Implementations must support all images formats that are supported in the underlying platform (for example, image-handling module). All implementations must support PNG (as mandated by MIDP specifications [MIDP1.0] and [MIDP2.0]), GIF (including animated GIFs), and JPEG (as mandated by the JTWI specification [JTWI]) formats). Animated GIFs must be supported if used through high-level APIs, that is, images in Form, List, and Alert. When animated GIF is used through a high-level API, the implementation will automatically present the animation.
Images must be supported in a high-level API, that is, in List, Alert, and Form (ChoiceGroups, ImageItems). Implementations can choose whether the layout is dynamic based on image size or based on normal icon sizes for a given user interface style.
Transparency support must be implemented as stated in MIDP 2.0 specifications. Based on image format capabilities, both simple palette transparency (for example, TRNs chunk of PNG) and alpha-channel-based transparency must be supported.
Image transparency must be supported throughout the lcdui APIs (both high level and low level). For example, List elements in particular may have images with transparency information.
Also, transparency must be supported when presenting images defined in MIDlet-n and MIDlet-icon attributes in JAD or manifest files. PNG is the only format that is supported in MIDlet-icon and MIDlet-n attributes.
No hard-coded limitations must exist on supported image sizes. Many applications tend to use images that may be significantly larger than the size of a screen.