SEARCHING YOUR COMPUTER
PART 4: DUPLICATE IMAGE FILES

©2021 Donald R. Snow - Last updated 2021-02-28
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ABSTRACT: This is Part 4 of a 4-part series about searching for files on your computer and discusses finding duplicate image files which includes photos from digital cameras and scanned.  Image files may be exactly the same or very similar and can be the same picture, but different formats, e.g. jpg vs tif.  We will discuss programs to find these similar files and even give you the percent that they are similar.  They show you both, so you can delete one or keep both.  Image files take up lots of space on your hard drive(s), so duplicates need to be cleaned up.  The notes for this class and related articles, all with active internet links, are on Don's webpage https://uvtagg.org/classes/dons/dons-classes.html .

    WELCOME AND INTRODUCTION

  1. Instructor is Donald R. Snow ( snowd@math.byu.edu ) of Provo and St. George, Utah.
  2. These notes, with active internet links and other related articles, are on Don's website  https://uvtagg.org/classes/dons/dons-classes.html .
  3. Tips:  (1)  Easy to put an icon on your desktop for these notes or any other webpage; just drag the icon from in front of the address in your browser to your desktop.  (2)  To open a link from here in another tab, but keep your place in these notes, hold down the Control key while clicking the link.
  4. The problem for today:  How to find similar or exactly the same image files, regardless of their names, so you can delete the duplicates.

    5. FILES ON OUR COMPUTERS

  5. Part 1 of this class series discussed finding files with specified words in the file names.  Part 2 dealt with finding files with specified text inside. Part 3 was about finding files with duplicate non-image content.
  6. This class, Part 4, deals with finding duplicate image files with the same or different names and same or different formats, e.g. jpg vs tif. 
  7. As before, consistent file-naming simplifies most file search tasks, so you can tell what's in the file without opening it; my file naming system was discussed in other classes  
  8. To be sure your computer shows the file extensions, e.g. .odt, docx, .txt, .jpg, .tif, etc., see the notes for Part 1 of this series.
  9. In Part 3 we discussed how to see the free space and what's taking up the space on your hard drive(s). Also, that you can purchase inexpensive external harddrives to store files you don't use very often.  

    10. DUPLICATE IMAGE FILES

  10. For image files with the same name the method using the program EVERYTHING that we discussed in Part 3 works well.
  11. For image files you usually need to see the images to know which to save or delete, so here we only discuss programs that show you the images 
  12. Digital cameras have a date and time stamp that, if set correctly, records in the metadata the exact date and time the photo was taken; if several people are together and have the date/time set correctly on their cameras, all the photos of an event will have the same time embedded in the metadata and they can be compared easily.
  13. The photo metadata can be viewed by right-clicking the file in File Explorer > Properties > Details; free programs will copy the date/time from the metadata into the photo name so the photos sort in chronological order; I use the free program NameEXIF to do this --  ttps://namexif.en.uptodown.com/windows/download  (Be careful not to download the bloatware they have there.); with this I can find photos I took on any day and time, even if I haven't fully renamed the files yet.  
  14. Awesome Photo Duplicate Finder -- https://www.duplicate-finder.com/photo.html ; finds dup photos and shows their percent similarity; click on title of percent column so they sort from 100% down to start examining them side-by-side from exactly the same on down; shows the resolution so you can keep the highest resolution image; can see the names of the files so they can also be compared; can delete one immediately, if you want; very helpful program and easy to use, but comparing takes time   
  15. Duplicate Cleaner Free -- https://www.digitalvolcano.co.uk/dcdownloads.html  -- discussed in Part 3; after searching for dup images, click on Image Preview to see images of the duplicate group; can mark which to delete or keep; but doesn't show the images side-by-side and not large to examine them; but works well and has good file selection options, in addition to comparing images   
  16. Find other free dup image programs and recommendations about them by Google searches for terms like [free duplicate image programs and recommendations]; but the two discussed here are good ones 

    17. CONCLUSIONS

  17. Archive the highest resolution image copy you have, since you can make lower resolution copies from it, but not go back to higher. 
  18. File maintenance takes time, but needs to be done.  Your kids will appreciate you cleaning up all the duplicates and labeling the files on your computer.
  19. This is the last class in this 4-part series about searching your computer.  Other class notes and articles on my website have additional info about this.
Return to the  Utah Valley Technology and Genealogy Group Home Page  or  Don's Class Listings Page .