Thread: .png Images in LGK

Web browser support for PNG
Main article: Web browser image format support

PNG support first appeared in Internet Explorer 4.0b1 and in Netscape 4.04.[23]

Despite calls by the Free Software Foundation[24] and the World Wide Web Consortium (W3C),[25] tools such as gif2png,[26] and campaigns such as burn all gifs,[27] PNG adoption on websites has been fairly slow.[citation needed]

GIF is found to be in use more than PNG for a few reasons:

* No support on old browsers (such as Internet Explorer below version 4).
* No animation, still images only (unlike GIF, though Mozilla's unofficial APNG format is a potential solution).

PNG compatible browsers include: Apple Safari, Google Chrome, Mozilla Firefox, Opera, Camino, Internet Explorer 7 (still numerous issues),[28] Internet Explorer 8 (improved) and many others. For the complete comparison, see Comparison of web browsers (Image format support).

However, Internet Explorer (Windows), has numerous problems which prevent it from correctly rendering PNG images.[28]

* 4.0 crashes on large PNG chunks.[29]
* 4.0 does not include the functionality to view .png files,[30] but there is a registry fix.[28]
* 5.0 and 5.01 have broken OBJECT support.[31]
* 5.01 prints palette images with black (or dark gray) backgrounds under Windows 98, sometimes with radically altered colors.[32]
* 6.0 fails to display PNG images of 4097 or 4098 bytes in size.[33][34]
* 6.0 cannot open a PNG file that contains one or more zero-length IDAT chunks. This issue was first fixed in security update 947864 (MS08-024). For more information, see this article in the Microsoft Knowledge Base: 947864 MS08-024: Cumulative Security Update for Internet Explorer [35]
* 6.0 sometimes completely loses ability to display PNGs, but there are various fixes.[33]
* 6.0 and below has broken alpha-channel transparency support (will display the default background color instead).[36][37][38] However there are various fixes:
o Degradable PNG Transparency for IE6
o webfx - PNG Behavior (IE behavior/.htc)
o The PNG problem in Windows Internet Explorer (IE behavior/.htc) (unmaintained)
o TwinHelix - Near-native PNG support with alpha opacity to IE 5.5 and 6 (IE behavior/.htc)
o A Better IE 5.5 and 6 PNG Fix (supports CSS background-position, background-repeat) (IE behavior/.htc)
o 24ways.org - Transparent PNGs in Internet Explorer 6 by Drew McLellan (Javascript)
o PNG-24 Alpha Transparency With Microsoft Internet Explorer or better (MSIE 5.5+) (PHP)
o PNGPong, an open source solution to display transparent PNGs in IE, Firefox, and Safari without the use of filters, PHP, or complicated Javascript and CSS (JavaScript+Flash)
o Cross Browser PNG Transparency (CSS)
o CSS PNG fix (with background call none fix) (CSS)
o SitePoint - Use 8-bit PNGs with Fireworks
o Use 8-bit PNGs with Photoshop and pngquant
o dillerdesign belatedPNG (JavaScript+VML)
o Dean Edwards’s IE7.js and IE8.js fixes this issue (for specially-named .PNG files, for performance reasons), and other IE 5.5, 6, and 7 CSS incompatibilities as well.
* 7.0 and below cannot combine 8-bit alpha transparency AND element opacity (CSS - filter: Alpha(opacity=xx)) without filling partially transparent sections with black.[39]
* All versions prior to 9.0 have inconsistent/broken gamma support.[28]
* No versions prior to 9.0 have color-correction support.[28]


Hope this helps.