Cisdem Duplicate Finder for Windows Advanced Guide

01 A removal rule that you need to know

As you may know, Cisdem Duplicate Finder is able to scan and auto mark duplicate files for deletion. However, what if you don’t want to follow the default rule --- you may want to remove files from a specific folder only, or you just want to keep files in a certain folder untouched? The good news is, Cisdem Duplicate Finder supports both scenarios. In this guide, we will show you how to take advantage of the priority rule to remove duplicate files.
 

1. Where can I set the priority rule?

Click the gear button to get into the Preferences window, navigate to Duplicate Files tab, you will be able to change the removal rule option to “Select duplicates for removal from prioritized location”.
 

2. How to set the priority rule?

Click the “Add” button to add the specific folders, and then enter the value of each folders.
 

3. What do the different values mean?

The value of the folders that are not added into the list is 0, the larger the value, the higher priority to delete. If you never want to delete the duplicates from a folder, you can set the value as -1. What's more, if you only want to delete the duplicates from a path, you can just add this one path into the list and set the value as 1.
 

User Story 1

“I would like to scan multiple folders on my hard drive, but only mark duplicate photos in only one folder for deletion, leaving the remaining folders unchanged. ”
 

The above request comes from a Cisdem user, and if you are facing the same problem, you can just add the specific folder into the priority list and set the value as 1.

User Story 2

“I look for the other option to delete from all other locations but not from a specific folder, is this option available ?”
 

The above question was asked by another Cisdem User, if you have the same question, you can just add the specific folder into the priority list and set the value as -1.

Conclusion

If you have personal preferences while marking duplicates with Cisdem Duplicate Finder for Windows, like marking duplicates from one folder priority, keeping one folder untouched or setting different marking priority for several folders, you can try the Priority removal rule. Should you have any more questions, please feel free to contact our support team at support@cisdem.com
 

02 Understanding Technical Definition of Duplicate Music/Video

Some users may have questions for scanning duplicate musics or videos with Cisdem Duplicate Finder, as reflected in some emails we’ve received below:
 

“I had multiple duplicates of songs but this only removed one duplicate, can Cisdem Duplicate Finder detect duplicate songs?”

“I'm scanning a massive iTunes collection as I'm a mobile entertainer, and have over 100,000 tracks, but it's only coming up with like a dozen duplicates when I know I have thousands. Why?”
 

In this article, let’s explore why this happens.

What does a music/video file composed of?

A computer file is fundamentally a sequence of bytes. These bytes represent the digital information that encodes the audio data, including the waveform, instrument sounds, and other musical details. 

How are duplicates defined technically?

Technically, if we say two music/video files are duplicates, which means every byte in both files is identical.
 

What to do if Cisdem Duplicate Finder missed scanning some duplicate music/videos?

Without a professional tool, You are not able to compare two files byte by byte. However, you can perform an initial check by comparing obvious file details, like file extension, duration, size, sample rate and bit rate. If any of these differ, the files are definitely not duplicates.

If none of those differ, please send some sample files to our support team at support@cisdem.com, our support team will do a byte comparison on our end.
 

In Conclusion

Cisdem Duplicate Finder can certainly scan duplicate music or video files, but there may be a difference between technical definition and what you have in mind. Hope this article helps clarify the difference and if you have any more questions about Cisdem Duplicate Finder, please feel free to contact our support team at support@cisdem.com
 

03 How Does Cisdem Duplicate Finder Detect Similar Images?

Since everyone may have a different idea of what counts as “similar”, and you may want to know: How does Cisdem Duplicate Finder detect similar images? What algorithms does it use? How accurate is the detection? In this guide, you will find the answers.
 

Cisdem mainly uses three algorithms to compare similar images, Histogram, pHash and Feature points. Understanding these 3 algorithms provides insight into how Cisdem Duplicate Finder detects similar images.
 

Histogram Comparison

A histogram looks at the overall color distribution in an image: how much red, green, blue, light, and dark it contains.

If two photos share a very similar mix of colors, Cisdem considers them similar.
 

pHash Comparison

pHash creates a kind of visual fingerprint for an image based on how it looks to the human eye. Even if the picture is resized, saved in another format, or slightly edited, its fingerprint usually remains close to the original.

It’s like recognizing a song. Whether it’s played on piano or guitar, the melody is the same, and you can still tell it’s the same tune.
 

Feature Points Comparison

Feature points are the distinct details in an image, like corners, edges or unique shapes. This method is very good at spotting similarities even if one image is rotated ,cropped or partly changes.

If you take two photos of the Eiffel Tower, once Cisdem detects the Eiffel Tower from the photos, they will be recognized as similar images regardless of shooting corner, scaling, resolution or other differences.
 

After understanding the above 3 algorthms, you will be able to choose a proper similarity comparison algorighm through the Similar images setting of Cisdem Duplicate Finder.

Smart Selection: This is the default option. Cisdem will automatically choose the most suitable algorithms based on your computer’s performance and the images being scanned.
 

Quality First: It uses Histogram and Feature points comparison, if you want to scan out images that are more alike, choose this option.  
 

Speed First: It uses pHash and Feature points comparison, if you need to scan a large number of images or want to scan faster, choose this option.
 

Conclusion

Cisdem Duplicate Finder employs three algorithms—Perceptual Hash (pHash), Histogram, and Feature Points—to detect similar images. Each algorithm has their own focus, and together，they ensure precise, reliable and comprehensive detection of similar images.