// Applies a Photoshop-like levels operation on an image
func (c *Convertor) LevelImage(img image.Image) image.Image {
imagick.Initialize()
mw := imagick.NewMagickWand()
defer mw.Destroy()
err := mw.ReadImageBlob(c.GetImageBytes(img))
if err != nil {
fmt.Fprintf(os.Stderr, "Error ReadImageBlob: %v\n", err.Error())
return img
}
_, qrange := imagick.GetQuantumRange()
quantumRange := float64(qrange)
inmin := (quantumRange * c.Opts.LevelsInMin) / 255
inmax := (quantumRange * c.Opts.LevelsInMax) / 255
outmin := (quantumRange * c.Opts.LevelsOutMin) / 255
outmax := (quantumRange * c.Opts.LevelsOutMax) / 255
err = mw.LevelImage(inmin, c.Opts.LevelsGamma, inmax)
if err != nil {
fmt.Fprintf(os.Stderr, "Error LevelImageChannel Input: %v\n", err.Error())
return img
}
err = mw.LevelImage(-outmin, 1.0, quantumRange+(quantumRange-outmax))
if err != nil {
fmt.Fprintf(os.Stderr, "Error LevelImageChannel Output: %v\n", err.Error())
return img
}
blob := mw.GetImageBlob()
i, err := c.decodeImage(bytes.NewReader(blob), "levels")
if err != nil {
fmt.Fprintf(os.Stderr, "Error decodeImage: %v\n", err.Error())
return img
}
return i
}
func main() {
// Note that the colours are stored as separate *normalized* RGB components
arglist := []float64{
0, 0,
// RGB black
0, 0, 0,
// The y coordinate is filled in later
0, -1,
// RGB white
1, 1, 1,
}
// arguments for MagickFunctionImage
funclist := []float64{4, -4, 1}
imagick.Initialize()
defer imagick.Terminate()
mw := imagick.NewMagickWand()
defer mw.Destroy()
if err := mw.ReadImage("beijing_md.jpg"); err != nil {
panic(err)
}
// fill in the Y coordinate now that we can get the image dimensions
arglist[6] = float64(mw.GetImageHeight() - 1)
_, quant := imagick.GetQuantumRange()
mw.SigmoidalContrastImage(true, 15, float64(quant)*30/100)
cw := mw.Clone()
defer cw.Destroy()
cw.SparseColorImage(imagick.CHANNELS_RGB, imagick.INTERPOLATE_BARYCENTRIC_COLOR, arglist)
// Do the polynomial function
cw.FunctionImage(imagick.FUNCTION_POLYNOMIAL, funclist)
// -set option:compose:args 15
if err := cw.SetImageArtifact("compose:args", "15"); err != nil {
panic(err)
}
mw.CompositeImage(cw, imagick.COMPOSITE_OP_BLUR, 0, 0)
mw.WriteImage("beijing_model.jpg")
}
func main() {
imagick.Initialize()
defer imagick.Terminate()
/* First step is to create the gel shape:
convert -size 100x60 xc:none \
-fill red -draw 'circle 25,30 10,30' \
-draw 'circle 75,30 90,30' \
-draw 'rectangle 25,15 75,45' \
gel_shape.png
*/
/* Create a wand */
mw := imagick.NewMagickWand()
pw := imagick.NewPixelWand()
dw := imagick.NewDrawingWand()
mw.SetSize(100, 60)
mw.ReadImage("xc:none")
pw.SetColor("red")
dw.SetFillColor(pw)
dw.Circle(25, 30, 10, 30)
dw.Circle(75, 30, 90, 30)
dw.Rectangle(25, 15, 75, 45)
// Now we draw the Drawing wand on to the Magick Wand
mw.DrawImage(dw)
mw.WriteImage("gel_shape.png")
dw.Destroy()
pw.Destroy()
mw.Destroy()
/* Next step is to create the gel highlight:
convert gel_shape.png \
\( +clone -fx A +matte -blur 0x12 -shade 110x0 -normalize \
-sigmoidal-contrast 16,60% -evaluate multiply .5 \
-roll +5+10 +clone -compose Screen -composite \) \
-compose In -composite gel_highlight.png
*/
mw = imagick.NewMagickWand()
mw.ReadImage("gel_shape.png")
mwc := mw.Clone()
mwf, err := mwc.FxImage("A")
if err != nil {
panic(err)
}
mwf.SetImageAlphaChannel(imagick.ALPHA_CHANNEL_DEACTIVATE)
mwf.BlurImage(0, 12)
mwf.ShadeImage(true, 110, 0)
mwf.NormalizeImage()
// The last argument is specified as a percentage on the command line
// but is specified to the function as a percentage of the QuantumRange
_, quant := imagick.GetQuantumRange()
mwf.SigmoidalContrastImage(true, 16, 0.6*float64(quant))
mwf.EvaluateImage(imagick.EVAL_OP_MULTIPLY, 0.5)
mwf.RollImage(5, 10)
mwc.Destroy()
// The +clone operation copies the original but only so that
// it can be used in the following composite operation, so we don't
// actually need to do a clone, just reference the original image.
