diff --git a/internal/atlas/image.go b/internal/atlas/image.go
index a940949ae..eb0225983 100644
--- a/internal/atlas/image.go
+++ b/internal/atlas/image.go
@@ -572,29 +572,32 @@ func (i *Image) replacePixels(pix []byte, x, y, width, height int) {
 	i.backend.restorable.ReplacePixels(pixb, x, y, pw, ph)
 }
 
-func (img *Image) Pixels(graphicsDriver graphicsdriver.Graphics) ([]byte, error) {
+func (img *Image) ReadPixels(graphicsDriver graphicsdriver.Graphics, pixels []byte) error {
 	backendsM.Lock()
 	defer backendsM.Unlock()
 
 	x := img.paddingSize()
 	y := img.paddingSize()
 
-	bs := make([]byte, 4*img.width*img.height)
+	if got, want := len(pixels), 4*img.width*img.height; got != want {
+		return fmt.Errorf("atlas: len(pixels) must be %d but %d", want, got)
+	}
+
 	idx := 0
 	for j := y; j < y+img.height; j++ {
 		for i := x; i < x+img.width; i++ {
 			r, g, b, a, err := img.at(graphicsDriver, i, j)
 			if err != nil {
-				return nil, err
+				return err
 			}
-			bs[4*idx] = r
-			bs[4*idx+1] = g
-			bs[4*idx+2] = b
-			bs[4*idx+3] = a
+			pixels[4*idx] = r
+			pixels[4*idx+1] = g
+			pixels[4*idx+2] = b
+			pixels[4*idx+3] = a
 			idx++
 		}
 	}
-	return bs, nil
+	return nil
 }
 
 func (i *Image) at(graphicsDriver graphicsdriver.Graphics, x, y int) (byte, byte, byte, byte, error) {
diff --git a/internal/atlas/image_test.go b/internal/atlas/image_test.go
index 5798d7515..d27220f99 100644
--- a/internal/atlas/image_test.go
+++ b/internal/atlas/image_test.go
@@ -125,8 +125,8 @@ func TestEnsureIsolated(t *testing.T) {
 		t.Errorf("got: %v, want: %v", got, want)
 	}
 
-	pix, err := img4.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix = make([]byte, 4*size*size)
+	if err := img4.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < size; j++ {
@@ -217,8 +217,8 @@ func TestReputOnAtlas(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	pix, err := img1.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix = make([]byte, 4*size*size)
+	if err := img1.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < size; j++ {
@@ -241,8 +241,8 @@ func TestReputOnAtlas(t *testing.T) {
 		t.Errorf("got: %v, want: %v", got, want)
 	}
 
-	pix, err = img1.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix = make([]byte, 4*size*size)
+	if err := img1.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < size; j++ {
@@ -329,8 +329,8 @@ func TestExtend(t *testing.T) {
 	// Ensure to allocate
 	img1.ReplacePixels(p1, 0, 0, w1, h1)
 
-	pix0, err := img0.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix0 := make([]byte, 4*w0*h0)
+	if err := img0.ReadPixels(ui.GraphicsDriverForTesting(), pix0); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < h0; j++ {
@@ -348,8 +348,8 @@ func TestExtend(t *testing.T) {
 		}
 	}
 
-	pix1, err := img1.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix1 := make([]byte, 4*w1*h1)
+	if err := img1.ReadPixels(ui.GraphicsDriverForTesting(), pix1); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < h1; j++ {
@@ -395,8 +395,8 @@ func TestReplacePixelsAfterDrawTriangles(t *testing.T) {
 	dst.DrawTriangles([graphics.ShaderImageCount]*atlas.Image{src}, vs, is, affine.ColorMIdentity{}, graphicsdriver.CompositeModeCopy, graphicsdriver.FilterNearest, graphicsdriver.AddressUnsafe, dr, graphicsdriver.Region{}, [graphics.ShaderImageCount - 1][2]float32{}, nil, nil, false)
 	dst.ReplacePixels(pix, 0, 0, w, h)
 
-	pix, err := dst.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix = make([]byte, 4*w*h)
+	if err := dst.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < h; j++ {
@@ -442,8 +442,8 @@ func TestSmallImages(t *testing.T) {
 	}
 	dst.DrawTriangles([graphics.ShaderImageCount]*atlas.Image{src}, vs, is, affine.ColorMIdentity{}, graphicsdriver.CompositeModeSourceOver, graphicsdriver.FilterNearest, graphicsdriver.AddressUnsafe, dr, graphicsdriver.Region{}, [graphics.ShaderImageCount - 1][2]float32{}, nil, nil, false)
 
-	pix, err := dst.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix = make([]byte, 4*w*h)
+	if err := dst.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < h; j++ {
@@ -490,8 +490,8 @@ func TestLongImages(t *testing.T) {
 	}
 	dst.DrawTriangles([graphics.ShaderImageCount]*atlas.Image{src}, vs, is, affine.ColorMIdentity{}, graphicsdriver.CompositeModeSourceOver, graphicsdriver.FilterNearest, graphicsdriver.AddressUnsafe, dr, graphicsdriver.Region{}, [graphics.ShaderImageCount - 1][2]float32{}, nil, nil, false)
 
