images

Expected Behavior

Running validator https://validator.w3.org on basic <picture> elements as per setup config should not result in errors.

Current Behavior

Currently when running validator on:

<picture class="lozad" style="display: block; min-height: 1rem" data-iesrc="images/thumbs/04.jpg" data-alt="">
    <source srcset="images/thumbs/04.jpg" media="(min-width: 1280px)">
   

SVG will very likely take a little longer to render than a base64-encoded raster image. And the Gaussian Blur applied to the simple SVG shapes created by Primitive is probably quite CPU intensive.

Let's run a series of performance tests, ideally on WPT, to compare LQIP raster image rendering performance vs. SQIP rendering performance and also compare CPU utilization.

The value of allowed undershoot in the resize mode ExactOrSmaller is currently a compile time constant. It would be great to make this configurable for the developer using the library:

https://github.com/facebookincubator/spectrum/blob/fa9e917f5b062797d51c3e013aaa7d61926c72a5/cpp/spectrum/core/ResizeUtil.h#L22-L27