Cleaning up documents with the Android Document Scanner

Document Cleanup lets the end user erase unwanted artifacts from a scanned page while preserving the underlying document content. Artifacts include handwriting, stamps, stains, fingers, shadows, and other distracting elements. The user paints over the regions to remove. The SDK then reconstructs a clean result image, with optional text preservation.

The Scanbot SDK ships a ready-to-use composable, DocumentCleanupCustomUI, that wraps the classic DocumentCleanup API and exposes brush controls, undo / redo / reset actions, pinch-to-zoom, and progress reporting. The host application stays in full control of the surrounding chrome (top bar, toolbar, buttons, sliders, etc.).

Usage of the Document Cleanup composable

The composable receives the page image as an ImageRef and renders an interactive canvas on top of it. Capture the DocumentCleanupActionController via onActionControllerCreated to trigger undo(), redo(), and reset() programmatically and to observe canUndo, canRedo, and progress.

Document Cleanup Custom UI Composable

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See full example on GitHub

Configuration options

Configure the cleanup behavior of the underlying engine through DocumentCleanupConfiguration. In the Ready-to-Use UI, pass it as screens.cleanup.engineConfiguration.

Property	Type	Default	Description
keepText	Boolean	true	If true, the SDK keeps detected text intact while the user erases around it. Text detection runs once up front and can take a moment, so construct the cleanup pipeline asynchronously to keep the UI responsive.
maxUndoRedoStackSize	Int	3	How many undo and redo steps the SDK keeps in memory. 0 turns off undo and redo. When the limit is exceeded, the oldest steps can no longer be undone.
maxCleanupResolution	Int	0	Caps the brushed area the SDK processes in one cleanup step, as width × height in pixels. Larger areas are processed at a lower resolution and scaled back up, which saves memory but can soften the edges near the stroke. 0 means no limit. For example, 1200000 keeps peak memory at about 0.5 GB for a 12 MP image. Prefer cleaning smaller areas over relying on this limit.
maxMaskBoundingBoxArea	Int	600000	Caps the area of the bounding box around the brushed mask, as width × height in pixels. If the mask is larger, the SDK skips the cleanup and returns the unchanged image with the status ERROR_MASK_TOO_LARGE. The undo and redo history stays as it is. Unlike maxCleanupResolution, this limit rejects the mask instead of lowering the quality, so you can ask the user to select a smaller area. 0 means no limit.

Cleanup status

A cleanup run reports a DocumentCleanupStatus alongside the resulting image:

Value	Meaning
OK	Cleanup completed at full resolution.
OK_BUT_REDUCED_QUALITY	Cleanup completed, but maxCleanupResolution forced an internal downscale of the cleanup region, so quality near the cleanup boundary may be reduced. If the result is not good enough, undo the last operation and apply cleanup on a smaller area.
ERROR_MASK_TOO_LARGE	The cleanup didn't run because the bounding box of the mask exceeds maxMaskBoundingBoxArea. The returned image is unchanged and the undo and redo history stays as it is. Retry with a smaller mask or raise the limit.

Composable parameters

In addition to documentCleanupConfiguration, DocumentCleanupCustomUI exposes the following parameters to customize appearance and interaction:

• image — the source ImageRef to be cleaned up.
• backgroundColor — color rendered behind the image canvas.
• brushSize — diameter of the drawing brush (in dp).
• brushColor — brush stroke preview color.
• maxZoomScale — maximum zoom factor supported by pinch-to-zoom.
• onActionControllerCreated — receives the DocumentCleanupActionController used to trigger undo() / redo() / reset() and to observe canUndo, canRedo and progress.
• onResultImageChanged — invoked after every successful cleanup, undo, redo or reset with the new result ImageRef. The composable owns that image, so don't close it.
• onProgressChanged — invoked with true when a heavy cleanup operation starts and false when it finishes; use it to drive a progress indicator.
• onError — invoked on SDK setup or cleanup failures.

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Scanbot SDK is part of the Apryse SDK product family

A mobile scan is just the start. With Apryse SDKs, you can expand mobile workflows into full cross‑platform document processing. Whether you need to edit PDFs, add secure digital signatures, or use a fast, customizable document viewer and editor, Apryse gives you the tools to build powerful features quickly.

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