Image difference overlay
Open Image difference overlay on Happytails.ai. This view has the same page content and links, with explicit tool capabilities. Read the processing notes before using a tool.
Tool capabilities
{
"id": "image-difference-overlay",
"category": "image-tools",
"built": true,
"requirements": "Files stay in this browser. Use still PNG, JPEG or WebP images, up to 20 MiB per file, 40 MiB combined and 16 million decoded pixels combined. Outputs total at most 100 MiB. Processing stops after 30 seconds. Source metadata and color profiles are not copied.",
"implementation": {
"fields": [
{
"key": "offsetX",
"label": "Second image horizontal offset",
"value": 0,
"type": "number",
"min": -16384,
"max": 16384,
"step": 1
},
{
"key": "offsetY",
"label": "Second image vertical offset",
"value": 0,
"type": "number",
"min": -16384,
"max": 16384,
"step": 1
},
{
"key": "threshold",
"label": "Channel difference threshold",
"value": 0,
"type": "number",
"min": 0,
"max": 255,
"step": 1
},
{
"key": "opacity",
"label": "Highlight opacity",
"value": 0.65,
"type": "number",
"min": 0,
"max": 1,
"step": 0.05
}
],
"registrationFamily": "raster-image-studio",
"files": true,
"input": false,
"multiple": true,
"accept": ".png,.jpg,.jpeg,.webp",
"maxFileBytes": 41943040,
"deferImagePreview": true,
"note": "Files stay in this browser. Use still PNG, JPEG or WebP images, up to 20 MiB per file, 40 MiB combined and 16 million decoded pixels combined. Outputs total at most 100 MiB. Processing stops after 30 seconds. Source metadata and color profiles are not copied.",
"experience": {
"automatic": false,
"single": false,
"inputMaxLength": 1000000,
"inputMode": "text",
"label": "Your text",
"placeholder": "Type or paste your input…",
"help": "Up to 1,000,000 characters. Review the settings before running.",
"helpParts": [
"Up to 1,000,000 characters.",
"Review the settings before running."
],
"action": null
},
"mode": "explicit",
"interactive": false
},
"execution": "Browser interface",
"api": null,
"browser_agent": {
"supported": true,
"name": "run_current_tool",
"discovery": "WebMCP on the human page in a supporting browser",
"verification": "See audit/API-AUDIT.md; availability is not verification"
}
}Page guide
Compare two images on the same pixel grid. Download the difference image, highlighted overlay and change mask.
How to use Image difference overlay
- Choose two still images in the order shown in the file list.
- Align the second image with horizontal and vertical offsets, then set a difference threshold.
- Run the comparison and download the images or report.
Useful next steps
Align before comparing
Offsets place the second image within the first image’s coordinate grid. Regions without overlap are shown in magenta on the difference image and mask, and counted separately.
A precise pixel comparison
A pixel changes when its largest decoded RGBA channel difference is greater than the threshold. The red overlay shows changed pixels. This is not a perceptual similarity score.