A PJPG file is a raster image saved in the Progressive JPEG format. It contains encoded bitmap data that enables the image to render in multiple scans from a blurry picture to a sharp image as it is downloaded. PJPG files allow image viewing programs to show previews before the final image data is received.

The Progressive JPEG format was used by some older Web browsers, such as older versions of Microsoft Internet Explorer. However, now the format is rarely used and supported since communication links are becoming much faster. You can convert the PJPG image to a .JPG image by renaming the ".pjpg" extension to ".jpg" then opening it in a program that supports JPG images, such as Microsoft Photos in Windows or Apple Preview in macOS. You can view the image then export it to a format, such as JPEG or PNG, that is more widely supported.