NXPowerLite also converts many other image types to JPEG where appropriate.
NXPowerLite converts bi-level (black and white) images to lossless JBIG2 encoding, which typically generates files one third to one fifth the size of CCITT Group 4 encoding. PDF files allow a wide range of inefficient image formats to be stored inside them natively. NXPowerLite can scale these images down to target a particular resolution for display or print. For example, a photograph taken by a digital camera might contain five million or more pixels, but most of this detail will not be visible unless 'zoom' controls are used. Images are often inserted into PDF files at much larger sizes than necessary. For this type of file NXPowerLite ignores the text and focuses on resizing and choosing the best format for the embedded images. PDF files generated from an electronic source - such as a Word document, a computer generated report, or spreadsheet data - will usually be formed of a combination of text and images. By reducing the resolution of these images and choosing an efficient image encoding these files can be dramatically reduced. So even documents that appear to be just text can often be entirely images. Scanners often capture document pages as high resolution images without compression.
NXPowerLite is able to reduce the size of both types of PDF by resizing images, adjusting image formats and quality levels while removing background or hidden data that isn't needed for normal use of the file. PDF files are most often scanned physical documents or documents that have been created entirely digitally often referred to as 'native' or 'born digital' PDFs.