User guide

13–6 Chapter 13: Color Space Converter MegaCore Function
Parameter Settings
Video and Image Processing Suite January 2013 Altera Corporation
User Guide
Table 13–4 lists the Color Space Converter MegaCore function parameters in the
Operands Page.
Convert from signed
to unsigned by
Saturating to minimum value at stage 4,
Replacing negative with absolute value
Choose the method of signed to unsigned conversion for
the results.
Notes to Table 13–3:
(1) When Guard bands are on, the MegaCore function never receives or sends data outside of the range specified by Min and Max.
(2) You can specify a higher precision output by increasing Bits per pixel per color plane and Move binary point right.
Table 13–3. Color Space Converter Parameter Settings Tab, General Page (Part 2 of 2)
Parameter Value Description
Table 13–4. Color Space Converter Parameter Settings Tab, Operands Page (Part 1 of 2)
Parameter Value Description
Color model
conversion
(1)
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’, Studio B’G’R’ to
CbCrY’: SDTV, CbCrY’: SDTV to
Studio B’G’R’, Studio B’G’R’ to
CbCrY’: HDTV, CbCrY’: HDTV to
Studio B’G’R’, IQY' to Computer
B'G'R', Computer B'G'R' to IQY',
UVY' to Computer B'G'R'
Computer B'G'R' to UVY',
Custom
Specifies a predefined set of coefficients and summands to use for
color model conversion at compile time. Alternatively, you can select
Custom and create your own custom set by modifying the din_0,
din_1, and din_2 coefficients for dout_0, dout_1, and dout_2
separately.
The values are assigned in the order indicated by the conversion
name. For example, if you select Computer B’G’R’ to CbCrY’: SDTV,
then din_0 = B’, din_1 = G’, din_2 = R’, dout_0 = Cb, dout_1 = Cr, and
dout_2 = Y’.
Run-time
controlled
On or Off Turn on to enable run-time control of the conversion values.
Coefficients
and
Summands
A0, B0, C0, S0
A1, B1, C1, S1
A2, B2, C2, S2
12 fixed-point values
Each coefficient or summand is represented by a white cell with a
purple cell underneath. The value in the white cell is the desired value,
and is editable. The value in the purple cell is the actual value,
determined by the fixed-point type specified. The purple cells are not
editable. You can create a custom coefficient and summand set by
specifying one fixed-point value for each entry.
You can paste custom coefficients into the table from a spreadsheet
(such as Microsoft Excel). Blank lines must be left in your input data
for the non-editable cells.
Coefficients:
Signed
(2)
On or Off
Turn on to set the fixed point type used to store the constant
coefficients as having a sign bit.
Coefficients:
Integer bits
(2)
0–16, Default = 0
Specifies the number of integer bits for the fixed point type used to
store the constant coefficients.
Summands:
Signed
(2)
On or Off
Turn on to set the fixed point type used to store the constant
summands as having a sign bit.
Summands:
Integer bits
(2)
0–22, Default = 8
Specifies the number of integer bits for the fixed point type used to
store the constant summands.