I have been producing a series of diagrams illustrating the effect of
the various rendering intents. I found an SVG of the CIE 1930
chromaticity diagram and dismantled it to provide a background for my
purposes.
The familiar (closed) horseshoe shape is clipped from a rectangular
bitmap of the radial colours of the visual spectrum: going around the
outside border anti-clockwise, the rays from the white point (centre)
to the border are R, Y, G, C, B, M and back to R (i.e. RGB and CMY
interleaved).
Trouble is this doesn't translate to PDF via the Cairo processor, or to
PS and PDF via Ghostscript. The clipping of the bitmap is lost and the
the border path just appears as an object on top of the full
rectangular bitmap. The text labels are aliased in a very ugly way
when I try to output to PNG.
So I thought to convert the bitmap to a pattern, then fill the
horseshoe path with the pattern. No joy. The bitmap turns into a
slightly smaller rectangular pattern that is divided into four unequal
quadrants, that is, it is tiled.
It looks nothing like the demonstration on page 190 (204 of 341) of /Inkscape:
Guide to a Vector Drawing Program/. This shows a picture of a
1920s couple getting into an early MG sports car, then the same picture
used as a fill in a circular object, then the pattern translated to
change the details included in the fill.
If that pic was mine, after changing to a pattern, the pattern would be
smaller than the pixmap, and part of the RH and Bottom sides of the
pixmap would appear as thin bands extending the LH and Top sides of the
pixmap, i.e. the couple and sports car cut up in a way where it would
be impossible to show the full graphic as a pattern fill in any object.
What I really wanted was the bitmap to turn into a single tile pattern,
i.e. a repetition of 1 both vertically and horizontally. Then I could
fill the horseshoe border with the radial colours. It didn't look
anything like the pattern on page 189 top.
So what should I have done?
Regards,
Hedley
Windows XP SP2; Inkscape 0.46; /Inkscape: Guide to a Vector Drawing
Program/, Tavmjong Bah, ed. 0.13 (documenting Inkscape 0.45.1)
--
Hedley Finger
28 Regent Street Camberwell VIC 3124 Australia
Tel. +61 3 9809 1229 Fax. (call phone first)
Mob. (cell) +61 412 461 558
Email. "Hedley Finger" <hfinger@...2483...>