HPG is a vector image format created in a standard programming language called HPGL (Hewlett-Packard graphics language). Other extensions created in this language include PLT, HP2 and PL2. All are called "plotter files" and are created by drawing programs such as AutoCAD to be printed using a device specialized in vector graphics. An HPG file uses a line series of two-letter codes to render an image and can also include parameters.
JPEG JPG PNG GIF TIFF TIF BMP ICO EMF WMF AI PDF EPS PS EPI WEBP WEBPLL JP2 PCX TGA DWG DWF DXF DGN WMZ CGM DRW GBR PCT MIF PLT PCL SVG WPG CIN DCX DIS HRU MTV PRC RAD PIC RLA QRT SGI XBM XPM SWF CAL PSD JXR BPG APNG DDS SVGZ CG4 FLIF