supports symmetric coefficients. This reduces the number of
multipliers, resulting in smaller hardware. Coefficients can be set at compile time, or
changed at run time using an Avalon-MM slave interface.
The 2D FIR Filter does not lose calculation precision during the FIR calculation. The
calculation and result data types are derived from the range of input values (as
specified by the input data type, or input guard bands if provided), the coefficient
fixed point type and the coefficient values. If scaling is selected, then the result data
type is scaled up appropriately such that precision is not lost.
The 2D FIR Filter requires a fixed point type to be defined for the coefficients. The
user-entered coefficients (shown as white boxes in the parameter editor) are rounded
to fit in the chosen coefficient fixed point type (shown as purple boxes in the
parameter editor).
After the calculation, the fixed point type of the results must be converted to the
integer data type of the output.
5. Functional Descriptions
Video and Image Processing Suite User Guide