sobel

func Abs ¶

func Abs(x int) uint32

Abs returns the absolute value of the given int.

func Filter ¶

func Filter(img image.Image, flt FilterType) *image.Gray

func FilterGray ¶

func FilterGray(grayImg *image.Gray, flt FilterType) (filtered *image.Gray)

for better optimization in case of input gray image

func FilterGrayFast ¶

func FilterGrayFast(grayImg *image.Gray, flt FilterType) (filtered *image.Gray)

Benchmark_FilterGray 27336411 ns/op Benchmark_FilterGrayFast 19521755 ns/op for better optimization in case of input gray image

func FilterGrayMath ¶

func FilterGrayMath(grayImg *image.Gray) (filtered *image.Gray)

func FilterGraySimd ¶

func FilterGraySimd(grayImg *image.Gray) (filtered *image.Gray)

BenchmarkIT/Benchmark_FilterGraySimd-2 1032 1499811 ns/op malloc

BenchmarkIT/Benchmark_FilterGraySimd-2 501 2000184 ns/op dstX := make([]uint16, dstSize) dstXC := (*C.uint8_t)(unsafe.Pointer(&dstX[0]))

BenchmarkIT/Benchmark_FilterGraySimd-2 276 4853208 ns/op add flited filling

func FilterMath ¶

func FilterMath(img image.Image, flt FilterType) *image.Gray

func FilterSimd ¶

func FilterSimd(img image.Image, flt FilterType) *image.Gray

func FloorSqrt ¶

func FloorSqrt(x uint32) (ans uint32)

https://www.geeksforgeeks.org/square-root-of-an-integer/ Time Complexity: O(Log x)

func FloorSqrtFast ¶

func FloorSqrtFast(x uint32) (ans uint32)

func ISqrt ¶

func ISqrt(n uint32) (x uint32)

ISqrt returns floor(sqrt(n)). Typical run time is few hundreds of ns. https://gitlab.com/cznic/mathutil/-/blob/master/mathutil.go

func ToGrayscale ¶

func ToGrayscale(img image.Image) *image.Gray