Choosing what of each page ends up on screen.
A scanned page is rarely the shape of a video frame. Crop to pick out the part that matters — a single column, one staff system, one cell of a sprite sheet — and it happens in the preview, above the timeline.
Drag across the preview to draw a rectangle. Drag inside a rectangle to move it, or drag an edge or a corner to resize. Esc clears it — one press per rectangle, the most recent first.
Nothing has changed yet: the rectangle is a proposal. Commit it by pressing Return or choosing Crop to Selection, which replaces the item with the cropped result.
You can draw more than one rectangle on a page. Each becomes its own item when the crops are applied, in the order they sit on the page — turning a page of several columns into several timeline items.
With several on a page, click a rectangle to select it — a selected rectangle draws its perimeter in bold — and ⇧-click to add another to the selection or take it out again. ⌫, or Remove Selected Crop Rects from the context menu, gets rid of the first rectangle, or one in the middle, without disturbing the rest; a single ⌘Z brings them back.
Clicking the page outside every rectangle drops the selection, and clicking it again clears the rectangles. Esc works the same way round: it deselects first, then goes back to clearing one rectangle per press.
To take a crop off again, use Remove crop from the preview's context menu. The original is kept, so nothing is lost by cropping — the full page comes back, and the rectangle that made the crop comes back with it, staged where it was. A crop that came out a little tight just needs a nudge of one edge and another Return, rather than a rectangle redrawn from scratch.
⌘Z straight after committing does the same thing from the other direction: it restores the page and hands back the rectangle you drew.
The detection tools only touch uncropped pages, so to clear a whole project at once, use Remove All Crops in the Tools menu. It asks before it runs, and lists in numbers what it is about to do: how many items carry a crop, how many pages those were cut from, and how many staged rectangles it will discard along with them.
A page split into several crops became several items, so it also asks what should happen to those. Merge back into one page gives each page back as the single page its crops were cut from. With Keep the project's total length on, that page takes the combined duration of the items it replaces, so nothing timed against it moves; turn it off and each page keeps its own duration, which leaves the project shorter. Keep every item removes nothing and hands each item the whole page instead. However it runs, and however far it gets before you cancel it, the whole thing is one ⌘Z.
If the edges feel fiddly to grab, Settings has Expand crop-rect resize zones beyond the rectangle's edges, which widens the target area without changing the rectangle.
Scanned pages tend to want the same crop over and over, so copy a rectangle from one page to the next rather than redraw it.
| Command | What it does |
|---|---|
| ⌘C | Copies the rectangles on this page — all of them, not just one. |
| ⌘X | Copies and removes them. |
| ⌘V | Pastes onto the current page. |
| Apply Crop to All | Applies the current crop rectangles on every page in the project at once. |
Pasting does not drop the rectangle on top of what is already there. If the page already has rectangles, paste places the new one beside them, in the first free space it finds.
The two paste commands differ only in which direction it tries first:
| Command | Looks for space |
|---|---|
| ⌘V — Paste | Below first, then right, then above, then left. |
| ⌥⌘V — Paste Row First | Right first, then below, then above, then left. |
Build up a page read in columns with plain paste, and a page read in rows — a sprite sheet, a grid of panels — with Paste Row First. Paste does nothing on a page that is already cropped.
Inset / Outset Crop Rects, in the preview's context menu, grows or shrinks every rectangle at once. Useful when a batch of crops all came out a little tight, or all take in a few millimetres of scanner shadow.
It takes a horizontal and a vertical amount, in pixels, as a percentage of the source image, or as a percentage of each rectangle. There is also a horizontal and vertical offset, for shifting rather than resizing.
Rectangles are staged until you commit them. This lets the detection tools propose crops across a whole project without changing anything, and lets you look before agreeing.
You can interrupt both halves of a long run. While detection is searching, and again while it commits the staged rectangles, the progress panel carries a Cancel button, and ⌘. does the same while that panel is on screen. Cancelling detection discards what it had found, since nothing has been changed yet. Cancelling the commit keeps the pages it has already cropped — all of them inside a single undo group, so one Undo still takes the whole run back.
Three tools work out the rectangles themselves and stage them for review. Two of them run over the whole project and live in the Tools menu; the third works on one page and is on the preview's own context menu.
Reads the text on every uncropped page and stages crops around it, so a video can follow a narration a paragraph or a line at a time rather than a page at a time.
| Mode | What it produces |
|---|---|
| Paragraphs | One crop per detected paragraph. |
| Segments | A set number of blocks per page, the splits snapping to paragraph boundaries. |
| Lines | Every N lines, either flowing across paragraph breaks or respecting them. |
Three further settings decide the shape of each crop rather than where it falls:
For a page that is a grid: a sprite sheet, a contact sheet, a page of panels. Right-click the preview and choose Split into Grid. It works on the page you are looking at, and appears only while that page is uncropped.
It looks at the picture first, finding the gaps between the cells, and stages a rectangle for each cell it finds. Where the cells are drawn against a plain background that is usually the whole job.
When it cannot make the cells out, it asks instead: rows and columns, plus an outer margin and a gutter as percentages, and lays a regular grid over the page. Either way the rectangles are staged, so you can adjust any that came out wrong before committing.
Finds the staff systems on a score and crops each out — covered in full on the sheet music page.
All three leave already-cropped pages alone — to run one over pages that are already cropped, take the crops off first with Remove All Crops — and all three remember their settings with the project rather than across projects, so a book and a score can keep different answers.
An overlay is a coloured rectangle drawn over the page rather than a cut taken out of it — for covering something up. An answer in a workbook, a name on a scanned document, a watermark you would rather not show.
Hold ⇧ and drag to draw one. The gesture is the same one that draws a crop rectangle; ⇧ tells the two apart.
Right-click an overlay for Change Color, which takes any colour and any opacity, or Remove Overlay. ⇧-click adds an overlay to the selection or takes it out again, so you can recolour or remove several in one go — ⌫ removes whatever is selected.
Overlays belong to the page, so cropping a page that carries one clips the overlay along with everything else.
Overlays and crop rectangles share the same drag gestures, so ClapperBoard only lets you work on one at a time: while any crop rectangle exists on the page, you can neither grab nor draw overlays — ⇧ selects crop rectangles for as long as they are there. Clear the rectangles first, and the overlays become editable again.