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Thermal + Visual Image Overlay

Overlay your thermal image precisely on a visual photo. Just mark the same spots on both images a few times and the tool automatically corrects perspective and lens distortion, giving you a single image that shows the hot spots at a glance. Free, with no install or sign-up, and your images are never uploaded to a server.

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Thermal0 pts
Visual0 pts

Overlay result

Press and hold the result image to save it (on a PC, right-click → Save image as). If you save your alignment points, next time you can just add the two images for an instant overlay.

Supported thermal cameras

Works with images from phone thermal cameras (thermal imagers) such as Seek Thermal, MILESEEY TR256i and TC01A. All you need is a thermal image and a visual photo of the same scene (JPG or PNG), whatever the camera.

How to use

  1. Select a thermal image and a visual photo.
  2. Click the same spot on each image, alternating thermal → visual: point 1, point 2, and so on. The image that gets the next point is outlined in blue.
  3. Press and hold a point to see a magnifier, and drag to move it.
  4. The overlay appears once you place 4 points. Fine-tune it with the opacity and offset sliders.
  5. Press and hold the result image (or right-click on a PC) to save it.

Frequently asked questions

Are my photos uploaded to a server?

No. All calculations happen only inside your browser, and your photos are not sent anywhere.

How many alignment points should I place?

Use 4 points for simple correction or long-distance shots, and 6 or more for close-ups so lens distortion can be corrected. You can place up to 9 points.

Can I reuse the same alignment points next time?

If you press Save alignment points, they are stored in this browser on this device, and from then on you only need to add the two images for an instant overlay. It works best when the images come from the same camera pair at a similar distance.

What is an acceptable average error?

A few pixels or less is a good match. Drag the points with the largest error back into place, or spread the points evenly across the whole image.

How to overlay a thermal image on a visual photo

If you use a phone thermal camera (Seek Thermal, MILESEEY TR256i, TC01A and the like), you probably know this problem.

"The thermal image shows temperatures, but I can't tell exactly which part of the wall this is!"

"I want to put the visual and thermal images side by side, or overlaid, in a report, but Photoshop is too much trouble..."

The easy fix is the 'Thermal + Visual Image Overlay' tool on EasyCVT. It aligns the two images accurately without distortion, right in your browser, with nothing to install and no sign-up.

💡 Why use EasyCVT thermal overlay

Thermal image of a TV and wall taken with a thermal camera Visual photo of the same scene Overlay of the thermal and visual images with adjustment sliders

🛠️ How to use (5 steps)

1. Load the images

After opening the page, add the [Thermal image] and the [Visual image] separately. (JPG and PNG are supported.)

2. Place alignment points alternately

Find the same spots in both images (corners, screw heads, other landmarks) and click them, alternating between the two images.

3. Choose the correction method

4. Adjust opacity and position

Once you have placed 4 or more points, a live preview appears below. Use the sliders to set the thermal opacity and fine-tune the position.

Thermal image in grayscale palette Page with the thermal and visual images loaded Magnifier that appears when you press and hold a point Fine-tuning an alignment point with the magnifier Six alignment points placed on the thermal and visual images Final overlay of the thermal and visual images

5. Save the result

On a PC, [right-click → Save image as]; on mobile, [press and hold the image → Save]. That's it!