| <!DOCTYPE html> |
| <title>PNG test: eXIf chunk</title> |
| <link rel="help" href="https://w3c.github.io/PNG-spec/#eXIf"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/html/canvas/resources/canvas-tests.js"></script> |
| <body> |
| |
| <h1>eXIf chunk</h1> |
| <p class="desc">test pixel values of a rotated PNG</p> |
| |
| <p class="output">Actual output:</p> |
| <canvas id="c" class="output" width="200" height="200"><p class="fallback">FAIL (fallback content)</p></canvas> |
| |
| <ul id="d"></ul> |
| <script> |
| var t = async_test("test pixel values of a rotated PNG"); |
| const img = new Image(); |
| img.onload = () => { |
| _addTest(function(canvas, ctx) { |
| ctx.drawImage(img, 0, 0); |
| |
| var pixel = ctx.getImageData(5, 5, 1, 1).data; |
| |
| // The image data stores a 100x100 red block above a 100x100 green block. |
| // By rotating the image, we can put the green block on top. |
| const pixel_expected = [0, 255, 0, 255]; |
| const epsilon = 2; |
| |
| _assertSame(pixel.length, pixel_expected.length, "pixel.length", "pixel_expected.length"); |
| assert_approx_equals(pixel[0], pixel_expected[0], epsilon); |
| assert_approx_equals(pixel[1], pixel_expected[1], epsilon); |
| assert_approx_equals(pixel[2], pixel_expected[2], epsilon); |
| assert_approx_equals(pixel[3], pixel_expected[3], epsilon); |
| }); |
| }; |
| img.src = "support/exif-orientation-bottom-right.png"; |
| </script> |
