I wanted a framed print of The Lady with an Ermine when we were redesigning our workspace during lockdown. Important works such as this painting by Leonardo da Vinci usually have high-resolution images online. The typical sources are Wikimedia Commons and Google Arts and Culture.
The Lady with an Ermine has a high resolution copy on Wikimedia but the highest version only has a dimension of 2,048 pixels × 2,754 pixels. That is good enough for print but I wanted an even higher resolution.
There’s one in Google Arts and Culture – a zoomable version with ultra-high resolution that will allow you to focus on minor details of the work. The only problem is you can’t directly download images from the site. There are some works that you can download, such as those made publicly available by The Metropolitan Museum of Art, but most images you can’t.
To be able to download images from Google Arts and Culture, you can run a script such as Dezoomify. It has a web version and even a browser extension but I prefer the script. What Dezoomify does is download the maximum resolution of an image by getting it by tiles, which are the portions shown when zooming, and then reassembling it to its full quality.
If you download the script, all you need to do is run it, paste the address of the Google Arts and Culture image you want to download, choose the image resolution, and it takes care of the entire process. With The Lady with an Ermine, for example, the script took 5,002 tiles to download a 30,894 pixels x 41,545 pixels JPEG image with a total file size of 114 mb.
According to its project page, Dezoomify also works with other online resources such as the National Gallery of Art, Harvard Library, The British Library, among others. But I’ve only been able to try it with Google Arts and Culture and its vast collection.