gnu: Add img2pdf.

* gnu/packages/pdf.scm (img2pdf): New variable.

gnu/packages/pdf.scm

@@ -93,6 +93,7 @@ (define-module (gnu packages pdf)
   #:use-module (gnu packages sqlite)
   #:use-module (gnu packages tex)
   #:use-module (gnu packages time)
+  #:use-module (gnu packages tcl)
   #:use-module (gnu packages tls)
   #:use-module (gnu packages web)
   #:use-module (gnu packages xdisorg)
@@ -1082,6 +1083,29 @@ (define-public impressive
 the PDF pages.")
     (license license:gpl2)))
 
+(define-public img2pdf
+  (package
+    (name "img2pdf")
+    (version "0.4.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (pypi-uri "img2pdf" version))
+       (sha256
+        (base32 "1jdhmpzgj8815bhargb3xp3ydlqxwkz0mcadrflx2ga0p056kvpa"))))
+    (build-system python-build-system)
+    (propagated-inputs
+     `(("python-pikepdf" ,python-pikepdf)
+       ("python-pillow" ,python-pillow)
+       ("python-tkinter" ,python "tk")))
+    (home-page "https://gitlab.mister-muffin.de/josch/img2pdf")
+    (synopsis "Convert images to PDF via direct JPEG inclusion")
+    (description
+     "img2pdf converts images to PDF via direct JPEG inclusion.  That
+conversion is lossless: the image embedded in the PDF has the exact same color
+information for every pixel as the input.")
+    (license license:lgpl3)))
+
 (define-public fbida
   (package
     (name "fbida")