This means that only Kernel values have a NewScaler method, which
re-uses computation when scaling multiple images of the same dst and src
dimensions. The NearestNeighbor and ApproxBiLinear scalers don't get any
pre-computation to re-use, so don't need a NewScaler method just to
satisfy the previous Interpolator interface. As a small bonus, NN.Scale
and ABL.Scale should no longer allocate on the fast paths.
This change is consistent the upcoming Transformer method, so that the
Interpolator interface will be
type Interpolator interface {
Scale(etc)
Transform(etc)
}
instead of
type Interpolator interface {
NewScaler(etc) Scaler
Transform(etc)
}
I don't have a good theory for why the "func (ablInterpolator)
scale_RGBA_RGBA" benchmark is such a dramatic improvement, but at least
it's in the right direction. I'm calling the other benchmark changes as
noise.
benchmark old ns/op new ns/op delta
BenchmarkScaleLargeDownNN 3233406 3169060 -1.99%
BenchmarkScaleLargeDownAB 12018178 12011348 -0.06%
BenchmarkScaleLargeDownBL 1420827834 1409335695 -0.81%
BenchmarkScaleLargeDownCR 2820669690 2795534035 -0.89%
BenchmarkScaleDownNN 866628 869241 +0.30%
BenchmarkScaleDownAB 3175963 3216041 +1.26%
BenchmarkScaleDownBL 26639767 26677003 +0.14%
BenchmarkScaleDownCR 51720996 51621628 -0.19%
BenchmarkScaleUpNN 42758485 43258611 +1.17%
BenchmarkScaleUpAB 156693813 156943367 +0.16%
BenchmarkScaleUpBL 69511444 69621698 +0.16%
BenchmarkScaleUpCR 124530191 124885601 +0.29%
BenchmarkScaleSrcGray 8992205 9129321 +1.52%
BenchmarkScaleSrcNRGBA 9807837 9894466 +0.88%
BenchmarkScaleSrcRGBA 1333188 1104282 -17.17%
BenchmarkScaleSrcUniform 1147788 1162488 +1.28%
BenchmarkScaleSrcYCbCr 12164542 12305373 +1.16%
Change-Id: I2aee6c392eb7437e843260775aed97ce145b4d47
Reviewed-on: https://go-review.googlesource.com/6556
Reviewed-by: Rob Pike <r@golang.org>
This will lessen the diff in a follow-up change.
Change-Id: I67257b935e4b5fc6fcc462c83910a3f09f26702f
Reviewed-on: https://go-review.googlesource.com/6554
Reviewed-by: David Symonds <dsymonds@golang.org>
Optimizing this code path will be follow-up changes.
Change-Id: Ifece6c7d3685bb8f2d20cf8828a121c9ff346434
Reviewed-on: https://go-review.googlesource.com/6238
Reviewed-by: Rob Pike <r@golang.org>
Adding fast paths for concrete dst and src image types will be follow-up
changes.
Change-Id: Ib23e3cc46d9c7a52ebd5eddfbad09177b0b421af
Reviewed-on: https://go-review.googlesource.com/5417
Reviewed-by: Rob Pike <r@golang.org>
This is just a copy/paste/rename in anticipation of automatically
generating fast-path code for specific dst-image types and src-image
types, a la the standard library's image/draw package.
Change-Id: If6385b347cb5e1d134b0ce841ef38ed4450a6fef
Reviewed-on: https://go-review.googlesource.com/5252
Reviewed-by: David Symonds <dsymonds@golang.org>
