У вас же есть установленный Oziexplorer на компе? Нажимаем F1, выбираем самый последний раздел OziExplorerCE и читаем там OziExplorerCE Help. Глава Image Formats Supported. Там всё написано.
Цитата:

OziExplorerCE only supports the image formats ozfx3, ozf2 and ecw. Ozfx3 and ozf2 were especially developed for use in OziExplorerCE.

A conversion program is provided to convert map images into ozfx3 format. Most of the file formats supported by PC OziExplorer can be converted.

(Note: Because the code libraries available only suit the ARM cpu the ECW support is only available for PDA's with ARM cpu's.)

The ECW format is highly compressed and therefore it takes longer to uncompress the piece of image required and this makes it slower to use than the ozfx3 format.

The OZF2 format has been superseded by the OZFx3 format and can no longer be created by the Img2ozf conversion software.

Why a New Format?

The PocketPC and CE devices with limited RAM require an image format which can be read from disk as required, that is, just the portion needed to be displayed on the screen can be read from the file (this is called paging), this keeps the memory requirements of the software very low. The OZFx3 format was developed to allow very fast paging from disk. ECW is also a paging format but due to its high compression, the ECW format is a slower format to load on a PDA than OZFx3.

As an example:

the BMP format cannot be "paged" from disk (generally) so the entire image must be read and stored in memory. This means 2 copies of the image are needed when the image is loaded, 1 on file and 1 in memory. CE devices usually do not have enough memory to allow this for reasonable sized maps. This also applies to GIF, JPG, PNG and most others.
In some cases the size of the image stored on a plug in memory card may exceed the device's program memory, because the ozfx3 format is paged from disk the software can still load and use the large image.

There is no upper limit on the size of an ozfx3 image file, the limit is the ability to convert the image

OZF Conversion Software

A program to convert image files to the ozfx3 format (img2ozf.exe) is available from the OziExplorer website (includes additional Help on using the Img2ozf program).

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