paths safeguard

.gitignore

@@ -1,2 +1,3 @@
 *.jpg
-*.png
+*.png
+output/

blend.go

@@ -8,145 +8,9 @@ import (
 	"log"
 	"math"
 	"os"
-	"runtime"
+	"path"
-	"sync"
 )
 
-// job passed to goroutines. blend color from img1 and img2 at position (x, y)
-type blendColorJob struct {
-	X    int
-	Y    int
-	Img1 image.Image
-	Img2 image.Image
-}
-
-// new color after blend, to apply at position (x, y)
-type blendColorResult struct {
-	X     int
-	Y     int
-	Color color.Color
-}
-
-type blendWorkerPool struct {
-	CpuCores   int
-	Jobs       chan blendColorJob
-	Results    chan blendColorResult
-	WorkerWG   *sync.WaitGroup
-	ConsumerWG *sync.WaitGroup
-}
-
-func (p *blendWorkerPool) InitWorkerPool() {
-	p.CpuCores = runtime.NumCPU()
-	p.Jobs = make(chan blendColorJob, 1)
-	p.Results = make(chan blendColorResult, 1)
-	p.WorkerWG = new(sync.WaitGroup)
-	p.ConsumerWG = new(sync.WaitGroup)
-}
-
-// runs the pool of goroutines
-func (p *blendWorkerPool) RunWorkers(outImg *image.RGBA) {
-	for i := 1; i < p.CpuCores; i++ {
-		p.WorkerWG.Add(1)
-		p.ConsumerWG.Add(1)
-		go p.BlendWorker()
-		go p.SetImageWorker(outImg)
-	}
-}
-
-// blending pixels and assigning them to the output image
-func (p *blendWorkerPool) SendBlendJobs(dimensions image.Rectangle, img1 image.Image, img2 image.Image) {
-	for x := 0; x < dimensions.Max.X; x++ {
-		for y := 0; y < dimensions.Max.Y; y++ {
-			p.Jobs <- blendColorJob{x, y, img1, img2}
-		}
-	}
-	close(p.Jobs)
-}
-
-// goroutine to blend colors at position (x, y) from two images
-func (p *blendWorkerPool) BlendWorker() {
-	defer p.WorkerWG.Done()
-	for j := range p.Jobs {
-		c1 := j.Img1.At(j.X, j.Y)
-		c2 := j.Img2.At(j.X, j.Y)
-		c3 := blendColor(c1, c2)
-		p.Results <- blendColorResult{j.X, j.Y, c3}
-	}
-}
-
-// goroutine to set the new color values at newImage position (x, y)
-func (p *blendWorkerPool) SetImageWorker(newImage *image.RGBA) {
-	defer p.ConsumerWG.Done()
-	for r := range p.Results {
-		newImage.Set(r.X, r.Y, r.Color)
-	}
-}
-
-func (p *blendWorkerPool) BlendImagesMain() {
-	log.Println("Blending the images...")
-
-	p.InitWorkerPool()
-
-	// output image, ready to receive pixel values
-	dimensions := dimensionsToRectangle(ConfigRegister.OutputWidth, ConfigRegister.OutputHeight)
-	outImg := image.NewRGBA(dimensions)
-
-	for i := 1; i < ConfigRegister.Amount; i++ {
-		// get two random images and load them
-		var img1 image.Image
-		if ConfigRegister.BaseImage != "" && i == 1 {
-			img1 = loadImage(ConfigRegister.BaseImage)
-		} else {
-			if i != 1 {
-				img1 = loadImage("output.jpg")
-			} else {
-				img1 = loadImage(getRandomImage())
-			}
-		}
-
-		img2 := loadImage(getRandomImage())
-
-		// pool of workers unionizing, ready to blend a new picture using the power of friendship
-		var pool blendWorkerPool
-		pool.InitWorkerPool()
-
-		// main blending routine
-		pool.BlendImages(img1, img2, outImg)
-
-		encodeImage(outImg)
-	}
-}
-
-func (p *blendWorkerPool) BlendImages(img1 image.Image, img2 image.Image, out *image.RGBA) {
-	dimensions := dimensionsToRectangle(ConfigRegister.OutputWidth, ConfigRegister.OutputHeight)
-
-	// TODO: use a worker pool for those operations ?
-	// resize image
-	img1Resized := resize(img1)
-	img2Resized := resize(img2)
-
-	p.RunWorkers(out)
-
-	p.SendBlendJobs(dimensions, img1Resized, img2Resized)
-
-	// first waitgroup to wait for the results to be ready before closing the channel
-	p.WorkerWG.Wait()
-	close(p.Results)
-
-	// second waitgroup to ensure the encoding doesn't start before the goroutines are done
-	p.ConsumerWG.Wait()
-}
-
-// encode the image
-func encodeImage(imgData *image.RGBA) {
-	outputFile := fmt.Sprintf("%s/%s", ConfigRegister.OutputDir, "output.jpg")
-	out, _ := os.Create(outputFile)
-	defer out.Close()
-	log.Println("Encoding the new image...")
-	jpeg.Encode(out, imgData, nil)
-	log.Println("Done.")
-}
-
 // convert RGBA pixel to grayscale. BT.709 luminosity formula
 func grayscale(pixel color.Color) color.Color {
 	c := color.RGBAModel.Convert(pixel).(color.RGBA)
@@ -250,46 +114,12 @@ func blendColor(color1 color.Color, color2 color.Color) color.Color {
 	return filter(new)
 }
 
