SnapOtter/apps/docs/tools/image/stitch.md

Stitch / Combine

Join multiple images side by side, stacked vertically, or arranged in a grid. Supports alignment, gap, border, corner radius, and multiple resize modes.

API Endpoint

POST /api/v1/tools/image/stitch

Parameters

Parameter	Type	Required	Default	Description
direction	string	No	"horizontal"	Layout direction: horizontal, vertical, grid
gridColumns	integer	No	2	Number of columns when direction is grid (2 to 100)
resizeMode	string	No	"fit"	How images are resized: fit, original, stretch, crop
alignment	string	No	"center"	Cross-axis alignment: start, center, end
gap	number	No	0	Gap between images in pixels (0 to 1000)
border	number	No	0	Outer border width in pixels (0 to 500)
cornerRadius	number	No	0	Corner radius applied to final output (0 to 500)
backgroundColor	string	No	"#FFFFFF"	Background/border color as hex (e.g. #FF0000)
format	string	No	"png"	Output format: png, jpeg, webp, avif, jxl
quality	number	No	90	Output quality (1 to 100)

Example Request

curl -X POST http://localhost:1349/api/v1/tools/image/stitch \
  -F "file=@image1.png" \
  -F "file=@image2.png" \
  -F "file=@image3.png" \
  -F 'settings={"direction":"horizontal","resizeMode":"fit","gap":10,"backgroundColor":"#FFFFFF","format":"png"}'

Example Response

{
  "jobId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "downloadUrl": "/api/v1/download/a1b2c3d4-e5f6-7890-abcd-ef1234567890/stitch.png",
  "originalSize": 1234567,
  "processedSize": 987654
}

Notes

• Requires at least 2 images. Upload multiple image files in the multipart request.
• Supports HEIC, RAW, PSD, and SVG input formats (automatically decoded).
• Resize modes:
  • fit - Scale images to match the smallest dimension along the joining axis.
  • original - Keep original sizes (may produce uneven edges).
  • stretch - Force images to match the smallest dimension without preserving aspect ratio.
  • crop - Cover-crop images to match the smallest dimension.
• In grid mode, cells are sized to the median dimensions of all images.
• The cornerRadius is applied to the entire final output, not individual images.
• Canvas size is limited by the MAX_CANVAS_PIXELS server configuration to prevent memory exhaustion.