SH7205 Datasheet, PDF (1464/1904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 26 2D Graphics Engine (2DG)
Examples of the settings for starting phase in resizing for reduction (magnification by half) are
given below (the explanation only applied to the horizontal direction). In figure 26.34, S0 to S4
are source pixels and D0 to D2 are the destination pixels interpolated for the given magnification
factor. Destination pixels (1) and (2) indicate the phases for interpolation of the destination pixels
for starting phase settings of H'0 and H'800, respectively.
Source pixels
S0
S1
S2
S3
S4
1
HDLT_INTGR & HDLT_DCML
HDLT_INTGR & HDLT_DCML
Destination
D0
D1
D2
pixels (1)
When the starting phase = H'000
(H1PHS_DCML = 000(H))
HDLT_INTGR & HDLT_DCML
Destination
D0
D1
pixels (2)
When the starting phase = H'800
(H1PHS_DCML = 800(H))
Figure 26.34 Settings for Starting Phase in Resizing for Reduction (Magnification by Half)
The fractional components of the starting phase (the H1PHS_DCML and V1PHS_DCML bits) are
asset for an interval of one between source pixels. In figure 26.34, destination pixels (1) shows the
positions of interpolation for the destination pixels when the starting phase (H1PHS_DCML) =
H'000, where the position of the leading pixel (D0) is generated with a phase of zero. Destination
pixels (2) shows the positions of interpolation for the destination pixels when the starting phase
(H1PHS_DCML) = H'800, where the position of the leading pixel (D0) is advanced by only the
starting phase (H1PHS_DCML), and the starting phase is maintained in subsequent interpolation.
The proportions of the two source pixels for reference can be varied by attaching or not attaching a
starting phase in this way.
The method can thus be used to alleviate the effects of the omission of pixels. Figure 26.35 shows
examples of the results when a starting phase is and is not attached in resizing for reduction
(magnification by half).
Rev. 1.00 Mar. 25, 2008 Page 1432 of 1868
REJ09B0372-0100