Most of the images produced nowadays are very high-resolution. High-resolution images are now a commodity resource, with the impressive evolution of digital photography (just to mention a single example, a recent off-the-shelf smartphone provides a 41 Mpixel camera). When high- or huge-resolution images are available, the visualization on the web can be difficult, due to the amount of data that have to be transmitted before the web browser would be able to present visually something. This is because the browser has to receive the entire file before visualizing it. Another important and critical issue could be the necessity to protect the data, avoiding sending the full resolution image as a single file to a remote host.
This service converts a high-resolution image (uploaded using standard image formats) into a multi-resolution version, enabling progressive transmission and rendering it by means of a web visualization page.
We offer a service for converting a high-resolution image (uploaded using standard image formats) into a multiresolution format, enabling progressive transmission and visualization by means of a web-enabled image-browser.
Our service is based on WebGL, SpiderGL and 3DHOP (3D Heritage On-Line Presenter), where the latter are platforms designed and implemented by CNR-ISTI. The main advantage of this service is that the handling of the image doesn’t need the installation of a local server.
The service is totally automatic: you have first to fill a simple web form with some info on the image you are willing to convert, and then upload the image. Our service will convert your model, will store it on a web server and will return you a URL you may use to access the data.
According to user needs, we can also return a .zip file containing all the data produced, to allow the user to store the data on his preferred web server.
Please note: the server accepts in input images encoded with the .png, .jpg, .tif formats.
The service transforms each image in a web-compliant format. Following the approach used by Google Maps, the high-resolution image will be regularly divided in chunks and a hierarchy of images at different resolution is produced from these chunks. Each image of this sequence is splitting in square tiles of fixed size (usually 256 pixels) to permit the data management at high granularity. The client in the browser “composes” on the fly the portion of the image selected by the user using the tiles more suitable according to the size of the portion under view. This approach is a simple multi-resolution one that has been demonstrated to be very efficient to visualize this type of data. The same approach can be employed to visualize high- or huge- resolution images. The image visualization webpage we produce allows to navigate the model in a WebGL frame (no plugin have to be installed, it will work natively on all the main browsers supporting WebGL, with the current exception of smartphones and tablets).
M. Corsini, M. Dellepiane, U. Dercks, F. Ponchio, M. Callieri, D. Keultjes, A. Marinello, R. Sigismondi, R. Scopigno, G. Wolf,
CENOBIUM - Putting together the Romanesque Cloister Capitals of the Mediterranean Region,
BAR International Series , Volume 2118, page 189-194 - 2010