Hi, I've been posting lots of strategy game screenshots in game websites (via Photobucket and Imageshack) for the past few years in JPG format, but recently I switched to PNG format because its much better definition.
But PNG pics seem to display much slower, or am I imagining it?
Is there any way round it, or shall I switch back to JPG?
Thanks

Nope, you're not imagining it. PNG images have much larger file sizes than the same images with the same dimensions in JPG format. The reason for that, and for the better definition, is that they have lossless compression, which JPGs don't. Other common lossless formats are TIFF and BMP, but those are rarely suitable for display purposes.

Okay thanks, I'm just a wargame-playing grunt and all this tech stuff is beyond me, but are you saying i've got no choice but to go back to Stone Age JPG?
To clarify, JPG is fine UNTIL I need to draw stuff on it with Paint program (such as thrust-line arrows etc), which display with blurry runny colours, and I do a LOT of drawing..
For example this top test screenshot is JPG, see how bad the two arrows look, yet they're fine in the PNG shot below it.

No, there's no reason for you to go back to the JPG format unless you get complaints from others about how slowly the PNG images load. For example, I'm on dialup and still waiting for all the icons and images on this page to load because of the large sizes of both files. I don't actually need to see your pix to know what you're talking about, though.

The problem with ongoing changes to JPGs is that when you modify the same JPG over and over, it loses quality each time you save it. I suspect that's what you're seeing in your sample. Although it might be a bit of a pain for you, here's what I suggest as a workaround:

Keep a copy of your original PNG image. Every time you want to make changes, save that image as a PNG with a different name. Also save a copy as a JPG, which is the one to upload.

Then, for the next edit, reload that extra PNG, make changes, and save again as a PNG and a JPG, and so on.

That way, you'll lose only a small amount of quality in each JPG. Does that make sense to you?

Another way to deal with the problem is to use a free graphics editor like Irfanview or the GIMP, both of which have layers capability. (At least I think IV does.) Using the layers feature will allow you to save an image as a PNG with each set of changes on a different layer. You can then export/save it as a JPG, with the same results I mentioned above. Of course there's a learning curve involved with both programs, so if you want to stick with the simpler Paint program, it should still work for you.

Hope this helps!

Thanks for the ways to overcome it guys, but as a fallback plan I might upgrade to a faster connection speed anyway because its cheaper than my current 2Mb speed package, (if I understand the AOL adviser properly) as english wasn't his first language..
He said - "I can offer you Broadband Wireless up to 8Mb with WiFi Router", but when I kept asking him to explain what 'wireless' and 'Wifi router' meant, he just kept saying stuff like "it depends on your requirements" without giving me straight answers, so I hung up, and he'll rate a big fat 'zero' on my next AOL feedback form..;)
Anybody here at Bleeping care to tell me about wireless and Wifi routers, like what are they?
Thanks

Upgrading might make your uploading the picture/graphic much faster, but will not change the download speed of others, which seems to be the main problem using other than .jpegs. To be honest, I would myself much prefer a graphic to appear/load faster than wait for a prettier one with nice arrows. In your example, the first loaded much faster, and provided the information I would want to know.
Regards,
John

Okay guys thanks, but can I just ask a question I should have perhaps asked earlier -
Below are the (default?) options screens which come up when I select 'Save as PNG' (left), and 'Save as JPG or GIF' (right), so can you tell me which boxes I should or shouldn't tick, and whether I should adjust the numerical value input and slider bars?
I've never touched anything for a very long time, but maybe I should tweak something?
(To recap, all I do is capture game screenshots, save them and upload to Photobucket, from where I post them into game forums)

I take it you are using IrfanView from the screenshots.If so I can only address the right hand drop down.
Generally, I leave the checked boxes alone, and only use the slider bar if I am dealing with a very large (e.g.456Kb) picture after cropping; in this case a 10 to 15 percent reduction, using the slider bar, will not result in much loss of detail at all. I would suspect that the ofiginal screenshots are somewhat less than that, and if so, I would simply crop them and keep the "save quality" bar at "good." This especially so since you are concerned with fuzzy arrows; reducing the quality may easily make them MORE fuzzy---try it yourself to see if it makes any difference (save the tests AS another name so you don't overwrite the original, and compare the quality of the important parts of the picture that get your meaning/instruction across.
Cheers,
John