jst
9884534579
Cache kernel weights for each row.
...
For each row the convolution kernel is evaluated at fixed positions around "u". By calculating these values once for each row, a huge speedup is achieved.
2014-01-28 18:48:08 +01:00
jst
45368ad0cd
Multiply instead of dividing
2014-01-17 23:14:37 +01:00
jst
314cea6612
Avoid temporaries to save some cycles.
2014-01-17 22:54:15 +01:00
jst
494d8de4e5
Speedup calculation by exploiting the separability of the resizing filter.
...
Should be ~5x faster! More optimization will follow.
before:
> go test -bench .
PASS
Benchmark_BigResizeLanczos3-4 1 2438137093 ns/op
Benchmark_BigResizeLanczos3Lut-4 1 1157612362 ns/op
Benchmark_Reduction-4 2 743950618 ns/op
after:
> go test -bench .
PASS
Benchmark_BigResizeLanczos3-4 5 403685685 ns/op
Benchmark_BigResizeLanczos3Lut-4 10 225539497 ns/op
Benchmark_Reduction-4 10 207004759 ns/op
2013-11-18 19:54:31 +01:00
jst
a85ea9eaa8
Rename Lanczos functions using look-up tables to Lanczos2Lut, Lanczos3Lut and restore Lanczos2, Lanczos3 to give users the choice between higher speed or higher accuracy.
2013-07-08 20:48:20 +02:00
jst
9e5ed35b85
Move splineKernel function nearer to Lanczos definitions.
2013-07-08 20:40:36 +02:00
Geoff Adams
c1b8c4986e
Use a lookup table to speed up the Lanczos kernel
...
Profiling the resize operation using Lanczos kernels showed that most of
the time was spent in the Sin function, which is called twice per
evaluation of the Lanczos kernel. Generating a lookup table and doing a
linear interpolation between table entries speeds up the resize by a
factor of 4.
2013-07-04 02:28:43 -07:00
jst
c37f8f8470
gofmt
2013-04-09 21:59:02 +02:00
jst
62777ac833
Precalculate bicubic factors, save some cycles.
2013-04-09 21:31:31 +02:00
jst
6448fff2ee
Generalize spline based filters
...
This also fixes a quality issue with Mitchell-Netravali: A factor was
missing in the calculation.
2013-04-04 22:32:33 +02:00
jst
82ab8b977c
Make kernel the only dependency of convolution1d
2012-12-13 22:13:37 +01:00
jst
e512502b3c
Use range for more idiomatic Go
2012-12-13 21:55:44 +01:00
jst
bf09bbe0a3
boolToUint: true -> 1
2012-12-11 20:35:47 +01:00
jst
0c69e0e0b7
Change order of fields in filterModel
2012-12-11 20:24:30 +01:00
jst
bf006ca38d
Description added
...
Describe filterModel interface,
Extract bool-to-int method
2012-12-11 20:18:23 +01:00
jst
dd1c157427
Include kernel boundary check
...
Filter kernels should yield Zero if they are evaluted outside their
intended size. Though filterModel.Interpolate doesn't do this by design,
it's better to include it anyways.
2012-12-10 18:56:53 +01:00
jst
3e06045c3f
Speed up computation: Try to avoid Image.At() as much as possible -> specialized color access for some image types
2012-09-21 20:02:25 +02:00
jst
e548f52385
Blur input image during downscaling by scaling the filter kernel to prevent moires in the output image
2012-09-19 21:03:56 +02:00
jst
d0b2b9bc39
Added MitchellNetravali, changed Lanczos a bit
2012-09-19 19:32:00 +02:00
jst
c980eecff5
Small simplification
2012-09-16 09:20:11 +02:00
jst
e96bbe5547
Unify filters and their dependencies
2012-09-15 20:24:14 +02:00
jst
3fc31c95cc
Kernel simplified
2012-09-15 19:30:32 +02:00
jst
eaf9383af0
filters.go simplified
2012-09-14 23:12:05 +02:00
jst
524fd851ea
Casting float to int has the same properties as math.Floor
2012-09-04 22:51:19 +02:00
jst
d93161631c
Use Kernel normalization for more accurate Lanczos resampling. Lanczos2 filter added
2012-09-04 18:49:04 +02:00
jst
339b8fd43a
Speed up calculation by avoiding dynamic casting
2012-09-01 00:21:10 +02:00
jst
14d51db8b4
Changed function signature to include error handling. Filters simplified.
2012-08-08 21:32:51 +02:00
nfnt
428642c9f1
initial commit
2012-08-02 21:59:40 +02:00
