The Img Patch

The Img patch adds an alpha channel, better transparency support, and improved GIF support, including the ability to save GIF images. See the "Bitmaps and Images" section starting on page 625 for more information about these features. This patch also supports other image types (e.g., JPEG) that can be loaded as extensions; script-level support for other image types is typically provided through the Img extension, which can be used now without patching the Tcl core.