ImageMan provides "Option Block Functions", such as ImgXOptBlkAdd, ImgXOptBlkGet, ImgOptionNames, ImgOptionValue, to allow you to more accurately determine the characteristics of an existing image, or precisely define image characteristics as you define them.
How does it help me?
Frequently, we run into images that have a non-standard filetype (ie a tiff image name 'Myown.001", and wish to determine what type of image it is. This would be available using the "EXTENSION" attribute of the ImageAttributes object. Similarly, one may wish to know what compression was used in originally saving that tiff image. The "TIFF_COMPRESS" attribute makes this readily available.
Defining ImageAttributes When Saving Images
If save images without defining Image Attributes, ImageMan will save the default values of the image format being saved. For example, in a file saved with .tif, the "EXTENSION" would be "TIF" and "TIFF_COMPRESS" would default to "NONE" for b/w images, or "PACKBITS" for color images. NOTE: This will be the case, for certain attributes in any format, whether the image saved is a new Image, or resaving an existing image. See the ImageAttributes book to determine what attributes of your format that will require explicit writing of the attribute to retain the existing values.
General Image Attributes
There are a group of attributes that are not format specific. As a rule, this group may be found in any image format. The only attribute that is assured to be supported in all format written by Imageman is EXTENSION
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