-	pix, err := dst.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix = make([]byte, 4*dstW*dstH)
+	if err := dst.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 		t.Fatal(err)
 	}
 	for j := 0; j < h; j++ {
@@ -717,8 +717,8 @@ func TestImageReplacePixelsModify(t *testing.T) {
 		}
 
 		// Check the pixels are the original ones.
-		pix, err := img.Pixels(ui.GraphicsDriverForTesting())
-		if err != nil {
+		pix = make([]byte, 4*size*size)
+		if err := img.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 			t.Fatal(err)
 		}
 		for j := 0; j < size; j++ {
diff --git a/internal/atlas/shader_test.go b/internal/atlas/shader_test.go
index 87d3676c9..ed7a954fd 100644
--- a/internal/atlas/shader_test.go
+++ b/internal/atlas/shader_test.go
@@ -48,8 +48,8 @@ func TestShaderFillTwice(t *testing.T) {
 	s1 := atlas.NewShader(etesting.ShaderProgramFill(0x80, 0x80, 0x80, 0xff))
 	dst.DrawTriangles([graphics.ShaderImageCount]*atlas.Image{}, vs, is, affine.ColorMIdentity{}, graphicsdriver.CompositeModeCopy, graphicsdriver.FilterNearest, graphicsdriver.AddressUnsafe, dr, graphicsdriver.Region{}, [graphics.ShaderImageCount - 1][2]float32{}, s1, nil, false)
 
-	pix, err := dst.Pixels(g)
-	if err != nil {
+	pix := make([]byte, 4*w*h)
+	if err := dst.ReadPixels(g, pix); err != nil {
 		t.Error(err)
 	}
 	if got, want := (color.RGBA{pix[0], pix[1], pix[2], pix[3]}), (color.RGBA{0x80, 0x80, 0x80, 0xff}); got != want {
@@ -80,8 +80,8 @@ func TestImageDrawTwice(t *testing.T) {
 	vs = quadVertices(w, h, 0, 0, 1)
 	dst.DrawTriangles([graphics.ShaderImageCount]*atlas.Image{src1}, vs, is, affine.ColorMIdentity{}, graphicsdriver.CompositeModeCopy, graphicsdriver.FilterNearest, graphicsdriver.AddressUnsafe, dr, graphicsdriver.Region{}, [graphics.ShaderImageCount - 1][2]float32{}, nil, nil, false)
 
-	pix, err := dst.Pixels(ui.GraphicsDriverForTesting())
-	if err != nil {
+	pix := make([]byte, 4*w*h)
+	if err := dst.ReadPixels(ui.GraphicsDriverForTesting(), pix); err != nil {
 		t.Error(err)
 	}
 	if got, want := (color.RGBA{pix[0], pix[1], pix[2], pix[3]}), (color.RGBA{0x80, 0x80, 0x80, 0xff}); got != want {
diff --git a/internal/buffered/image.go b/internal/buffered/image.go
index 75b4fefd7..740f485d5 100644
--- a/internal/buffered/image.go
+++ b/internal/buffered/image.go
@@ -80,20 +80,20 @@ func (i *Image) MarkDisposed() {
 	i.img.MarkDisposed()
 }
 
-func (img *Image) At(graphicsDriver graphicsdriver.Graphics, x, y int) (r, g, b, a byte, err error) {
+func (i *Image) At(graphicsDriver graphicsdriver.Graphics, x, y int) (r, g, b, a byte, err error) {
 	checkDelayedCommandsFlushed("At")
 
-	idx := (y*img.width + x)
-	if img.pixels != nil {
-		return img.pixels[4*idx], img.pixels[4*idx+1], img.pixels[4*idx+2], img.pixels[4*idx+3], nil
+	idx := (y*i.width + x)
+	if i.pixels != nil {
+		return i.pixels[4*idx], i.pixels[4*idx+1], i.pixels[4*idx+2], i.pixels[4*idx+3], nil
 	}
 
-	pix, err := img.img.Pixels(graphicsDriver)
-	if err != nil {
+	pix := make([]byte, 4*i.width*i.height)
+	if err := i.img.ReadPixels(graphicsDriver, pix); err != nil {
 		return 0, 0, 0, 0, err
 	}
-	img.pixels = pix
-	return img.pixels[4*idx], img.pixels[4*idx+1], img.pixels[4*idx+2], img.pixels[4*idx+3], nil
+	i.pixels = pix
+	return i.pixels[4*idx], i.pixels[4*idx+1], i.pixels[4*idx+2], i.pixels[4*idx+3], nil
 }
 
 func (i *Image) DumpScreenshot(graphicsDriver graphicsdriver.Graphics, name string, blackbg bool) error {