PNG vs JPG
-
I once heard that one of the advantages of PNG (over jpg eg.) is that when used on a webpage the image comes through in "blocks" making the site more responsive, while jpg had to be loaded in "one go". Did I dream this or is this really so? (I could only find things like transparancy, better for logo's etc... where jpg is better for real photos) thanks.
V.
(MQOTD rules and previous solutions) -
I once heard that one of the advantages of PNG (over jpg eg.) is that when used on a webpage the image comes through in "blocks" making the site more responsive, while jpg had to be loaded in "one go". Did I dream this or is this really so? (I could only find things like transparancy, better for logo's etc... where jpg is better for real photos) thanks.
V.
(MQOTD rules and previous solutions)I thought it was the other way round. You can use progressive jpg where the image starts blocky and is rendered in increasing detail as the rest arrives. PNG does have a rep for being better for 'geometric' stuff as opposed to photos. hth Cheers, Peter
Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012
-
I once heard that one of the advantages of PNG (over jpg eg.) is that when used on a webpage the image comes through in "blocks" making the site more responsive, while jpg had to be loaded in "one go". Did I dream this or is this really so? (I could only find things like transparancy, better for logo's etc... where jpg is better for real photos) thanks.
V.
(MQOTD rules and previous solutions)That's not quite right. You can have an interlaced JPG just as easily as you can have a progressive PNG. Where PNG has the advantage is if you save it as progressive. Progressive PNGs use a two dimensional interlace, which results in it doing 7 passes, instead of 4 passes - which means that you see something within 1/64 of the time you would see the whole item. It's worth being aware that no matter which option you choose, you would end up increasing the size of the none progressive/interlaced image.
-
I once heard that one of the advantages of PNG (over jpg eg.) is that when used on a webpage the image comes through in "blocks" making the site more responsive, while jpg had to be loaded in "one go". Did I dream this or is this really so? (I could only find things like transparancy, better for logo's etc... where jpg is better for real photos) thanks.
V.
(MQOTD rules and previous solutions)not quite true. progressive JPG (an uncommon but perfectly legal variation) allows for JPGs to be transferred in a series of images, each with higher resolution. the final image gets sharper as you go. interlaced PNG allows you to transfer pixels out of the standard order - they are transferred in a fixed pattern that's basically an ever-finer grid. the receiver would just the duplicate pixels it has received until all have been transferred. any speedup depends entirely on the reader being smart enough to display the images progressively.