None are free, except the last one which is cool but only does one at
a time.
From best to good:
Image Comparer 3.3 MB (Shareware - $35)
"Scans your entire collection of images, analyzes their contents and
locates files that look alike."
http://www.bolidesoft.com/imagecomparer.html
ImageDupeless 3 MB (Shareware - $30)
"The program ImageDupeless is intended for search/find of the similar
images (duplicates) in the large collections. The supported graphic
file formats are JPEG, GIF, BMP, PCX, PNG, TIFF, PGM, WMF, EMF, EPS,
PSD, ICO. The comparison is based on the contents of images, not
depending on their sizes, formats, resolutions, etc. There are
advanced opportunities of cataloguing the galleries available on CDs
and of further off-line work with them."
http://www.imagedupeless.com/en/index.html
Image Compare 3.6 MB (Shareware - $10)
"A utility for finding and deleting duplicate image files."
http://www.epsoft.com.au/software/imagecom.html
Similar Image File Finder Software 758 KB (Shareware - $20)
"Compare pictures for pixel similarities. Choose which files to send
to the Recycle Bin."
http://www.sobolsoft.com/similarimage/
Image Compare Buddy 45 KB (Freeware)
"Automatically toggle between two images so changes can be easily
seen."
http://www.vsisystems.com/imagecompare.htm
*** NOTE ***
When launched, "Image Compare Buddy" displays a message window stating
that you must agree to have your home page and search page changed to
use the program. I have cracked it and uploaded it to MediaFire. When
you run the cracked version just click the YES button, nothing will
happen, except launch the program. I removed the command that launched
Internet Explorer after clicking the NO button, so clicking NO will
produce an error message.
http://www.mediafire.com/?jjzx3cmi993
ju.c