The extents of a partial equirectangular panorama (not full spherical) can be specified using the haov, vaov, and vOffset parameters. These parameters will also be read from Photo Sphere XMP metadata, if present.
<iframe width="600" height="400" allowfullscreen style="border-style:none;" src="https://cdn.pannellum.org/2.2/pannellum.htm?panorama=https://pannellum.org/images/charles-street.jpg&haov=149.87&vaov=54.15&vOffset=1.17"></iframe>
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Partial panorama</title>
<link rel="stylesheet" href="https://cdn.pannellum.org/2.2/pannellum.css"/>
<script type="text/javascript" src="https://cdn.pannellum.org/2.2/pannellum.js"></script>
<style>
#panorama {
width: 600px;
height: 400px;
}
</style>
</head>
<body>
<div id="panorama"></div>
<script>
pannellum.viewer('panorama', {
"type": "equirectangular",
"panorama": "https://pannellum.org/images/charles-street.jpg",
"haov": 149.87,
"vaov": 54.15,
"vOffset": 1.17
});
</script>
</body>
</html>
Pannellum is developed on GitHub by Matthew Petroff.