Binary package “libtk-img-dev” in ubuntu xenial

Extended image format support for Tcl/Tk (development files)

 Img is a package to enhance Tk by providing support for various image
 formats such as XPM, GIF (transparency supported, but not LZW), PNG,
 JPEG, TIFF, and PostScript.
 .
 The libimg library can be loaded dynamically into Tcl/Tk scripts to
 provide the image handling functions.
 .
 This package includes Tcl stub libraries and headers, which are necessary
 to develop C-based extensions using Img.