star/image/bild/channel.go
2025-06-13 13:05:50 +08:00

61 lines
1.4 KiB
Go

package bilds
import (
"fmt"
"image"
"github.com/anthonynsimon/bild/channel"
"github.com/spf13/cobra"
)
func extractChannel() *cobra.Command {
var channels string
var cmd = &cobra.Command{
Use: "extract",
Short: "extracts RGBA channels from an input image",
Args: cobra.ExactArgs(2),
Example: "extract --channels rba input.jpg output.png",
Run: func(cmd *cobra.Command, args []string) {
fin := args[0]
fout := args[1]
// Apply takes care of resolving the destination encoder
apply(fin, fout, func(img image.Image) (image.Image, error) {
onlyChannels := []channel.Channel{}
for _, c := range channels {
switch c {
case 'r':
onlyChannels = append(onlyChannels, channel.Red)
case 'g':
onlyChannels = append(onlyChannels, channel.Green)
case 'b':
onlyChannels = append(onlyChannels, channel.Blue)
case 'a':
onlyChannels = append(onlyChannels, channel.Alpha)
default:
return nil, fmt.Errorf("unknown channel alias '%c'", c)
}
}
result := channel.ExtractMultiple(img, onlyChannels...)
return result, nil
})
}}
cmd.Flags().StringVarP(&channels, "channels", "c", "rgba", "the channels to include in the histogram")
return cmd
}
func createChannel() *cobra.Command {
var cmd = &cobra.Command{
Use: "channel",
Short: "channel operations on images",
}
cmd.AddCommand(extractChannel())
return cmd
}