Wouldn't it be better to use FFT?

Levente

On Fri, 17 Apr 2015, commits at source.squeak.org wrote:

> Tim Felgentreff uploaded a new version of Graphics to project The Trunk:
> http://source.squeak.org/trunk/Graphics-tfel.310.mcz
>
> ==================== Summary ====================
>
> Name: Graphics-tfel.310
> Author: tfel
> Time: 17 April 2015, 2:37:38.42 pm
> UUID: dcfe87bc-46ca-c04e-b99b-5a711f8a8c9e
> Ancestors: Graphics-tk.309
>
> add convolution to forms and some common kernels for blurring, sharpening and so on
>
> =============== Diff against Graphics-tk.309 ===============
>
> Item was added:
> + ----- Method: Form>>approxGaussianBlur (in category 'processing') -----
> + approxGaussianBlur
> +
> + 	^ self processUsingKernel: (Matrix rows: 3 columns: 3 contents: #(
> + 		 1 2 1
> + 		 2 4 2
> + 		 1 2 1
> + 	) *  0.0625)!
>
> Item was added:
> + ----- Method: Form>>edgeDetect (in category 'processing') -----
> + edgeDetect
> +
> + 	^ self processUsingKernel: (Matrix rows: 3 columns: 3 contents: #(
> + 		-1 -1 -1
> + 		-1  8 -1
> + 		-1 -1 -1
> + 	))!
>
> Item was added:
> + ----- Method: Form>>emboss (in category 'processing') -----
> + emboss
> +
> + 	^ self processUsingKernel: (Matrix rows: 3 columns: 3 contents: #(
> + 		-2 -1  0
> + 		-1  1  1
> + 		 0  1  2
> + 	))!
>
> Item was added:
> + ----- Method: Form>>processUsingKernel: (in category 'processing') -----
> + processUsingKernel: filter
> +
> + 	^ self processUsingKernel: filter factor: 1.0 bias: 0.0!
>
> Item was added:
> + ----- Method: Form>>processUsingKernel:factor:bias: (in category 'processing') -----
> + processUsingKernel: filter factor: factor bias: bias
> + 	| image result |
> +
> + 	image := self.
> + 	result := Form extent: image extent depth: image depth.
> +
> + 	0 to: image height - 1 do: [:y |
> + 		0 to: image width - 1 do: [:x |
> + 			| r g b |
> + 			r := g := b := 0.0.
> +
> + 			0 to: filter rowCount - 1 do: [:filterY |
> + 				0 to: filter columnCount - 1 do: [:filterX |
> + 					| imageX imageY |
> + 					imageX := (x - (filter columnCount // 2) + filterX + image width) \\
> + 								image width.
> + 					imageY := (y - (filter rowCount // 2) + filterY + image height) \\
> + 								image height.
> + 					r := r + ((image colorAt: imageX at imageY) red *
> + 								(filter at: filterY + 1 at: filterX + 1)).
> + 					g := g + ((image colorAt: imageX at imageY) green *
> + 								(filter at: filterY + 1 at: filterX + 1)).
> + 					b := b + ((image colorAt: imageX at imageY) blue *
> + 								(filter at: filterY + 1 at: filterX + 1))]].
> +
> + 			result colorAt: x at y put: (Color
> + 				r: ((factor * r + bias) min: 1.0 max: 0.0)
> + 				g: ((factor * g + bias) min: 1.0 max: 0.0)
> + 				b: ((factor * b + bias) min: 1.0 max: 0.0))]].
> + 	^ result
> + !
>
> Item was added:
> + ----- Method: Form>>sharpen (in category 'processing') -----
> + sharpen
> +
> + 	^ self processUsingKernel: (Matrix rows: 3 columns: 3 contents: #(
> + 		 0 -1  0
> + 		-1  5 -1
> + 		 0 -1  0
> + 	))!
>
>
>