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March 16, 2015 09:50
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How to resize a gif image using goroutines
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| package main | |
| import ( | |
| "fmt" | |
| "github.com/disintegration/imaging" | |
| "image" | |
| "image/draw" | |
| "image/gif" | |
| "os" | |
| "runtime" | |
| "strconv" | |
| "strings" | |
| ) | |
| type Result struct { | |
| Paletted *image.Paletted | |
| Thumb *Thumb | |
| Position int | |
| } | |
| type Thumb struct { | |
| Image *image.NRGBA | |
| Width int | |
| Height int | |
| } | |
| // command source.gif {width}x{height} destination.gif | |
| func main() { | |
| // use all CPU cores for maximum performance | |
| runtime.GOMAXPROCS(runtime.NumCPU()) | |
| fmt.Println(os.Args) | |
| inputFile, err := os.Open(os.Args[1]) | |
| dimension := os.Args[2] | |
| splits := strings.Split(dimension, "x") | |
| width, _ := strconv.Atoi(splits[0]) | |
| height, _ := strconv.Atoi(splits[1]) | |
| if err != nil { | |
| panic(err) | |
| } | |
| defer inputFile.Close() | |
| g, err := gif.DecodeAll(inputFile) | |
| if err != nil { | |
| panic(err) | |
| } | |
| length := len(g.Image) | |
| done := make(chan *Result) | |
| images := make([]*image.Paletted, length) | |
| processed := 0 | |
| for i := range g.Image { | |
| go func(paletted *image.Paletted, width int, height int, position int) { | |
| done <- &Result{ | |
| Thumb: &Thumb{ | |
| Image: imaging.Thumbnail(paletted, width, height, imaging.NearestNeighbor), | |
| Width: width, | |
| Height: height, | |
| }, | |
| Position: position, | |
| Paletted: image.NewPaletted(image.Rect(0, 0, width, height), paletted.Palette), | |
| } | |
| }(g.Image[i], width, height, i) | |
| } | |
| for { | |
| result := <-done | |
| draw.Draw(result.Paletted, image.Rect(0, 0, result.Thumb.Width, result.Thumb.Height), result.Thumb.Image, image.Pt(0, 0), draw.Src) | |
| images[result.Position] = result.Paletted | |
| processed++ | |
| if processed == length { | |
| break | |
| } | |
| } | |
| g.Image = images | |
| outputFile, err := os.Create(os.Args[3]) | |
| if err != nil { | |
| panic(err) | |
| } | |
| defer outputFile.Close() | |
| err = gif.EncodeAll(outputFile, g) | |
| if err != nil { | |
| panic(err) | |
| } | |
| } |
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