Perspective Viewer

Perspective Viewer is used to do page boundaries manual adjustment & perspective transformation. The page data displayed on this viewer is its original data.

const perspectiveViewer = new Dynamsoft.DDV.PerspectiveViewer({
    container: document.getElementById("viewer"),
});

perspectiveViewer.openDocument("docUid"); // Open a document which has pages

Quadrilateral selection

Quadrilateral Selection in the perspective viewer means the selection which will be perspective transformed.

Quad selection

In addition to drawing and adjusting the selection through the UI, DDV also provides some additional interfaces to operate the selection.

Set a quadrilateral selection on the current page by using setQuadSelection(). If the selection is exceeds the bounds of the current page, it won’t take effect.

  const quad = [
      [314,518],
      [2200,625],
      [2204,3339],
      [176,3048]
  ];

  perspectiveViewer.setQuadSelection(quad);

Get the quadrilateral selection on the current page by using getQuadSelection().
```
  const quad = perspectiveViewer.getQuadSelection();
```
Reset the quadrilateral selection to the original one by using resetQuadSelection(). The original selection on the page can be detected by Document Detect during capturing in the capture viewer or set by ExtraPageData in loadSource() when loading the page. If it is not detected or set before, the original selection would be the whole page range.
```
  perspectiveViewer.resetQuadSelection();
```

Perspective transformation

Perspective transformation in the perspective viewer is to rectify the quadrilateral selection. It is implemented by the method applyPerspective().

const quad = perspectiveViewer.getQuadSelection();
await perspectiveViewer.applyPerspective(quad);