How Clarify handles screenshots taken on high-resolution monitors
This article explains how Clarify handles screenshots taken on high-resolution displays. Clarify considers an image to be high-resolution if captured on a Mac retina display or on a Windows computer that has the zoom set higher than 100%.
When Clarify captures an image on a high-resolution monitor it stores all of the available image data. For example, on a Mac retina display there is 4x as much data in a screenshot of a 300x300 square as there is on a traditional monitor. Clarify is basically capturing a 600x600 image but displaying it in a 300x300 area. The same goes for a Windows computer with the zoom set to 200%.
When Clarify exports these images the high-resolution version of the image is used in most cases.
How Clarify embeds image density (ppi) information in the images it exports
The PNG or JPEG files that Clarify exports will include the density information in the file metadata. The image density setting will use a base value * the scale of the image. The base value is usually determined by the operating system that Clarify is running on.
On OS X the base value is 72ppi. On Windows, the base value is 96ppi.
For example, for a screen shot taken on a Mac retina display (which uses a base ppi value of 72) the density metadata value would be set to 144ppi. This is because a retina display displays 2x more data than a normal display. A Windows installation (which uses a base ppi value of 96) with the zoom set to 150% would have the density metadata value set to 144ppi.
Note that this ppi information that is embedded in the file DOES NOT affect how much data is in the actual image. It merely tells an application that is opening the image file how to scale the image. Note that web browsers completely ignore the density information in the image file.
Exporting to HTML
The default behavior when exporting to HTML is to export all of the image data but display the image at the natural size. For the 300x300 example, a 600x600 image would be exported but the HTML would set the width and height of the image to 300x300. This way, your images will look crisp on other high-resolution monitors.
An HTML template can override this behavior by setting the hi_res_images property to false. When set to false, Clarify will export images at their natural size and will discard the high-resolution data. This will result in smaller image files that won't look as crisp on high-resolution monitors.
Exporting to PDF/Word
When Clarify exports images for PDF and Word export the high-resolution version of the image is used. Images exported for PDF output use a base value of 96 which is what the PDF exporter expects. This occurs on Mac as well as Windows.
Images exported for Word output will use the base value for the platform you are running Clarify on. 72ppi for Mac, 96ppi for Windows.