Crop image grid

Open sprite sheets and image grids locally, align the grid precisely, select cells, and export the slices as PNG files.

Features

• Lokale Bildverarbeitung
• Präzise Rasterausrichtung
• Mehrfachauswahl
• PNG-Export

This manual describes the implemented desktop and web workspace. The embedded HTML excerpts are sanitized, non-wired copies of the real AT structure; they demonstrate layout and accessibility without executing image operations.

Source images

Control	Effect
Repository	Opens the repository subview. Activating or double-clicking a PNG, JPEG, or WebP resource loads its current revision.
Grid	Opens the numeric grid properties.
Show all compatible images / Show sprite sheets only	Disables or restores the default sprite-sheet resource-class filter.
List view / Grid view	Switches the repository result presentation.
Refresh repository	Reloads repository results.
Close / open sidebar	Collapses or reopens either sidebar.
Sidebar resize handle / arrow keys / double-click	Changes that sidebar width; double-click restores its default width.
Open image (web)	Opens the native file picker for PNG, JPEG, or WebP.
Drop image here	Loads a compatible local file. Replacing an already loaded source requires confirmation.
Cancel / Replace	Keeps the current image or accepts the newly selected image while retaining the grid configuration.

Repository subview – visual excerpt

Main toolbar

IconButton	Button	Effect
	Apply crop configuration / Download slices	Opens export. It is disabled without a source or valid slices.
	Undo	Restores the previous grid, cell, lock, or detection state.
	Reset grid	Restores initial grid geometry, offsets, locks, selection, and detection threshold.
	Fit view	Fits the source image to the canvas.
32	Alpha 32 / 64 / 128 / 192 / 224	Runs automatic transparent-grid detection with the selected alpha threshold.
	Select grid manually	Toggles direct manipulation of the whole grid frame.
	Lock X / Lock Y	Prevents movement of the selected cell on the corresponding axis.
	Align all slices to visible X content	Aligns slices to the measured visible X anchor of the selected master.
	Align all slices to visible lower Y edge	Aligns slices to the measured visible lower Y edge of the selected master.
	Center cell	Removes the selected cell's individual offset.

All five presets are separate buttons: Alpha 32, Alpha 64, Alpha 128, Alpha 192 and Alpha 224.

Grid properties and canvas

Rows, columns, cell width, cell height, gap X, gap Y, offset X, and offset Y are edited in the AT Property Grid. Arrow keys move the selected grid or cell by one pixel; Shift plus arrow moves by ten. Dragging the grid frame or move handle moves the whole grid; dragging the resize handle changes cell width and height; dragging a selected cell center moves only that slice. Mouse wheel zooms the canvas, Space or the middle mouse button plus drag pans it, and Fit view restores the fitted viewport.

Property Grid – visual excerpt

Slice preview and zoom

Clicking a preview card Rxx · Cxx selects the cell. Enlarge Rxx · Cxx opens the enlarged slice and remains marked while active. Zoom out, Zoom in, Reset zoom, and Close zoom operate between 100 and 400 percent. The ruler keeps tick marks but suppresses overlapping numeric labels. In zoom mode, arrow keys or direct pointer drag move the visible source beneath the fixed crop; the mouse wheel changes zoom between 100 and 400 percent.

Preview card and zoom toolbar – visual excerpts

Export

Control	Effect
Close export	Closes the export overlay without running the operation.
Movement ID	Defines movement ID, movement name, and the filename prefix.
Frame duration (ms)	Sets each frame duration from 16 to 60000 ms.
Loop movement	Toggles movement looping.
Resize on save	Enables output scaling.
Mode: Percentage / Absolute	Selects percentage or fixed-size scaling; disabling resizing keeps the original cell size.
Percentage	Sets relative output size from 1 to 1000 percent.
Keep aspect ratio	Couples width and height during absolute scaling.
Width / Height	Sets the absolute output dimensions within 1 to 4096 pixels.
Interpolation	Selects Nearest Neighbor, medium smoothing, or high-quality smoothing.
Slice card	Includes or excludes a frame from export.
Filename	Changes the individual frame suffix.
Save to repository (desktop)	Creates the .akmovement container locally and stores it with typed metadata through the repository host.
Download PNG files (web)	Renders and downloads the selected frames locally; no repository or network service is used.

Export view – visual excerpt

Automatic saving

Grid and export configuration changes are persisted automatically. The current repository source, selected cell, axis locks, and sidebar state are stored in ToolStorage and restored when available. Local dropped image bytes are deliberately not copied into ToolStorage.

Requirements

Use one PNG, JPEG, or WebP image up to the documented 50 MB input limit. Web use requires a current browser with Canvas, File, and Download support.

Steps

Open a source image, choose an alpha preset or edit the grid manually, inspect and correct slices, select export frames, configure playback and optional resizing, then save to the repository or download PNG files.

Parameters

Grid rows, columns, cell dimensions, gaps, offsets, alpha threshold, axis locks, frame selection, duration, loop mode, resize dimensions, aspect-ratio handling, and interpolation control the result.

Result

Desktop export stores an .akmovement resource with its selected frame images and metadata; web export downloads the selected PNG slices locally.

Common errors

A missing source keeps source-dependent actions disabled. Invalid IDs, dimensions, selections, duration, or interpolation are rejected before image processing. If automatic detection does not match an irregular sheet, try another alpha threshold and then correct rows, columns, cell size, gaps, and offsets manually.

Troubleshooting

If a grid is not detected correctly, choose a different alpha threshold, verify the source transparency, and then refine the grid geometry manually.