There are a few standalones that let you get information on image files:
Get information about a variety of image file formats with the imginfo standalone.
Get information about a variety of image file formats, including mental ray formats like .map, with the imf_info standalone.
Get information about SOFTIMAGE picture files with the infopic standalone.
Highlight on a pixel-by-pixel basis the differing pixels between two input images with the diffpic or imf_diff standalones.
Getting Image File Information
The imginfo standalone can display information about a number of image formats.
The imginfo standalone automatically detects supported image file formats, so input files do not require an extension (such as .pic) to identify their format. However, if the file on disk has an extension, you should specify it.
The imginfo standalone can display information for any file format for which their is a dynamic shared object (DSO on Linux systems) or a dynamic link library (DLL on Windows systems).
The Setup program installs these DSOs or DLLs to <install directory>/Application/bin/sil. When you type imginfo, the usage message lists the supported file formats.
To run imginfo, you must set the environment variable SI_IMAGE_PATH to point to the <install directory>/Application/bin/sil directory.
Getting Other Image File Information
The imf_info standalone displays information about all specified images, in a spreadsheet-like layout. Information includes the image width and height, number of color components, bit depth, gamma, line ordering, image type, and image format.
Activating the -p option displays additional image information including average brightness and rgb values of image pixels, as well as a multi-line histogram of color information. Each line of the histogram represents a sub-range of the luminance values between 0.00 and 1.00.
For example, the first line represents values from 0.00 to 0.0625 while the last line represents values from 0.9375 to 1.00. The numeric value in each line is the percentage of image pixels whose luminance values are within that sub-range, while the r's, g's, and b's indicate the distribution of color components among those pixels.
The imf_info standalone automatically detects supported image file formats, including mental images formats like .map, so input files do not require an extension (such as .pic) to identify their format. However, if the file on disk does have an extension, you must specify it.
Where <image file> is the name of an image file, including the file extension. To get information about multiple images, specify their names one after the other and separated by a space.
Getting Picture File Information
The infopic standalone displays information about SOFTIMAGE picture files.
For each subregion, the following information is displayed:
Number of bits, data type, and compression method for the RGB channels
Number of bits, data type, and compression method for the alpha channel
The infopic standalone is useful for finding the pixel ratio and to determine whether a picture is too big to display on the monitor. It is also useful for determining whether a picture corresponds to the correct format for video transfers.
The diffpic standalone displays an image whose pixels are highlighted when the corresponding pixels of the two input pictures are different.
If you use the -i option, the intensity of each displayed image pixel is equal to the difference of the intensity of the corresponding pixels of the two input pictures.
diffpic <picture 1> <picture 2> [-o <output filename>] [-i] [-a] [-d] [-r <repeat count>] [-s <start frame> <end frame> <step>] [-v]
Where <picture 1> is the name of the first picture and <picture 2> is the name of the second picture.
Comparing Images with imf_diff
The imf_diff standalone compares two image files. The files are compared, and a comparison summary is printed. If an output image (outimage) is specified, a difference image with a histogram is written to the output image. The file format of this file is specified with the output file type (outtype) if present, or taken from the file name extension if not.
Where image1 is the name of the first picture file and image2 is the name of the second picture file.
The most common options are -d -f -u.
Note that the sampling nature of mental ray means that the true image is approximated with appropriately selected samples until the desired image quality criteria are satisfied. This approach ensures consistent quality, but it does not necessarily create images that are bit-for-bit identical if rendered under different circumstances, such as different image task sizes, image task assignments to threads or machines, different machines or different networks, or different sampling options. Typically, differences shown in blue in the color histogram are irrelevant.