Video Blurring Techniques for attachments

This guide details two methods for blurring video content as part of our internalthis processes. These methods utilize Kdenlive and Capcut for PC, both versatile and user-friendly video editing tools. Each tutorial will walk you through the blurring process from start to finish.

Tutorial 1: Blurring Videos Using Kdenlive

Overview

Kdenlive is an open-source video editor ideal for precise blurring needs. Works under Windows, Linux and Mac OS-es. This guide will show you how to use its built-in tools to apply blur to specific parts of a video.

Step-by-Step Guide

1. Open the Setup file, and install the app
2. Run Kdenlive

3. Right click on the Project Bin panel (1) and, from context menu, choose Add Clip or Folder (2)

4. Select video to edit

• Some high resolution/high quality videos (mainly from Samsung and iPhones – recorded with variable frame rate) may require transcoding before edition which will be done automatically.
• For nonstandard resolutions, the program will ask to create a new profile. Confirm clicking ”Continue”.

5. Drag and drop newly added clip onto timeline

6. We will only use two tools to edit the video: Selection Tool (1) and Razor Tool (2)

7. First, you may trim unwanted parts from beginning and end of video:

• Move pointer (1) on timeline (2) to the new beginning. On Project monitor (3) you will see the current frame.

8. Select Razor Tool (1) and set cursor over frame pointer on timeline (2). Click to cut the clip.

9. Now you have two separate clips.

10. Right-click the clip on the left and choose ”Delete selected item”.

11. In a similar way, we will select the first fragment of the film to be pixelated

• Select Razor Tool
• Position the cursor on the timeline at the beginning of the fragment you want to pixelate and click.
• Position the cursor on the timeline at the end of the fragment you want to pixelate and click.
  • You will get three video fragments on the timeline (1) (2) (3). Switch to Selection Tool (4) to select the middle one, which will be the fragment to pixelate (5).

12. Select ”Effects” tab (1). In search box (2) type ”Obscure” to find the effect.

• Drag and drop Obscure effect onto the middle fragment of video.

13. Newly added effects will appear on the Effect tab (1).

• Additionally on the Project Monitor tab you will see a red frame which indicates part of the video to pixelate.
• You can adjust the size and position of the area to pixelate using the handles in the corners.

14. Repeat above steps to select another part of video (1) to pixelate. Each part may have pixelated different portions of screen (2).

15. You may also pixelate two (or more) separate parts of the video at once.

• Just add the ”Obscure” effect twice.
• On the Effect tab you will see two controls. Clicking on each one you can control the size of pixelated parts of video.

16. When finished choose Project (1) and Render…(2) to export pixelated video.

17. In the ”Rendering” window:

• Choose file name for new video (1)
• Check ”More options” (2)
• Select video codec (3) – default MP4-H624/AAC should be fine.
• If audio is not necessary uncheck the „Audio” box.

18. Set video quality. Lover quality means smaller file size.

• Optionally you may check ”Paraller Processing” and set Threads to higher limits – which may speed up rendering.
• Choose ”Full project” to render (default).
• Click ”Render to file” to start processing.

19. On the ”Job Queue” tab you can check progress.

Tips and Best Practices

• Use Keyframes to adjust blur movement with the subject if it moves.
• Test different blur types (e.g., Gaussian or Box Blur) to find what works best for your project.

Tutorial 2: Blurring Videos Using Capcut for PC

Overview

Capcut for PC is a free, user-friendly video editing tool with intuitive controls, ideal for quick blurring tasks.

Step-by-Step Guide

1. Install Capcut for PC and Open it
2. Select Create a new project
3. Click Import (and import your video)
4. Drag the uploaded video to the lower part of the screen  (“Drag material here and start to create”)

5. Move to the first frame of the video that you want to blur a field
6. Go to Stickers and search for “blur”. Select a sticker with blurring effects (do not use different types of stickers like emojis, tapes, and so). Click + icon near to the sticker

7. Adjust the size of the Sticker just added to the video
8. On the lower Menu resize the bar that defines the duration of the Sticker appearance

9. Select the Sticker. On the right side of the screen (Sticker Menu) in the Position line select the lozenge to “Add a Keyframe”

10. Select another frame of your video 30<>40s later, adjust the position of your Sticker to cover the desired field and Add a Keyframe

• Repeat the steps above several times to add several keyframes in several parts of the video so the Stiker will “follow” the keyframe and cover the desired field
• For the parts of the video that the movement is too fast it is impossible to follow exactly the field to be covered. For these moments you can blur the entire screen : Effects>Video Effects> Blur>Add (Make sure to resize the duration of the “blur effect” to be the shortest period possible.

11. After all editions are complete you can go to Menu>File>Export to save the video on your PC.

Final Recommendations

Both methods are effective; choose based on the project complexity:

• Kdenlive offers advanced control with more detailed settings, ideal for complex blurring tasks.
• Capcut is more streamlined, better for quick, straightforward edits.

Good example of Blurred Video - Mobile Web
Good example of Blurred Video- Desktop Web

By following these guidelines, you should be able to blur video content effectively for any of our internal projects.