diff --git a/picture.go b/picture.go
index 2eac45c..00b5070 100644
--- a/picture.go
+++ b/picture.go
@@ -21,13 +21,8 @@ type Picture struct {
 // NewPicture creates a new picture from an image.Image.
 func NewPicture(img image.Image, smooth bool) *Picture {
 	// convert the image to NRGBA format
-	var nrgba *image.NRGBA
-	if nrgbaImg, ok := img.(*image.NRGBA); ok {
-		nrgba = nrgbaImg
-	} else {
-		nrgba = image.NewNRGBA(image.Rect(0, 0, img.Bounds().Dx(), img.Bounds().Dy()))
-		draw.Draw(nrgba, nrgba.Bounds(), img, img.Bounds().Min, draw.Src)
-	}
+	nrgba := image.NewNRGBA(image.Rect(0, 0, img.Bounds().Dx(), img.Bounds().Dy()))
+	draw.Draw(nrgba, nrgba.Bounds(), img, img.Bounds().Min, draw.Src)
 
 	var texture *pixelgl.Texture
 	mainthread.Call(func() {