I am creating a site that uses an image as the background. I hate having the image load from top to bottom as it just makes the page look bad as it is loading. I have seen som
For .JPG, save file as "Progressive JPEG" and that's it. Progressive .jpegs when downloading, show at full size but blurry until fully downloaded.
Almost every picture viewer can save jpg as progressive. I recommend IrfanView because of simplicity, powerful batch, freeware...