// This script makes a copy merged based on selection, calculate the right size
// create a new doc based on the selection size, and paste it into the doc
// written by Allen Jeng, Adobe Systems Inc., Photoshop QE Team
// Amended by Peter Lewis - www.peteralewis.co.uk to handle transparent images and resize to image not selection.
// Please note if you don't have any layers, you may get an error (as it can't copy merged), simply remove the "true" on line 16.

// get the width and height of selection
var calcWidth  = app.activeDocument.selection.bounds[2] - app.activeDocument.selection.bounds[0];
var calcHeight = app.activeDocument.selection.bounds[3] - app.activeDocument.selection.bounds[1];

// get the document resolution
var docResolution = app.activeDocument.resolution;
var docResolution = app.activeDocument.resolution;

// copy merged
app.activeDocument.selection.copy(true);

// create a new doc based on selection size
var myNewDoc = app.documents.add(calcWidth, calcHeight, docResolution, "New Image", NewDocumentMode.RGB, DocumentFill.TRANSPARENT);

// paste in from clipboard
myNewDoc.paste();

//###   Trim the document to remove excess transparent area   ###
app.activeDocument.trim(TrimType.TRANSPARENT);