+ (ly:format
+ "~a \"~a\" | ~a -reduce ~a | ~a -compression 9 > \"~a\""
+ (search-pngtopam) tmp1-name
+ (search-pamscale) factor
+ (search-pnmtopng)
+ tmp2-name)))
+
+ (close-port port-tmp1)
+ (close-port port-tmp2)
+ (ly:debug (_ "Copying `~a' to `~a'...") file tmp1-name)
+ (copy-binary-file file tmp1-name)
+ (ly:system-with-shell cmd)
+ (ly:debug (_ "Copying `~a' to `~a'...") tmp2-name file)
+ (copy-binary-file tmp2-name file)
+ (ly:debug (_ "Deleting `~a'...") tmp1-name)
+ (delete-file tmp1-name)
+ (ly:debug (_ "Deleting `~a'...") tmp2-name)
+ (delete-file tmp2-name)))