-// creates a new rectangle with the min height and width from both images
+// encode the image
-func getMaxDimensions(img1 image.Image, img2 image.Image) image.Rectangle {
+func encodeImage(imgData *image.RGBA) {
-	// get dimensions for both images
+	outputFile := fmt.Sprintf("%s/%s", path.Clean(ConfigRegister.OutputDir), "output.jpg")
-	size1 := img1.Bounds().Size()
+	out, _ := os.Create(outputFile)
-	size2 := img2.Bounds().Size()
+	defer out.Close()
-
+	log.Println("Encoding the new image...")
-	// final image sized from lowest width and height
+	jpeg.Encode(out, imgData, nil)
-	width := int(math.Min(float64(size1.X), float64(size2.X)))
+	log.Println("Done.")
-	height := int(math.Min(float64(size1.Y), float64(size2.Y)))
-
-	// the dimensions, as Points, of the output image
-	upLeft := image.Point{0, 0}
-	lowRight := image.Point{width, height}
-
-	return image.Rectangle{upLeft, lowRight}
-}
-
-// resizes image using dimensions from config register (nearest neighbour interpolation)
-func resize(img image.Image) (resized *image.RGBA) {
-	imgSize := img.Bounds().Size()
-	dimensions := dimensionsToRectangle(ConfigRegister.OutputWidth, ConfigRegister.OutputHeight)
-	xscale := float64(imgSize.X) / float64(dimensions.Max.X)
-	yscale := float64(imgSize.Y) / float64(dimensions.Max.Y)
-	// creates new rescaled image based on a given image dimensions
-	resized = image.NewRGBA(dimensions)
-	// get pixels from the original image
-	for x := 0; x < dimensions.Max.X; x++ {
-		for y := 0; y < dimensions.Max.Y; y++ {
-			xp := int(math.Floor(float64(x) * xscale))
-			yp := int(math.Floor(float64(y) * yscale))
-			pixel := img.At(xp, yp)
-			resized.Set(x, y, pixel)
-		}
-	}
-	return
-}
-
-// returns a Rectangle of dimensions <width>x<height>
-func dimensionsToRectangle(width int, height int) image.Rectangle {
-	upLeft := image.Point{0, 0}
-	lowRight := image.Point{width, height}
-	return image.Rectangle{upLeft, lowRight}
 }

config.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"log"
 	"os"
 	"strconv"
 	"strings"
@@ -48,13 +49,35 @@ func (c *Config) SetOutputDimensions() {
 	c.OutputHeight = height
 }
 
+func (c *Config) CheckPaths() {
+	_, err := os.Stat(c.OutputDir)
+
+	if err != nil {
+		log.Fatal("Output dir does not exist :", c.OutputDir)
+	}
+
+	_, err = os.Stat(c.InputDir)
+
+	if err != nil {
+		log.Fatal("Input dir does not exist :", c.InputDir)
+	}
+
+	if (c.BaseImage != "") {
+		_, err = os.Stat(c.BaseImage)
+
+		if err != nil {
+			log.Fatal("Base image does not exist :", c.BaseImage)
+		}
+	}
+}
+
 func initConfigRegister() {
 	// default seed for the RNG
 	seed := time.Now().UnixNano()
 
