diff --git a/carver.go b/carver.go
index 4933cf4..e7c214f 100644
--- a/carver.go
+++ b/carver.go
@@ -76,7 +76,6 @@ func (c *Carver) set(x, y int, px float64) {
 //     with the minimum pixel value of the neighboring pixels from the previous row.
 func (c *Carver) ComputeSeams(p *Processor, img *image.NRGBA) (*image.NRGBA, error) {
 	var srcImg *image.NRGBA
-	p.DebugMask = image.NewNRGBA(img.Bounds())
 
 	width, height := img.Bounds().Dx(), img.Bounds().Dy()
 	sobel = c.SobelDetector(img, float64(p.SobelThreshold))
@@ -134,6 +133,8 @@ func (c *Carver) ComputeSeams(p *Processor, img *image.NRGBA) (*image.NRGBA, err
 	// which we do not want to be altered by the seam carver,
 	// obtain the white patches and apply it to the sobel image.
 	if len(p.MaskPath) > 0 && p.Mask != nil {
+		p.DebugMask = image.NewNRGBA(img.Bounds())
+
 		for i := 0; i < width*height; i++ {
 			x := i % width
 			y := (i - x) / width
@@ -156,6 +157,8 @@ func (c *Carver) ComputeSeams(p *Processor, img *image.NRGBA) (*image.NRGBA, err
 	// we do not want to be retained in the final image, obtain the white patches,
 	// but this time inverse the colors to black and merge it back to the sobel image.
 	if len(p.RMaskPath) > 0 && p.RMask != nil {
+		p.DebugMask = image.NewNRGBA(img.Bounds())
+
 		for i := 0; i < width*height; i++ {
 			x := i % width
 			y := (i - x) / width
@@ -195,6 +198,7 @@ func (c *Carver) ComputeSeams(p *Processor, img *image.NRGBA) (*image.NRGBA, err
 				face.Col+scale,
 				face.Row+scale,
 			)
+			p.DebugMask = image.NewNRGBA(img.Bounds())
 			draw.Draw(sobel, rect, &image.Uniform{color.White}, image.Point{}, draw.Src)
 			draw.Draw(p.DebugMask, rect, &image.Uniform{color.White}, image.Point{}, draw.Src)
 		}
diff --git a/gui.go b/gui.go
index 0ae3c85..06637d3 100644
--- a/gui.go
+++ b/gui.go
@@ -101,7 +101,7 @@ type Gui struct {
 }
 
 type hudCtrl struct {
-	visible widget.Bool
+	enabled widget.Bool
 	hudType hudControlType
 	title   string
 }
@@ -138,9 +138,9 @@ func (g *Gui) AddHudControl(hudControlType hudControlType, title string, enabled
 	control := &hudCtrl{
 		hudType: hudControlType,
 		title:   title,
-		visible: widget.Bool{},
+		enabled: widget.Bool{},
 	}
-	control.visible.Value = enabled
+	control.enabled.Value = enabled
 	g.huds[hudControlType] = control
 }
 
@@ -253,7 +253,7 @@ func (g *Gui) Run() error {
 			g.process.seams = res.seams
 
 			if mask, ok := g.huds[hudShowDebugMask]; ok {
-				if mask.visible.Value {
+				if mask.enabled.Value && res.mask != nil {
 					bounds := res.img.Bounds()
 					srcBitmap := imop.NewBitmap(bounds)
 					dstBitmap := imop.NewBitmap(bounds)
@@ -381,7 +381,7 @@ func (g *Gui) draw(bgColor color.NRGBA) {
 						}.Layout(gtx)
 
 						if seam, ok := g.huds[hudShowSeams]; ok {
-							if seam.visible.Value {
+							if seam.enabled.Value {
 								tr := f32.Affine2D{}
 								screen := layout.FPt(g.ctx.Constraints.Max)
 								width, height := float32(g.process.img.Bounds().Dx()), float32(g.process.img.Bounds().Dy())
@@ -453,7 +453,7 @@ func (g *Gui) draw(bgColor color.NRGBA) {
 						return g.view.huds.Layout(gtx, len(g.huds),
 							func(gtx layout.Context, index int) D {
 								if hud, ok := g.huds[hudControlType(index)]; ok {
-									checkbox := material.CheckBox(g.theme, &hud.visible, fmt.Sprintf("%v", hud.title))
+									checkbox := material.CheckBox(g.theme, &hud.enabled, fmt.Sprintf("%v", hud.title))
 									checkbox.Size = 20
 									return checkbox.Layout(gtx)
 								}
diff --git a/processor.go b/processor.go
index 63b21c4..4dfcb81 100644
--- a/processor.go
+++ b/processor.go
@@ -24,6 +24,8 @@ var (
 	errs      = make(chan error)
 )
 
+var _ SeamCarver = (*Processor)(nil)
+
 // worker struct contains all the information needed for transferring the resized image to the Gio GUI.
 type worker struct {
 	img   *image.NRGBA
@@ -32,8 +34,6 @@ type worker struct {
 	done  bool
 }
 
-var _ SeamCarver = (*Processor)(nil)
-
 // shrinkFn is a generic function used to shrink an image.
 type shrinkFn func(*image.NRGBA) (*image.NRGBA, error)