CSS3 Animation Cause Poor Text Rendering

Question

I'm trying out a CSS3 animation on a background image. Everything's working well, the problem is that on Chrome the text ends up being blurred when the animation is in progress:

During Animation:

Turning off the animation:

As you can see the text rendering is fine when the animation is turned off, I know there's the usual issue with text rendering but I can't understand why the rendering is poor on Chrome when the animation is in progress. I'm not sure there's anything I can do about it really. I've tested the animation on Firefox and IE and it's ok. By the way I'm working on Windows.

Firefox:

IE:

EDIT

.bg-div {
    position: fixed;
    width: 110%;
    height: 110%;
    transform: translate(-5%, -5%);
    -moz-transform: translate(-5%, -5%) rotate(0.02deg); /* rotation to solve choppy animation on Firefox */
    -ms-transform: translate(-5%, -5%);
    background-image: url('images/colour-test.jpg');
    background-size: cover;
    -webkit-animation: bg-animation 10s linear infinite;
    -moz-animation: bg-animation 10s linear infinite;
    -ms-animation: bg-animation 10s linear infinite;
}

@-webkit-keyframes bg-animation {
    25% { transform: translate(-5.5%, -5.5%); }
    50% { transform: translate(-5.3%, -4.9%); }
    75% { transform: translate(-4.8%, -4.3%); }
}
@-moz-keyframes bg-animation {
    25% { -moz-transform: translate(-5.5%, -5.5%) rotate(0.02deg); }
    50% { -moz-transform: translate(-5.3%, -4.9%) rotate(0.02deg); }
    75% { -moz-transform: translate(-4.8%, -4.3%) rotate(0.02deg); }
}
@-ms-keyframes bg-animation {
    25% { -ms-transform: translate(-5.5%, -5.5%); }
    50% { -ms-transform: translate(-5.3%, -4.9%); }
    75% { -ms-transform: translate(-4.8%, -4.3%); }
}
.content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 50%;
    height: 65%;
    text-align: center;
}

After reading the question and answer posted in the comments I've tried to adding -webkit-font-smoothing: subpixel-antialiased; to .bg-div but that didn't make any difference.

EDIT 2

Okay so this is a bit of a weird one, during the animation apparently the position: fixed is making the text blurry. I don't know how that is possible, anyway once I removed the position: fixed and the background was animating the text was displayed correctly. It's still not what I want because I need the background to be fixed.

Answer 1

In my testing, the problem is fixed if the transform is not used on .content. Luckily, you don't need to use transform to position your content div.

Use this margin: auto trick to position instead

• Using this method, you do not need to use transform: translate(-50%, -50%)

• The content is centered with the combination of top, right, bottom, left, margin: auto and the percentage width and height.

.content {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  margin: auto;
  width: 50%;
  height: 65%;
  text-align: center;
}

Working Example

body { margin: 0 auto; width: 500px }

.bg-div {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  margin: auto;
  width: 800px;
  height: 800px;
  transform: translate(-5%, -5%);
  background: url('http://www.placehold.it/800') no-repeat;
  -webkit-animation: bg-animation 2s linear infinite;
  animation: bg-animation 2s linear infinite;
}
@-webkit-keyframes bg-animation {
  0% {
    transform: translate(-5.5%, -5.5%);
  }
  50% {
    transform: translate(-5%, -5%);
  }
  100% {
    transform: translate(-5.5%, -5.5%);
  }
}
@keyframes bg-animation {
  0% {
    transform: translate(-5.5%, -5.5%);
  }
  50% {
    transform: translate(-5%, -5%);
  }
  100% {
    transform: translate(-5.5%, -5.5%);
  }
}
.content {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  margin: auto;
  width: 50%;
  height: 65%;
  text-align: center;
}

<div class="bg-div"></div>

<div class="content">
  <h1>This looks better</h1>
  <input value="Text" />
</div>