Esempio n. 1
0
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)
}
Esempio n. 2
0
// UnsharpMask sharpens the given Image using the unsharp mask technique.
// Basically the image is blurred, then subtracted from the original for
// differences above the threshold value.
func UnsharpMask(in image.Image, radius int, sigma, amount, threshold float64) image.Image {
	blurred := blur.Gaussian(in, radius, sigma, blur.IGNORE)
	bounds := in.Bounds()
	out := image.NewRGBA(bounds)

	// Absolute difference between a and b, returns float64 between 0 and 1.
	diff := func(a, b float64) float64 {
		if a > b {
			return a - b
		}
		return b - a
	}

	for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
		for x := bounds.Min.X; x < bounds.Max.X; x++ {
			ar, ag, ab, aa := utils.RatioRGBA(in.At(x, y))
			br, bg, bb, _ := utils.RatioRGBA(blurred.At(x, y))

			if diff(ar, br) >= threshold {
				ar = amount*(ar-br) + ar
			}

			if diff(ag, bg) >= threshold {
				ag = amount*(ag-bg) + ag
			}

			if diff(ab, bb) >= threshold {
				ab = amount*(ab-bb) + ab
			}

			out.Set(x, y, color.NRGBA{
				uint8(utils.Truncatef(ar * 255)),
				uint8(utils.Truncatef(ag * 255)),
				uint8(utils.Truncatef(ab * 255)),
				uint8(aa * 255),
			})
		}
	}

	return out
}