exif-chunk.html (1402B)
1 <!DOCTYPE html> 2 <title>PNG test: eXIf chunk</title> 3 <link rel="help" href="https://w3c.github.io/PNG-spec/#eXIf"> 4 <script src="/resources/testharness.js"></script> 5 <script src="/resources/testharnessreport.js"></script> 6 <script src="/html/canvas/resources/canvas-tests.js"></script> 7 <body> 8 9 <h1>eXIf chunk</h1> 10 <p class="desc">test pixel values of a rotated PNG</p> 11 12 <p class="output">Actual output:</p> 13 <canvas id="c" class="output" width="200" height="200"><p class="fallback">FAIL (fallback content)</p></canvas> 14 15 <ul id="d"></ul> 16 <script> 17 var t = async_test("test pixel values of a rotated PNG"); 18 const img = new Image(); 19 img.onload = () => { 20 _addTest(function(canvas, ctx) { 21 ctx.drawImage(img, 0, 0); 22 23 var pixel = ctx.getImageData(5, 5, 1, 1).data; 24 25 // The image data stores a 100x100 red block above a 100x100 green block. 26 // By rotating the image, we can put the green block on top. 27 const pixel_expected = [0, 255, 0, 255]; 28 const epsilon = 2; 29 30 _assertSame(pixel.length, pixel_expected.length, "pixel.length", "pixel_expected.length"); 31 assert_approx_equals(pixel[0], pixel_expected[0], epsilon); 32 assert_approx_equals(pixel[1], pixel_expected[1], epsilon); 33 assert_approx_equals(pixel[2], pixel_expected[2], epsilon); 34 assert_approx_equals(pixel[3], pixel_expected[3], epsilon); 35 }); 36 }; 37 img.src = "support/exif-orientation-bottom-right.png"; 38 </script>