Add timestamp option

camera/camera_cv2.go

@@ -6,6 +6,11 @@ package camera
 import (
 	"fmt"
 	"image"
+	"image/color"
+	"image/draw"
+	"time"
+
+	"github.com/pbnjay/pixfont"
 
 	"github.com/disintegration/imaging"
 	"github.com/gen2brain/go-opencv/opencv"
@@ -36,29 +41,37 @@ func New(opts Options) (camera *Camera, err error) {
 
 // Read reads next frame from camera and returns image.
 func (c *Camera) Read() (img image.Image, err error) {
-	if c.camera.GrabFrame() {
-		c.frame = c.camera.RetrieveFrame(1)
-
-		if c.frame == nil {
-			err = fmt.Errorf("camera: can not retrieve frame")
-			return
-		}
-
-		img = c.frame.ToImage()
-		if c.opts.Rotate == 0 {
-			return
-		}
-
-		switch c.opts.Rotate {
-		case 90:
-			img = imaging.Rotate90(img)
-		case 180:
-			img = imaging.Rotate180(img)
-		case 270:
-			img = imaging.Rotate270(img)
-		}
-	} else {
+	if !c.camera.GrabFrame() {
 		err = fmt.Errorf("camera: can not grab frame")
+		return
+	}
+
+	c.frame = c.camera.RetrieveFrame(1)
+	if c.frame == nil {
+		err = fmt.Errorf("camera: can not retrieve frame")
+		return
+	}
+
+	img = c.frame.ToImage()
+
+	switch c.opts.Rotate {
+	case 90:
+		img = imaging.Rotate90(img)
+	case 180:
+		img = imaging.Rotate180(img)
+	case 270:
+		img = imaging.Rotate270(img)
+	}
+
+	if c.opts.Timestamp {
+		dimg, ok := img.(draw.Image)
+		if !ok {
+			err = fmt.Errorf("camera: %T is not a drawable image type", img)
+			return
+		}
+
+		pixfont.DrawString(dimg, 10, 10, time.Now().Format("2006-01-02 15:04:05"), color.White)
+		img = dimg
 	}
 
 	return