 	// command line arguments
 	flag.StringVar(&ConfigRegister.Method, "blending", "darken", "Blending methods : darken, lighten, average, fuckyfun")
-	flag.StringVar(&ConfigRegister.OutputDir, "output", "./", "Output directory")
+	flag.StringVar(&ConfigRegister.OutputDir, "output", "./output", "Output directory")
 	flag.StringVar(&ConfigRegister.InputDir, "input", "/home/gator/Photos", "Input directory. Where to look the images from")
 	flag.StringVar(&ConfigRegister.BaseImage, "base-img", "", "Path to the base image to work with. Random image if not set")
 	flag.StringVar(&ConfigRegister.Dimensions, "dimensions", "1280x1024", "Out image dimensions. <width>x<height>")
@@ -66,6 +89,8 @@ func initConfigRegister() {
 
 	flag.Parse()
 
+	ConfigRegister.CheckPaths()
+
 	// set output's width and height
 	ConfigRegister.SetOutputDimensions()
 }

dimensions.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"image"
+	"math"
+)
+
+// creates a new rectangle with the min height and width from both images
+func getMaxDimensions(img1 image.Image, img2 image.Image) image.Rectangle {
+	// get dimensions for both images
+	size1 := img1.Bounds().Size()
+	size2 := img2.Bounds().Size()
+
+	// final image sized from lowest width and height
+	width := int(math.Min(float64(size1.X), float64(size2.X)))
+	height := int(math.Min(float64(size1.Y), float64(size2.Y)))
+
+	// the dimensions, as Points, of the output image
+	upLeft := image.Point{0, 0}
+	lowRight := image.Point{width, height}
+
+	return image.Rectangle{upLeft, lowRight}
+}
+
+// resizes image using dimensions from config register (nearest neighbour interpolation)
+func resize(img image.Image) (resized *image.RGBA) {
+	imgSize := img.Bounds().Size()
+	dimensions := dimensionsToRectangle(ConfigRegister.OutputWidth, ConfigRegister.OutputHeight)
+	xscale := float64(imgSize.X) / float64(dimensions.Max.X)
+	yscale := float64(imgSize.Y) / float64(dimensions.Max.Y)
+	// creates new rescaled image based on a given image dimensions
+	resized = image.NewRGBA(dimensions)
+	// get pixels from the original image
+	for x := 0; x < dimensions.Max.X; x++ {
+		for y := 0; y < dimensions.Max.Y; y++ {
+			xp := int(math.Floor(float64(x) * xscale))
+			yp := int(math.Floor(float64(y) * yscale))
+			pixel := img.At(xp, yp)
+			resized.Set(x, y, pixel)
+		}
+	}
+	return
+}
+
+// returns a Rectangle of dimensions <width>x<height>
+func dimensionsToRectangle(width int, height int) image.Rectangle {
+	upLeft := image.Point{0, 0}
+	lowRight := image.Point{width, height}
+	return image.Rectangle{upLeft, lowRight}
+}

main.go

@@ -1,8 +1,6 @@
 package main
 
 import (
-	_ "image/jpeg"
-	_ "image/png"
 	"io/ioutil"
 	"log"
 	"math/rand"
@@ -21,9 +19,6 @@ func main() {
 	rand.Seed(ConfigRegister.Seed)
 	log.Println("Seed :", ConfigRegister.Seed)
 
