| <!DOCTYPE html> |
| JPEG image RGB pixels should render without color corruption and in strict<br> |
| order, regardless of the underlying machine pixel buffer endianess.<br><br> |
| |
| <img src="resources/rgb-jpeg-red.jpg" onload="test(this, [255,0,0,255])"> |
| <img src="resources/rgb-jpeg-green.jpg" onload="test(this, [0,255,0,255])"> |
| <img src="resources/rgb-jpeg-blue.jpg" onload="test(this, [0,0,255,255])"> |
| |
| <pre id="log">PASS</pre> |
| |
| <script> |
| if (window.testRunner) { |
| window.testRunner.waitUntilDone(); |
| window.testRunner.dumpAsText(); |
| } |
| |
| function log(message) |
| { |
| document.getElementById("log").textContent += '\n' + message; |
| } |
| |
| function averagePixelComponents(data, size) |
| { |
| var r = 0, g = 0, b = 0, a = 0; |
| for (var i = 0, total = size * 4; i < total; i += 4) { |
| r += data[i + 0]; |
| g += data[i + 1]; |
| b += data[i + 2]; |
| a += data[i + 3]; |
| } |
| |
| return [r / size, g / size, b / size, a / size]; |
| } |
| |
| function averagePixelShouldBe(pixel, expect, tolerance) |
| { |
| var delta = 0; |
| pixel.forEach(function(component, i) { |
| delta = Math.max(Math.abs(pixel[i] - expect[i]), delta); |
| }); |
| |
| if (delta > tolerance) |
| log('FAIL: [' + pixel + '] expected [' + expect + '] +/- ' + tolerance); |
| } |
| |
| function testImage(image, expect) |
| { |
| // Create a canvas, load the given image in it. |
| var canvas = document.createElement("canvas"); |
| canvas.width = canvas.height = 64; |
| var context = canvas.getContext("2d"); |
| context.drawImage(image, 0, 0); |
| |
| // Compare the canvas pixel component averages. |
| var pixels = context.getImageData(0, 0, 64, 64).data; |
| var result = averagePixelComponents(pixels, 64 * 64); |
| |
| var pixelTolerance = 3; |
| averagePixelShouldBe(result, expect, pixelTolerance); |
| } |
| |
| function test(image, expect) |
| { |
| try { |
| loadedImages = window.loadedImages || 0; |
| testImage(image, expect); |
| if (++loadedImages < 3) |
| return; |
| } catch (e) { |
| log('FAIL: ' + e.message); |
| } |
| |
| if (window.testRunner) |
| window.testRunner.notifyDone(); |
| } |
| </script> |
