func NewHorizontalKernel(width int, f func(x int) float64) Kernel {
if !correct(width) {
utils.Warn("Error: kernel size wrong!")
os.Exit(2)
}
mx := (width - 1) / 2
k := [][]float64{make([]float64, width)}
for x := 0; x < width; x++ {
k[0][x] = f(mx - x)
}
return k
}
func NewVerticalKernel(height int, f func(y int) float64) Kernel {
if !correct(height) {
utils.Warn("Error: kernel size wrong!")
os.Exit(2)
}
my := (height - 1) / 2
k := make([][]float64, height)
for y := 0; y < height; y++ {
k[y] = []float64{f(my - y)}
}
return k
}
func runBlur(cmd *Command, args []string) {
if _, ok := styleNames[blurStyle]; !ok {
utils.Warn("--style must be one of 'clamp', 'ignore' or 'wrap'")
os.Exit(2)
}
style, _ := styleNames[blurStyle]
i := utils.ReadStdin()
if blurBox {
i = blur.Box(i, blurRadius, style)
} else {
i = blur.Gaussian(i, blurRadius, blurGaussian, style)
}
utils.WriteStdout(i)
}
// NewKernel creates a new Kernel of the dimensions given, it is populated by
// the given function which itself is passed the signed x and y offsets from the
// mid point.
func NewKernel(height, width int, f func(x, y int) float64) Kernel {
if !correct(width) || !correct(height) {
utils.Warn("Error: kernel size wrong!")
os.Exit(2)
// should return error really!
}
mx := (width - 1) / 2
my := (height - 1) / 2
k := make([][]float64, height)
for y := 0; y < height; y++ {
k[y] = make([]float64, width)
for x := 0; x < width; x++ {
k[y][x] = f(mx-x, my-y)
}
}
return k
}