package image
func NewAlpha(r Rectangle) *Alpha
NewAlpha returns a new Alpha with the given bounds.
Golang image.NewAlpha function usage examples
Example 1:
package main
import (
"fmt"
"image"
"image/jpeg"
"os"
)
func init() {
// damn important or else At(), Bounds() functions will
// caused memory pointer error!!
image.RegisterFormat("jpeg", "jpeg", jpeg.Decode, jpeg.DecodeConfig)
}
func main() {
imgfile, err := os.Open("./img.jpg")
if err != nil {
fmt.Println("img.jpg file not found!")
os.Exit(1)
}
defer imgfile.Close()
img, _, err := image.Decode(imgfile)
fmt.Println(img.At(10, 10))
bounds := img.Bounds()
fmt.Println(bounds)
canvas := image.NewAlpha(bounds) // <-- here
// is this image opaque
op := canvas.Opaque()
fmt.Println(op)
}
Sample output :
{255 128 128}
(0,0)-(760,479)
false
Example 2:
inFile, openErr := os.Open(GIFFileInPath)
if openErr != nil {
fmt.Printf("couldn't open %v: %v\n", inPath, openErr)
os.Exit(1)
}
decoded, _, decodeErr := image.Decode(inFile)
inFile.Close()
// optimize image, converting colorspace if requested
bounds := decoded.Bounds()
switch optimizee := decoded.(type) {
case *image.Alpha16:
converted := image.NewAlpha(bounds)
...
Reference :
http://golang.org/pkg/image/#NewAlpha
