About Microsoft Document Imaging Format (MDI)
Microsoft Office Document Imaging uses Microsoft Document Imaging Format (MDI), a file format based on the Tagged Image File Format (TIFF) that is designed to store images by page layout. In Office Document Imaging, you can open and save files in the MDI format as well as the Tagged Image File Format (TIFF) format. Both formats are capable of storing text recognized by optical character recognition (OCR) along with images.
File format comparison
While you can open and edit TIFF files created with Office Document Imaging by using many other graphics applications, MDI files can only be opened or edited in Office Document Imaging. If you are going to share files with people who are using Office Document Imaging 2002, or another document imaging program, save your files in TIFF format for compatibility.
MDI files have the following advantages over TIFF files:
- Reduced file size Images that are saved in the MDI file format take up less disk space than the same images saved in the TIFF format.
- Improved image fidelity Images saved in the MDI file format are generally higher fidelity (or quality) than the same images saved in the TIFF (with the Perform lossless compression (LZW). option selected) format.
File format selection
There are different times within Office Document Imaging when you can choose the file format (either MDI with an .mdi extension or TIFF with a .tif extension) for your document:
Scanning a document The scanning preset you choose determines the format the scanned document is saved in. You can create your own scanning preset or edit an existing preset to change the file format.
Saving a document You can select the file format in the Save as type list in the Save As dialog box when you save a file.
Importing a document The File Import preferences button on the Other tab in the Options dialog box (Tools menu) allows you to select the default file format for documents that you import from other programs.
Office Document Imaging creates MDI files in these formats:
- Monochrome One bit per pixel, MODI BW compression
- Grayscale 8 bits per pixel, MODI Color compression
- Color 24 bits RGB, MODI Color compression
Office Document Imaging supports:
- All compression types listed in the TIFF 6.0 specification.
- Different compression types for each page of a multi-page document.
- TIFF images with 1-bit, 4-bit, 8-bit, or 24-bit color depth (both palette and non-palette).
- MDI images with 1-bit, 8-bit, or 24-bit color depth.
- RGB and CMYK color spaces.
- Tiled images.
Office Document Imaging does not support:
- YCbCr color space, except when the image is JPEG.
- CIE Lab color space.
- Images with more than five samples per pixel, or a sample size larger than 32 bits.
- Images in Planar format.