Image manipulation in Golang

Question

I have the following:

1. Background image (bi)
2. Image1 (i1)
3. Image3 (i2)

I want to position i1 and i2 over bi with some angle and then produce a final image. I have x and y axis value for i1 and i2 and their expected rotation angle. i1 and i2 may partially overlay on each other. but I have z index for i1 and i2 to know, if in case they overlap then who will be in foreground.

I am trying to achieve this in Golang.
http://golang.org/doc/articles/image_draw.html seems to do this. Anyone knows any similar example of code, that may help. Or can you show me couple of lines in Golang as a pseudo program?

Thanks.

Answer 1

Not sure exactly what you are looking for and I haven't worked with the image package much at all ... but just following the sample code and using graphics-go package (it works for me), I was able to do something at least.

package main

import (
    "fmt"
    "os"
    "image/draw"
    "image"
    "image/jpeg"
    "code.google.com/p/graphics-go/graphics"
)

func main() {
    fImg1, _ := os.Open("arrow1.jpg")
    defer fImg1.Close()
    img1, _, _ := image.Decode(fImg1)

    fImg2, _ := os.Open("arrow2.jpg")
    defer fImg2.Close()
    img2, _, _ := image.Decode(fImg2)

    m := image.NewRGBA(image.Rect(0, 0, 800, 600))
    draw.Draw(m, m.Bounds(), img1, image.Point{0,0}, draw.Src)
    //draw.Draw(m, m.Bounds(), img2, image.Point{-200,-200}, draw.Src)
    graphics.Rotate(m, img2, &graphics.RotateOptions{3.5})

    toimg, _ := os.Create("new.jpg")
    defer toimg.Close()

    jpeg.Encode(toimg, m, &jpeg.Options{jpeg.DefaultQuality})
}