How useful is PNG?


#1

PNG is starting to be used more often now, but I’m still sitting with GIF and JPG. I understand that PNG is a GIF-replacement that doesn’t have questionable licensing issues, and it has better transparency options. It’s not good for photos (JPG) but very good for icons etc. (GIF). Am I right so far?

I don’t have any image editing that can work with it. Windows XP doesn’t, and neither does my aging PaintShopPro. What would be a good tool?

Most importantly though: Which browsers support PNG? Okay, if the user downloads the right plugin then any browser can be made to support it, but off the shelf, some users might be shut out. I want to deliver content to my mom too, and I don’t expect users to be on the cutting edge just because developers are.

Any comments you can share on this?


TorbenGB


#2

.png is pretty cool, but you hit the nail on the head… I won’t use them in a mainstream public site until there is more browser implementation.

I DO use the .png format for most of my graphical development… I just have to export my work to another format before I put it up on the web.

You said that .png isn’t very good for photos. That’s true on a file size basis, but picture quality is very high. I’ve visited sites that have all their graphical elements done in .png… it’s the same types of sites that expect you to have broadband for all the Flash and Shockwave… dial-up need not apply.

A site that tries to keep the status of browsers and .png is here. I think it’s about a year out of date but it does give a good and pretty complete overview.


#3

Paint Shop Pro v7 supports PNG quite well. Oh, and Windows XP is an operating system, not an application. The “Windows Picture and Fax Viewer” that comes with it displays PNG. I wouldn’t consider MS Paint or Picture It! to be a serious image editor.

Internet Explorer 6.0 will display PNG with one cavaet - it does not composite PNGs that have alpha transparency when rendering the web page. You can however add a background color to the PNG that matches the background color of the web page to help compensate for this implementation bug, or use a behavior that converts image elements with PNGs to the propietary method that MS dreamed up of supporting alpha transparency using DirectX and CSS filters.

Other than that, PNG support in IE 6 is good enough that you can convert non-animated gifs to PNG today and save on bandwidth. I’ve already switched to PNG because most visitors to my site are using IE 6.

:cool: Perl / MySQL / HTML+CSS


#4

Thanks for your feedback.
Since only about half of my visitors use MSIE6, and most of the rest use MSIE5 (Mozilla and others are <10%), many users wouldn’t be able to see the images at all. I’d hate having to code workarounds just to have properly transparent PNG in MSIE. I guess I’ll just keep going with the GIF/JPG combo.
(I am aware that Windows isn’t an application.)


TorbenGB


#5

Thanks for your feedback.

This incorrect. PNG supports images using a 256 color indexed palette, with a single transparent color, just like the GIF format. This works fine in Internet Explorer 5+ if you use a simple tool like gif2png or Image Magick to convert existing GIF files. You can do this today and the resulting PNG files will be smaller than the original GIF ones.

The JavaScript or CSS code workarounds are only necessary if you wish to use PNG with 24-bit color and an alpha channel. The only workaround you may want to do only affects the PNG files and that involves removing the gamma chunk, as Internet Explorer does not do gamma adjustment correctly. Removing the gamma chunk would only have adverse effects if you were specificying a gamma value for the rest of the web page elements already. Gamma chunks are usually added by applications like Photoshop and Paint Shop Pro, which allow the user to calibrate the display gamma.

:cool: Perl / MySQL / HTML+CSS