interlacing

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 some sites that load a really low resolution image and then it gradually moves up to the full resolution photo. I would like my site to do the same but I don't know how to implement this. Does this requires multiple image files and more bandwidth? I would like it to use the same bandwidth/take the same amount of time as the traditional way does. For .JPG, save file as "Progressive JPEG" and that's it. Progressive .jpegs when

As a general rule of thumb when is it appropriate to make a gif interlaced, a png interlaced and a jpeg progressive? Especially when publishing the image on the web. JPEG: YES — use progressive scan . It makes files smaller ( each pass gets its own Huffman table ), and partial rendering looks quite good. GIF: NO — it's unlikely to make the file smaller, partial rendering is poor, and it's pointless for animGIFs. It's best not to use GIF at all ( yes, even for anims ). PNG: NO — it hurts compression (as data from each pass is statistically quite different). If the image is large, use high

I have a few images that were converted using Imagemagick and its interlaced operation. These were the animated GIF images. The issue is that, while converting, the images have distorted and I do not have original images with me as it was the previous developer who did the wonderful thing. The GIF is no more animating and each frame has 4 copies of the same frame with decreasing sizes. I have not worked much on Imagemagick before. Is there any way I can restore the original image from the distorted version? The command used was: convert <old-file.gif> -interlace plane <new-file.gif> Thanks