Marcel Taeumel uploaded a new version of Graphics to project The Trunk: http://source.squeak.org/trunk/Graphics-kfr.529.mcz
==================== Summary ====================
Name: Graphics-kfr.529 Author: kfr Time: 8 July 2022, 9:09:08.988763 am UUID: c82ec469-0674-f04c-9123-0b36fb8eb7d6 Ancestors: Graphics-kfr.528
Floyd Steinberg dither for forms of 1 to 8 bit depth.
=============== Diff against Graphics-kfr.527 ===============
Item was added: + ----- Method: Form>>at:bias: (in category 'processing') ----- + at: aPoint bias: aQuantError + | x y color point oldColor | + x := aPoint x. + y := aPoint y. + + point := (x + 1 min: self width)@ y. + oldColor := self colorAt: point. + color := oldColor + (aQuantError * 0.4375). "7/16" + self colorAt: point put: color. + + point := (x - 1 max: 0)@ (y + 1 min: self height). + oldColor := self colorAt: point. + color := oldColor + (aQuantError * 0.1875)."3/16" + self colorAt: point put: color. + + point := x @ (y + 1 min: self height). + oldColor := self colorAt: point. + color := oldColor + (aQuantError * 0.3125 ) ."5/16" + self colorAt: point put: color. + + point := (x + 1 min: self width) @ (y + 1 min: self height). + oldColor := self colorAt: point. + color := oldColor + (aQuantError * 0.0625 ) ."1/16" + self colorAt: point put: color. + !
Item was added: + ----- Method: Form>>dither: (in category 'processing') ----- + dither: aDepth + | newColor oldColor quantError result | + "Floyd Steinberg dithering for depth 1 to 8 bits" + result := self copy. + (0 to: height) do:[:y| + (0 to: width) do:[:x| + oldColor := (result colorAt: x@y). + newColor := Color colorFromPixelValue: (oldColor pixelValueForDepth: aDepth) depth: aDepth. + result colorAt: x@y put: newColor. + quantError := (oldColor - newColor). + result at: x@y bias: quantError]]. + ^result.!
Item was changed: ----- Method: Form>>processUsingKernel:factor:bias: (in category 'processing') ----- processUsingKernel: filter factor: factor bias: bias + | image result color | - | 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. + color := image colorAt: imageX@imageY. + r := r + (color red * - r := r + ((image colorAt: imageX@imageY) red * (filter at: filterY + 1 at: filterX + 1)). + g := g + (color green * - g := g + ((image colorAt: imageX@imageY) green * (filter at: filterY + 1 at: filterX + 1)). + b := b + (color blue * - b := b + ((image colorAt: imageX@imageY) blue * (filter at: filterY + 1 at: filterX + 1))]].
result colorAt: x@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 !
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