{ "openapi": "3.1.1", "info": { "title": "Background Remover API", "version": "1.0.0", "summary": "Remove plain backgrounds from product photos and logos (colour-based, no AI) → transparent PNG.", "description": "Every endpoint performs the same calculation as the human page and returns inputs, result, units, assumptions, sources, warnings and computedAt. MCP endpoint: /mcp." }, "servers": [ { "url": "https://backgroundremover.usefulweb.site" } ], "paths": { "/api/v1/calculate": { "post": { "operationId": "calculate", "summary": "Remove plain backgrounds from product photos and logos (colour-based, no AI) → transparent PNG.", "description": "Makes the background of an image transparent by colour: it estimates the background colour from the image border and removes it with an adjustable tolerance, or removes one colour everywhere (chroma key / green screen). Works well for product photos, logos and scans on plain backgrounds; it does NOT understand people or complex scenes, because it uses no AI model.\n\nMethodology:\n- This is NOT an AI background remover. It decides per pixel by colour distance only, so it works for a subject on a plain, evenly coloured background (product shots, logos, scans, green screen) and fails on busy scenes, hair, or subjects with the same colour as the background.\n- Automatic mode shrinks the image to 200×200 px and takes the per-channel median of a 3-pixel border ring as the background colour. The share of border pixels within the tolerance (\"border uniformity\") predicts how well the method will work.\n- Edge-connected modes add a 1-pixel frame in the background colour and flood-fill from it with ImageMagick (-fuzz, -floodfill), so only background regions touching the edge are removed and same-coloured areas inside the subject stay. Chroma-key mode removes every pixel close to the colour, wherever it is.\n- The resulting mask is cleaned with a morphological open (removes specks) and close (fills pin holes) using a disk of the chosen radius, optionally blurred to feather the edge, and used as the alpha channel of a PNG.\n- Existing transparency is flattened onto white first. Colour tolerance is a root-mean-square distance over R, G and B relative to the full 0–255 range.\n\nColour-based removal is approximate. Check the edges in the preview; for portraits or complex scenes use an AI tool or manual masking.", "tags": [ "media" ], "x-mcp-tool": "background_remover", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/BackgroundRemoverInput" }, "examples": { "example1": { "summary": "Red square on white (automatic)", "value": { "file": { "filename": "product.png", "contentType": "image/png", "contentBase64": "iVBORw0KGgoAAAANSUhEUgAAACAAAAAgAQMAAABJtOi3AAAABlBMVEX/////AADrWueTAAAAEklEQVQI12NgIBb8/09dgjgAAPcnH+GApkH4AAAAAElFTkSuQmCC" }, "mode": "auto", "fuzz": 10, "cleanup": 1, "feather": 0 } }, "example2": { "summary": "Chroma key: remove white everywhere", "value": { "file": { "filename": "logo.png", "contentType": "image/png", "contentBase64": "iVBORw0KGgoAAAANSUhEUgAAACAAAAAgAQMAAABJtOi3AAAABlBMVEX/////AADrWueTAAAAEklEQVQI12NgIBb8/09dgjgAAPcnH+GApkH4AAAAAElFTkSuQmCC" }, "mode": "chroma", "color": "#ffffff", "fuzz": 5, "cleanup": 0, "feather": 0 } } } } } }, "responses": { "200": { "description": "Calculation result envelope.", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/BackgroundRemoverResult" } } } }, "400": { "description": "Malformed JSON body.", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "422": { "description": "Invalid input (see errors[]).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } }, "429": { "description": "Rate limit exceeded (see Retry-After).", "content": { "application/problem+json": { "schema": { "$ref": "#/components/schemas/Problem" } } } } } } }, "/api/v1/tool": { "get": { "operationId": "getToolDefinition", "summary": "Inputs, output schema and examples for this tool", "responses": { "200": { "description": "Tool definition.", "content": { "application/json": { "schema": { "type": "object" } } } } } } } }, "components": { "schemas": { "Problem": { "type": "object", "description": "RFC 9457 problem details. 422 responses include per-field `errors`.", "required": [ "type", "title", "status", "detail" ], "properties": { "type": { "type": "string" }, "title": { "type": "string" }, "status": { "type": "integer" }, "detail": { "type": "string" }, "code": { "type": "string" }, "errors": { "type": "array", "items": { "type": "object", "required": [ "field", "message" ], "properties": { "field": { "type": "string" }, "message": { "type": "string" } } } } } }, "BackgroundRemoverInput": { "type": "object", "additionalProperties": false, "properties": { "file": { "title": "Image", "description": "JPG, PNG, WebP, AVIF, GIF, TIFF or HEIC, max 50 MB. Best results: the subject on a plain, evenly lit background. Upload as {filename, contentType?, contentBase64}. Max 