doesn't seem to slow us down significantly ... before:
$ time vips dzsave CMU-1.svs x --layout google --background "243 243 243 255"
real 1m1.940s
user 2m15.004s
sys 0m37.092s
after:
$ time vips dzsave CMU-1.svs x --layout google --background "243 243 243 255"
strip_work: skipping blank tile 176 x 67
strip_work: skipping blank tile 21 x 112
real 1m3.503s
user 2m16.012s
sys 0m40.328s
oops! typo ... also an off-by-one issue for larger stencils
more error checking in interpolators
fix rounding in nohalo/lbb ... they were rounding to nearest in the
interpolator, rather than using floor. This broke assumptions about
stencil position elsewhere. The right way to do centre convention is to offset
the whole input by 0.5 pixels.
small improvements to vips_resize() quality:
* turn down the anti-alias filter a little so we don't smudge out texture
* don't do the final sharpening pass if we skipped the anti-alias filter
* fix a >/>= mixup which meant we didn't sharpen for small resizes
sizealike() / formatalike() and bandsalike() used to just vips_copy() if
the image didn't need any changes ... this was fast, but left a
vips_copy_gen() in the pipeline, wasting a lot of space on the C stack
during recursion.
They now vanish completely if the image is already in the right format.
Since we call them before most image processing operations, and
often all three of them, this saves a lot of C stack, more than x2 even
in simple cases.
There might also be a measureable CPU saving if the operations are very
simple (eg. insert).
See:
http://stackoverflow.com/questions/33658795/difficulty-with-handling-very-large-image-using-vips
the tiff saver was writing all five-band images as CMYKA, even if they
were tagged as srgb ... it now follows the interpretation tag and will
write many alpha channels instead
see https://github.com/jcupitt/libvips/issues/348
thanks sadaqatullahn
we were just rint()ing masks going from float -> int, but this could
give bad results in some cases, with output images becoming darker
or lighter, as individual elemets moved up or down
now we adjust the output scale to try to keep the overall brightness
the same, if we can
see: https://github.com/jcupitt/libvips/issues/344