mwf.CompositeImage(mw, imagick.COMPOSITE_OP_SCREEN, 0, 0)
mw.CompositeImage(mwf, imagick.COMPOSITE_OP_IN, 0, 0)
mw.WriteImage("gel_highlight.png")
mw.Destroy()
mwc.Destroy()
mwf.Destroy()
// Now create the gel border
/*
convert gel_highlight.png \
\( +clone -fx A +matte -blur 0x2 -shade 0x90 -normalize \
-blur 0x2 -negate -evaluate multiply .4 -negate -roll -.5-1 \
+clone -compose Multiply -composite \) \
-compose In -composite gel_border.png
*/
mw = imagick.NewMagickWand()
mw.ReadImage("gel_highlight.png")
mwc = mw.Clone()
mwf, err = mwc.FxImage("A")
if err != nil {
panic(err)
}
mwf.SetImageAlphaChannel(imagick.ALPHA_CHANNEL_DEACTIVATE)
mwf.BlurImage(0, 2)
mwf.ShadeImage(true, 0, 90)
mwf.NormalizeImage()
mwf.BlurImage(0, 2)
mwf.NegateImage(false)
mwf.EvaluateImage(imagick.EVAL_OP_MULTIPLY, 0.4)
mwf.NegateImage(false)
mwf.RollImage(-1, -1)
mwf.CompositeImage(mw, imagick.COMPOSITE_OP_MULTIPLY, 0, 0)
mw.CompositeImage(mwf, imagick.COMPOSITE_OP_IN, 0, 0)
mw.WriteImage("gel_border.png")
mw.Destroy()
mwc.Destroy()
mwf.Destroy()
// and finally the text and shadow effect
/*
convert gel_border.png \
-font Candice -pointsize 24 -fill white -stroke black \
-gravity Center -annotate 0 "Gel" -trim -repage 0x0+4+4 \
\( +clone -background navy -shadow 80x4+4+4 \) +swap \
-background none -flatten gel_button.png
*/
mw = imagick.NewMagickWand()
dw = imagick.NewDrawingWand()
pw = imagick.NewPixelWand()
mw.ReadImage("gel_border.png")
dw.SetFont("Lucida-Handwriting-Italic")
dw.SetFontSize(24)
pw.SetColor("white")
dw.SetFillColor(pw)
pw.SetColor("black")
dw.SetStrokeColor(pw)
dw.SetGravity(imagick.GRAVITY_CENTER)
// It is important to notice here that MagickAnnotateImage renders the text on
// to the MagickWand, NOT the DrawingWand. It only uses the DrawingWand for font
// and colour information etc.
mw.AnnotateImage(dw, 0, 0, 0, "Gel")
mw.TrimImage(0)
mw.ResetImagePage("0x0+4+4")
mwc = mw.Clone()
pw.SetColor("navy")
mwc.SetImageBackgroundColor(pw)
mwc.ShadowImage(80, 4, 4, 4)
mwf = imagick.NewMagickWand()
mwf.AddImage(mwc)
mwf.AddImage(mw)
mw.Destroy()
mwc.Destroy()
pw.SetColor("none")
mwf.SetImageBackgroundColor(pw)
mw = mwf.MergeImageLayers(imagick.IMAGE_LAYER_FLATTEN)
mw.WriteImage("gel_button.png")
mw.Destroy()
mwc.Destroy()
mwf.Destroy()
dw.Destroy()
pw.Destroy()
}