Function TestTransform_EXIF

transform_test.go:174–211

Test that each of the eight EXIF orientations is applied to the transformed image appropriately.

(t *testing.T)

// Test that each of the eight EXIF orientations is applied to the transformed
// image appropriately.
func TestTransform_EXIF(t *testing.T) {
	ref := newImage(2, 2, red, green, blue, yellow)

	// reference image encoded as TIF, with each of the 8 EXIF orientations
	// applied in reverse and the EXIF tag set. When orientation is
	// applied, each should display as the ref image.
	tests := []string{
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAAAQAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAGQAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nPrPwPAfDBn+////n+E/IAAA//9DzAj4AA==", // Orientation=1
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAAAgAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAGQAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nGL4z/D/PwPD////GcAUIAAA//9HyAj4AA==", // Orientation=2
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAAAwAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAFwAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nPr/n+E/AwOY/A9iAAIAAP//T8AI+AA=",     // Orientation=3
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAABAAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAGgAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nGJg+P///3+G//8ZGP6DICAAAP//S8QI+A==", // Orientation=4
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAABQAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAGAAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nPrPwABC/xn+M/wHkYAAAAD//0PMCPg=",     // Orientation=5
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAABgAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAGAAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nGL4z/D/PwgzMIDQf0AAAAD//0vECPg=",     // Orientation=6
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAABwAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAFgAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nPr/nwECGf7/BxGAAAAA//9PwAj4",         // Orientation=7
		"SUkqAAgAAAAOAAABAwABAAAAAgAAAAEBAwABAAAAAgAAAAIBAwAEAAAAtgAAAAMBAwABAAAACAAAAAYBAwABAAAAAgAAABEBBAABAAAAzgAAABIBAwABAAAACAAAABUBAwABAAAABAAAABYBAwABAAAAAgAAABcBBAABAAAAFQAAABoBBQABAAAAvgAAABsBBQABAAAAxgAAACgBAwABAAAAAgAAAFIBAwABAAAAAgAAAAAAAAAIAAgACAAIAEgAAAABAAAASAAAAAEAAAB4nGJg+P//P4QAQ0AAAAD//0fICPgA",         // Orientation=8
	}

	for _, src := range tests {
		in, err := base64.StdEncoding.DecodeString(src)
		if err != nil {
			t.Errorf("error decoding source: %v", err)
		}
		out, err := Transform(in, Options{Height: -1, Width: -1, Format: "tiff"})
		if err != nil {
			t.Errorf("Transform(%q) returned error: %v", src, err)
		}
		d, _, err := image.Decode(bytes.NewReader(out))
		if err != nil {
			t.Errorf("error decoding transformed image: %v", err)
		}

		// construct new image with same colors as decoded image for easy comparison
		got := newImage(2, 2, d.At(0, 0), d.At(1, 0), d.At(0, 1), d.At(1, 1))
		if want := ref; !reflect.DeepEqual(got, want) {
			t.Errorf("Transform(%v) returned image %#v, want %#v", src, got, want)
		}
	}
}

// Test that EXIF orientation and any additional transforms don't conflict.
// This is tested with orientation=7, which involves both a rotation and a