51200 KiB. Accepts .jpg,.jpeg,.png,.webp,.avif,.gif,.tif,.tiff,.heic,.heif,image/jpeg,image/png,image/webp,image/avif,image/gif,image/tiff,image/heic,image/heif.", "type": "object", "additionalProperties": false, "required": [ "filename", "contentBase64" ], "properties": { "filename": { "type": "string" }, "contentType": { "type": "string" }, "contentBase64": { "type": "string" } } }, "mode": { "title": "Method", "type": "string", "enum": [ "auto", "color-connected", "chroma" ], "default": "auto" }, "color": { "title": "Background colour", "description": "Hex colour, e.g. #ffffff or #00ff00. Required for the two colour methods; ignored by the automatic method.", "type": "string", "maxLength": 7 }, "fuzz": { "title": "Colour tolerance", "description": "How different a pixel may be from the background colour and still be removed. Raise it for shadows or JPEG noise; lower it if parts of the subject disappear.", "type": "number", "minimum": 0, "maximum": 60, "default": 12, "x-unit": "%" }, "cleanup": { "title": "Edge clean-up", "description": "Removes isolated specks and fills small holes in the mask (morphological open/close). 0 = off.", "type": "integer", "minimum": 0, "maximum": 8, "default": 1, "x-unit": "px" }, "feather": { "title": "Feather edges", "description": "Softens the cut-out edge. 0 = hard edge.", "type": "number", "minimum": 0, "maximum": 10, "default": 0.5, "x-unit": "px" } }, "required": [ "file" ] }, "BackgroundRemoverResult": { "type": "object", "additionalProperties": false, "required": [ "schemaVersion", "tool", "computedAt", "inputs", "summary", "result", "units", "assumptions", "sources", "warnings", "presentation", "links" ], "properties": { "schemaVersion": { "type": "string", "const": "1.0" }, "tool": { "type": "object", "additionalProperties": false, "required": [ "id", "name", "version" ], "properties": { "id": { "type": "string" }, "name": { "type": "string" }, "version": { "type": "string" } } }, "computedAt": { "type": "string", "format": "date-time" }, "inputs": { "type": "object", "description": "Normalised inputs actually used, including applied defaults." }, "summary": { "type": "string" }, "result": { "type": "object", "additionalProperties": false, "required": [ "mode", "backgroundColor", "fuzzPercent", "borderUniformityPercent", "suitability", "foregroundPercent", "removedPercent", "width", "height", "method", "artifact", "preview" ], "properties": { "mode": { "type": "string", "enum": [ "auto", "color-connected", "chroma" ] }, "backgroundColor": { "type": "string", "description": "Hex colour that was removed." }, "fuzzPercent": { "type": "number" }, "borderUniformityPercent": { "type": "number", "description": "Share of border pixels within the tolerance of the background colour." }, "suitability": { "type": "string", "enum": [ "good", "fair", "poor" ] }, "foregroundPercent": { "type": "number" }, "removedPercent": { "type": "number" }, "width": { "type": "integer" }, "height": { "type": "integer" }, "method": { "type": "string", "enum": [ "colour-distance (non-ML)" ] }, "artifact": { "type": "object", "additionalProperties": false, "required": [ "artifactId", "filename", "mime", "bytes", "sha256", "path" ], "properties": { "artifactId": { "type": "string" }, "filename": { "type": "string" }, "mime": { "type": "string" }, "bytes": { "type": "integer" }, "sha256": { "type": "string" }, "path": { "type": "string", "description": "Download path on the same site (valid for about 2 hours)." } } }, "preview": { "type": "object", "additionalProperties": false, "required": [ "artifactId", "filename", "mime", "bytes", "sha256", "path" ], "properties": { "artifactId": { "type": "string" }, "filename": { "type": "string" }, "mime": { "type": "string" }, "bytes": { "type": "integer" }, "sha256": { "type": "string" }, "path": { "type": "string", "description": "Download path on the same site (valid for about 2 hours)." } } } } }, "units": { "type": "object", "additionalProperties": { "type": "string" } }, "assumptions": { "type": "array", "items": { "type": "string" } }, "sources": { "type": "array", "items": { "type": "object", "additionalProperties": false, "required": [ "title" ], "properties": { "title": { "type": "string" }, "url": { "type": "string" }, "publisher": { "type": "string" }, "retrievedAt": { "type": "string" }, "note": { "type": "string" } } } }, "warnings": { "type": "array", "items": { "type": "string" } }, "presentation": { "type": "array", "items": { "type": "object" }, "description": "Display blocks used by the human page (same data)." }, "links": { "type": "object", "additionalProperties": false, "required": [ "human", "api", "openapi", "methodology" ], "properties": { "human": { "type": "string", "format": "uri" }, "api": { "type": "string", "format": "uri" }, "openapi": { "type": "string", "format": "uri" }, "methodology": { "type": "string", "format": "uri" } } } } } } } }