--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/IMGmanip.go	Sat Oct 01 11:16:31 2016 +0900
@@ -0,0 +1,215 @@
+/* Image Manipulator - ver 0.2 ( Last Change: 2016-08-21 Sun 09:51:52.) */
+package main
+
+import(
+	"errors"
+	"flag"
+	"fmt"
+	"image"
+	"image/jpeg"
+	"image/png"
+	"io"
+	"os"
+	"strings"
+	"strconv"
+)
+
+func main() {
+	ver := "0.2"
+
+	// arguments
+	kind   := flag.String( "t",    "", "file type : jpeg / png" )
+	resize := flag.String( "s",    "", "new size  : 600x800 / 320x0 / ..." )
+	crop   := flag.String( "c",    "", "crop size : 300x200+10+35" )
+	angle  := flag.Uint(   "r",     0, "rotate    : 90 / 180 / 270" )
+
+	flag.Parse()
+	if flag.NFlag() == 0 {
+		fmt.Fprintf( os.Stderr, "\n=== Image-Manipulator - version %s ===", ver )
+		fmt.Fprintf( os.Stderr, "\n$ imgmanip [option parameter] < infile > outfile\n" )
+		flag.PrintDefaults()
+		os.Exit( 1 )
+	}
+
+	// convert
+	if *kind != "" {
+		err := Convert( os.Stdin, os.Stdout, *kind ); if err != nil {
+			fmt.Fprintf( os.Stderr, "%s: %v\n", *kind, err )
+			os.Exit( 1 )
+		}
+		return
+	}
+
+	// resize
+	if *resize != "" {
+		err := Resize( os.Stdin, os.Stdout, *resize ); if err != nil {
+			fmt.Fprintf( os.Stderr, "resize: %v\n", err )
+			os.Exit( 1 )
+		}
+		return
+	}
+
+	// crop
+	if *crop != "" {
+		err := Crop( os.Stdin, os.Stdout, *crop ); if err != nil {
+			fmt.Fprintf( os.Stderr, "crop: %v\n", err )
+			os.Exit( 1 )
+		}
+		return
+	}
+
+	// rotate
+	if *angle != 0 {
+		err := Rotate( os.Stdin, os.Stdout, *angle ); if err != nil {
+			fmt.Fprintf( os.Stderr, "rotate: %v\n", err )
+			os.Exit( 1 )
+		}
+		return
+	}
+}
+
+func Convert( in io.Reader, out io.Writer, kind string ) error {
+
+	img, _, err := image.Decode( in ); if err != nil {
+		return err
+	}
+
+	switch kind {
+	case "jpeg":
+		return jpeg.Encode( out, img, &jpeg.Options{ Quality: 100 } )
+	case "png":
+		return png.Encode( out, img )
+	}
+
+	return errors.New( "image-type is not supported")
+}
+
+func Resize( in io.Reader, out io.Writer, size string ) error {
+
+	img, kind, err := image.Decode( in ); if err != nil {
+		return err
+	}
+	srcW := img.Bounds().Max.X
+	srcH := img.Bounds().Max.Y
+
+	wh := strings.Split( size, "x" )
+	w, err := strconv.Atoi( wh[0] ); if err != nil || w < 0 {
+		return errors.New( "invalid width" )
+	}
+	h, err := strconv.Atoi( wh[1] ); if err != nil || h < 0 {
+		return errors.New( "invalid height" )
+	}
+	if w == 0 && h == 0 {
+		return errors.New( "invalid size" )
+	}
+	if w == 0 {
+		w = h * srcW / srcH
+	}
+	if h == 0 {
+		h = w * srcH / srcW
+	}
+
+	dst := image.NewNRGBA( image.Rect( 0, 0, w, h ) )
+	for x := 0; x < w; x++ {
+		for y := 0; y < h; y++ {
+			dst.Set( x, y, img.At( x * srcW / w, y * srcH / h ) )
+		}
+	}
+
+	switch kind {
+	case "jpeg":
+		return jpeg.Encode( out, dst, &jpeg.Options{ Quality: 100 } )
+	case "png":
+		return png.Encode( out, dst )
+	}
+
+	return errors.New( "image-type is not supported")
+}
+
+func Crop( in io.Reader, out io.Writer, geo string ) error {
+
+	img, kind, err := image.Decode( in ); if err != nil {
+		return err
+	}
+	srcW := img.Bounds().Max.X
+	srcH := img.Bounds().Max.Y
+
+	buf := strings.Split( geo, "x" )
+	w, err := strconv.Atoi( buf[0] ); if err != nil || w < 0 || w > srcW {
+		return errors.New( "invalid width" )
+	}
+	buf = strings.Split( buf[1], "+" )
+	h, err := strconv.Atoi( buf[0] ); if err != nil || h < 0 || h > srcH {
+		return errors.New( "invalid height" )
+	}
+	x0, err := strconv.Atoi( buf[1] ); if err != nil || x0 < 0 {
+		return errors.New( "invalid x" )
+	}
+	y0, err := strconv.Atoi( buf[2] ); if err != nil || y0 < 0 {
+		return errors.New( "invalid y" )
+	}
+
+	var dst *image.NRGBA
+
+	dst = image.NewNRGBA( image.Rect( 0, 0, w, h ) )
+	for x := 0; x < x0 + w; x++ {
+		for y := 0; y < y0 + h; y++ {
+			dst.Set( x, y, img.At( x0 + x, y0 + y ) )
+		}
+	}
+
+	switch kind {
+	case "jpeg":
+		return jpeg.Encode( out, dst, &jpeg.Options{ Quality: 100 } )
+	case "png":
+		return png.Encode( out, dst )
+	}
+
+	return errors.New( "image-type is not supported")
+}
+
+func Rotate( in io.Reader, out io.Writer, angle uint ) error {
+
+	img, kind, err := image.Decode( in ); if err != nil {
+		return err
+	}
+	srcW := img.Bounds().Max.X
+	srcH := img.Bounds().Max.Y
+
+	var dst *image.NRGBA
+	switch angle {
+	case  90:
+		dst = image.NewNRGBA( image.Rect( 0, 0, srcH, srcW ) )
+		for x := 0; x < srcH; x++ {
+			for y := 0; y < srcW; y++ {
+				dst.Set( x, y, img.At( y, srcH - x ) )
+			}
+		}
+	case 180:
+		dst = image.NewNRGBA( image.Rect( 0, 0, srcW, srcH ) )
+		for x := 0; x < srcW; x++ {
+			for y := 0; y < srcH; y++ {
+				dst.Set( x, y, img.At( srcW - x, srcH - y ) )
+			}
+		}
+	case 270:
+		dst = image.NewNRGBA( image.Rect( 0, 0, srcH, srcW ) )
+		for x := 0; x < srcH; x++ {
+			for y := 0; y < srcW; y++ {
+				dst.Set( x, y, img.At( y, x ) )
+			}
+		}
+	default:
+		return errors.New( "bad angle" )
+	}
+
+	switch kind {
+	case "jpeg":
+		return jpeg.Encode( out, dst, &jpeg.Options{ Quality: 100 } )
+	case "png":
+		return png.Encode( out, dst )
+	}
+
+	return errors.New( "image-type is not supported")
+}
+