diff --git a/bitmap.go b/bitmap.go
index e6e1674..ca300bc 100644
--- a/bitmap.go
+++ b/bitmap.go
@@ -26,7 +26,6 @@ package robotgo
 import "C"
 
 import (
-	"image"
 	"unsafe"
 
 	"github.com/vcaesar/tt"
@@ -41,18 +40,13 @@ import (
 |______/  |__|     |__|     |__|  |__| /__/     \__\ | _|
 */
 
-// ToBitmap trans C.MMBitmapRef to Bitmap
-func ToBitmap(bit C.MMBitmapRef) Bitmap {
-	bitmap := Bitmap{
-		ImgBuf:        (*uint8)(bit.imageBuffer),
-		Width:         int(bit.width),
-		Height:        int(bit.height),
-		Bytewidth:     int(bit.bytewidth),
-		BitsPixel:     uint8(bit.bitsPerPixel),
-		BytesPerPixel: uint8(bit.bytesPerPixel),
-	}
+// SaveCapture capture screen and save
+func SaveCapture(spath string, args ...int) string {
+	bit := CaptureScreen(args...)
 
-	return bitmap
+	err := SaveBitmap(bit, spath)
+	FreeBitmap(bit)
+	return err
 }
 
 // ToCBitmap trans Bitmap to C.MMBitmapRef
@@ -69,6 +63,11 @@ func ToCBitmap(bit Bitmap) C.MMBitmapRef {
 	return cbitmap
 }
 
+// ToMMBitmapRef trans CBitmap to C.MMBitmapRef
+func ToMMBitmapRef(bit CBitmap) C.MMBitmapRef {
+	return C.MMBitmapRef(bit)
+}
+
 // ToBitmapBytes saves Bitmap to bitmap format in bytes
 func ToBitmapBytes(bit C.MMBitmapRef) []byte {
 	var len C.size_t
@@ -82,11 +81,6 @@ func ToBitmapBytes(bit C.MMBitmapRef) []byte {
 	return bs
 }
 
-// ToMMBitmapRef trans CBitmap to C.MMBitmapRef
-func ToMMBitmapRef(bit CBitmap) C.MMBitmapRef {
-	return C.MMBitmapRef(bit)
-}
-
 // TostringBitmap tostring bitmap to string
 func TostringBitmap(bit C.MMBitmapRef) string {
 	strBit := C.tostring_bitmap(bit)
@@ -99,17 +93,6 @@ func TocharBitmap(bit C.MMBitmapRef) *C.char {
 	return strBit
 }
 
-// ToImage convert C.MMBitmapRef to standard image.Image
-func ToImage(bit C.MMBitmapRef) image.Image {
-	return ToRGBA(bit)
-}
-
-// ToRGBA convert C.MMBitmapRef to standard image.RGBA
-func ToRGBA(bit C.MMBitmapRef) *image.RGBA {
-	bmp1 := ToBitmap(bit)
-	return ToRGBAGo(bmp1)
-}
-
 func internalFindBitmap(bit, sbit C.MMBitmapRef, tolerance float64) (int, int) {
 	pos := C.find_bitmap(bit, sbit, C.float(tolerance))
 	// fmt.Println("pos----", pos)
@@ -337,7 +320,7 @@ func GetPortion(bit C.MMBitmapRef, x, y, w, h int) C.MMBitmapRef {
 // Convert convert the bitmap
 //
 // robotgo.Convert(opath, spath string, type int)
-func Convert(opath, spath string, args ...int) {
+func Convert(opath, spath string, args ...int) string {
 	var mtype = 1
 	if len(args) > 0 {
 		mtype = args[0]
@@ -346,13 +329,7 @@ func Convert(opath, spath string, args ...int) {
 	// C.CString()
 	bitmap := OpenBitmap(opath)
 	// fmt.Println("a----", bit_map)
-	SaveBitmap(bitmap, spath, mtype)
-}
-
-// FreeBitmap free and dealloc the C bitmap
-func FreeBitmap(bitmap C.MMBitmapRef) {
-	// C.destroyMMBitmap(bitmap)
-	C.bitmap_dealloc(bitmap)
+	return SaveBitmap(bitmap, spath, mtype)
 }
 
