Reading Image in Go - go

Question

func (sticky *Sticky) DrawImage(W, H int) (img *image, err error) {
myImage := image.NewRGBA(image.Rect(0, 0, 10, 25))
myImage.Pix[0] = 55 // 1st pixel red
myImage.Pix[1] = 155 // 1st pixel green
return myImage ,nil
}
I am creating an image. I want to read the existing Image and return in this Function. How I can I do that?

Answer 1

Something like this:
func getImageFromFilePath(filePath string) (image.Image, error) {
f, err := os.Open(filePath)
if err != nil {
return nil, err
}
defer f.Close()
image, _, err := image.Decode(f)
return image, err
}
references
https://golang.org/pkg/image/#Decode
https://golang.org/pkg/os/#Open

Answer 2

try this:
package main
import (
"fmt"
"image"
"image/png"
"os"
)
func main() {
// Read image from file that already exists
existingImageFile, err := os.Open("test.png")
if err != nil {
// Handle error
}
defer existingImageFile.Close()
// Calling the generic image.Decode() will tell give us the data
// and type of image it is as a string. We expect "png"
imageData, imageType, err := image.Decode(existingImageFile)
if err != nil {
// Handle error
}
fmt.Println(imageData)
fmt.Println(imageType)
// We only need this because we already read from the file
// We have to reset the file pointer back to beginning
existingImageFile.Seek(0, 0)
// Alternatively, since we know it is a png already
// we can call png.Decode() directly
loadedImage, err := png.Decode(existingImageFile)
if err != nil {
// Handle error
}
fmt.Println(loadedImage)
}
references
https://www.devdungeon.com/content/working-images-go