-	// pool of workers unionizing, ready to blend a new picture using the power of friendship
-	var pool blendWorkerPool
-
 	// launch main blending routine
-	pool.BlendImagesMain()
+	BlendImagesMain()
 }

workers.go

@@ -0,0 +1,132 @@
+package main
+
+import (
+	"image"
+	"image/color"
+	"log"
+	"runtime"
+	"sync"
+)
+
+// job passed to goroutines. blend color from img1 and img2 at position (x, y)
+type blendColorJob struct {
+	X    int
+	Y    int
+	Img1 image.Image
+	Img2 image.Image
+}
+
+// new color after blend, to apply at position (x, y)
+type blendColorResult struct {
+	X     int
+	Y     int
+	Color color.Color
+}
+
+type blendWorkerPool struct {
+	CpuCores   int
+	Jobs       chan blendColorJob
+	Results    chan blendColorResult
+	WorkerWG   *sync.WaitGroup
+	ConsumerWG *sync.WaitGroup
+}
+
+func (p *blendWorkerPool) InitWorkerPool() {
+	p.CpuCores = runtime.NumCPU()
+	p.Jobs = make(chan blendColorJob, 1)
+	p.Results = make(chan blendColorResult, 1)
+	p.WorkerWG = new(sync.WaitGroup)
+	p.ConsumerWG = new(sync.WaitGroup)
+}
+
+// runs the pool of goroutines
+func (p *blendWorkerPool) RunWorkers(outImg *image.RGBA) {
+	for i := 1; i < p.CpuCores; i++ {
+		p.WorkerWG.Add(1)
+		p.ConsumerWG.Add(1)
+		go p.BlendWorker()
+		go p.SetImageWorker(outImg)
+	}
+}
+
+// blending pixels and assigning them to the output image
+func (p *blendWorkerPool) SendBlendJobs(dimensions image.Rectangle, img1 image.Image, img2 image.Image) {
+	for x := 0; x < dimensions.Max.X; x++ {
+		for y := 0; y < dimensions.Max.Y; y++ {
+			p.Jobs <- blendColorJob{x, y, img1, img2}
+		}
+	}
+	close(p.Jobs)
+}
+
+// goroutine to blend colors at position (x, y) from two images
+func (p *blendWorkerPool) BlendWorker() {
+	defer p.WorkerWG.Done()
+	for j := range p.Jobs {
+		c1 := j.Img1.At(j.X, j.Y)
+		c2 := j.Img2.At(j.X, j.Y)
+		c3 := blendColor(c1, c2)
+		p.Results <- blendColorResult{j.X, j.Y, c3}
+	}
+}
+
+// goroutine to set the new color values at newImage position (x, y)
+func (p *blendWorkerPool) SetImageWorker(newImage *image.RGBA) {
+	defer p.ConsumerWG.Done()
+	for r := range p.Results {
+		newImage.Set(r.X, r.Y, r.Color)
+	}
+}
+
+func (p *blendWorkerPool) BlendImages(img1 image.Image, img2 image.Image, out *image.RGBA) {
+	dimensions := dimensionsToRectangle(ConfigRegister.OutputWidth, ConfigRegister.OutputHeight)
+
+	// TODO: use a worker pool for those operations ?
+	// resize image
+	img1Resized := resize(img1)
+	img2Resized := resize(img2)
+
+	p.RunWorkers(out)
+
+	p.SendBlendJobs(dimensions, img1Resized, img2Resized)
+
+	// first waitgroup to wait for the results to be ready before closing the channel
+	p.WorkerWG.Wait()
+	close(p.Results)
+
+	// second waitgroup to ensure the encoding doesn't start before the goroutines are done
+	p.ConsumerWG.Wait()
+}
+
+func BlendImagesMain() {
+	log.Println("Blending the images...")
+
+	// output image, ready to receive pixel values
+	dimensions := dimensionsToRectangle(ConfigRegister.OutputWidth, ConfigRegister.OutputHeight)
+	outImg := image.NewRGBA(dimensions)
+
+	for i := 1; i < ConfigRegister.Amount; i++ {
+		// get two random images and load them
+		var img1 image.Image
+		if ConfigRegister.BaseImage != "" && i == 1 {
+			img1 = loadImage(ConfigRegister.BaseImage)
+		} else {
+			if i != 1 {
+				img1 = loadImage("output.jpg")
+			} else {
+				img1 = loadImage(getRandomImage())
+			}
+		}
+
+		img2 := loadImage(getRandomImage())
+
+		// pool of workers unionizing, ready to blend a new picture using the power of friendship
+		var pool blendWorkerPool
+		pool.InitWorkerPool()
+
+		// main blending routine
+		pool.BlendImages(img1, img2, outImg)
+
+		encodeImage(outImg)
+	}
+}