SCREENCAST-MCP / TOOLS / WATCH
Screen Diff
screen_diff
Compare two screenshots or frames: SSIM score, changed share, and changed boxes in b's pixels, to check a UI change happened only where expected.
watchread-onlyidempotentsince v0.18.0
00:00PARAMETERS
| Name | Type | Description |
|---|---|---|
a required | string | Before image (or video: first frame). |
b required | string | After image (or video); scaled to a's size. |
pixelThreshold | number | Mean 0-255 difference for a ~32x32 cell to count as changed (default 12). ≥ 0, ≤ 255 |
returnImage | boolean | Return b inline with changes outlined (default true). |
00:05A MINIMAL CALL
screen_diff { "a": "before.png", "b": "after.png" }The required arguments only, with placeholder values. Everything else takes its default.
00:10WHAT COMES BACK
Structured content (structuredContent), alongside a text summary:
| Field | Type |
|---|---|
identical always | boolean |
ssim always | number | null |
meanDiff always | number |
changedFraction always | number |
regions always | any[] |
00:15SEEN IN