 // FreeBitmapArr free and dealloc the C bitmap array
diff --git a/bitmap/goBitmap.h b/bitmap/goBitmap.h
index 429fa39..0a205c3 100644
--- a/bitmap/goBitmap.h
+++ b/bitmap/goBitmap.h
@@ -26,12 +26,12 @@ bool bitmap_ready(MMBitmapRef bitmap){
 	return true;
 }
 
-void bitmap_dealloc(MMBitmapRef bitmap){
-	if (bitmap != NULL) {
-		destroyMMBitmap(bitmap);
-		bitmap = NULL;
-	}
-}
+// void bitmap_dealloc(MMBitmapRef bitmap){
+// 	if (bitmap != NULL) {
+// 		destroyMMBitmap(bitmap);
+// 		bitmap = NULL;
+// 	}
+// }
 
 bool bitmap_copy_to_pboard(MMBitmapRef bitmap){
 	MMPasteError err;
diff --git a/cmd/color-pos/main.go b/cmd/color-pos/main.go
index 4383a45..b4ec4f9 100644
--- a/cmd/color-pos/main.go
+++ b/cmd/color-pos/main.go
@@ -7,6 +7,7 @@ import (
 )
 
 func colorPicker() {
+	// click the left mouse button to get the value
 	m := robotgo.AddEvent("mleft")
 	if m {
 		x, y := robotgo.GetMousePos()
diff --git a/robotgo.go b/robotgo.go
index f22a7cc..22387cb 100644
--- a/robotgo.go
+++ b/robotgo.go
@@ -371,12 +371,35 @@ func CaptureImg(args ...int) image.Image {
 	return ToImage(bit)
 }
 
-// SaveCapture capture screen and save
-func SaveCapture(spath string, args ...int) {
-	bit := CaptureScreen(args...)
+// FreeBitmap free and dealloc the C bitmap
+func FreeBitmap(bitmap C.MMBitmapRef) {
+	// C.destroyMMBitmap(bitmap)
+	C.bitmap_dealloc(bitmap)
+}
 
-	SaveBitmap(bit, spath)
-	FreeBitmap(bit)
+// ToBitmap trans C.MMBitmapRef to Bitmap
+func ToBitmap(bit C.MMBitmapRef) Bitmap {
+	bitmap := Bitmap{
+		ImgBuf:        (*uint8)(bit.imageBuffer),
+		Width:         int(bit.width),
+		Height:        int(bit.height),
+		Bytewidth:     int(bit.bytewidth),
+		BitsPixel:     uint8(bit.bitsPerPixel),
+		BytesPerPixel: uint8(bit.bytesPerPixel),
+	}
+
+	return bitmap
+}
+
+// ToImage convert C.MMBitmapRef to standard image.Image
+func ToImage(bit C.MMBitmapRef) image.Image {
+	return ToRGBA(bit)
+}
+
+// ToRGBA convert C.MMBitmapRef to standard image.RGBA
+func ToRGBA(bit C.MMBitmapRef) *image.RGBA {
+	bmp1 := ToBitmap(bit)
+	return ToRGBAGo(bmp1)
 }
 
 /*
diff --git a/screen/goScreen.h b/screen/goScreen.h
index b2d6471..dd22a10 100644
--- a/screen/goScreen.h
+++ b/screen/goScreen.h
@@ -95,6 +95,13 @@ char* get_XDisplay_name(){
 	#endif
 }
 
+void bitmap_dealloc(MMBitmapRef bitmap){
+	if (bitmap != NULL) {
+		destroyMMBitmap(bitmap);
+		bitmap = NULL;
+	}
+}
+
 // capture_screen capture screen
 MMBitmapRef capture_screen(int32_t x, int32_t y, int32_t w, int32_t h){
 	// if () {