deleted file mode 100644
--- a/inst/testimio.m
+++ /dev/null
@@ -1,56 +0,0 @@
-## This program is public domain.
-
-## build image for image r/w tests
-x=linspace(-8,8,200);
-[xx,yy]=meshgrid(x,x);
-r=sqrt(xx.^2+yy.^2) + eps;
-map=colormap(hsv);
-A=sin(r)./r;
-minval = min(A(:));
-maxval = max(A(:));
-z = round ((A-minval)/(maxval - minval) * (rows(colormap) - 1)) + 1;
-Rw=Gw=Bw=z;
-Rw(:)=fix(255*map(z,1));
-Gw(:)=fix(255*map(z,2));
-Bw(:)=fix(255*map(z,3));
-Aw=fix(255*(1-r/max(r(:)))); ## Fade to nothing at the corners
-
-if exist("jpgwrite")
-  disp(">jpgwrite"); 
-  jpgwrite('test.jpg',Rw,Gw,Bw);
-  stats=stat("test.jpg");
-  assert(stats.size,6423);
-  disp(">jpgread");
-  im = jpgread('test.jpg');
-  Rr = im(:,:,1); Gr = im(:,:,2); Br = im(:,:,3);
-  assert(all(Rw(:)-double(Rr(:))<35));
-  assert(all(Gw(:)-double(Gr(:))<35));
-  assert(all(Bw(:)-double(Br(:))<35));
-  unlink('test.jpg');
-else
-  disp(">jpgread ... not available");
-  disp(">jpgwrite ... not available");
-endif
-
-if exist("pngwrite")
-  disp(">pngwrite"); 
-  pngwrite('test.png',Rw,Gw,Bw,Aw);
-  stats=stat("test.png");
-  assert(stats.size,24738);
-  disp(">pngread");
-  im = pngread('test.png');
-  Rr = im(:,:,1); Gr = im(:,:,2); Br = im(:,:,3);
-  assert(all(double(Rr(:))==Rw(:)));
-  assert(all(double(Gr(:))==Gw(:)));
-  assert(all(double(Br(:))==Bw(:)));
-  [im,Ar] = pngread('test.png');
-  Rr = im(:,:,1); Gr = im(:,:,2); Br = im(:,:,3);
-  assert(all(double(Rr(:))==Rw(:)));
-  assert(all(double(Gr(:))==Gw(:)));
-  assert(all(double(Br(:))==Bw(:)));
-  assert(all(double(Ar(:))==Aw(:)));
-  unlink('test.png');
-else
-  disp(">pngread ... not available");
-  disp(">pngwrite ... not available");
-endif

--- a/src/jpgwrite.cc
+++ b/src/jpgwrite.cc
@@ -219,3 +219,30 @@
    return retval;
 
 }
+
+%!test
+%! if exist("jpgwrite","file")
+%!   ## build test image for r/w tests
+%!   x=linspace(-8,8,200);
+%!   [xx,yy]=meshgrid(x,x);
+%!   r=sqrt(xx.^2+yy.^2) + eps;
+%!   map=colormap(hsv);
+%!   A=sin(r)./r;
+%!   minval = min(A(:));
+%!   maxval = max(A(:));
+%!   z = round ((A-minval)/(maxval - minval) * (rows(colormap) - 1)) + 1;
+%!   Rw=Gw=Bw=z;
+%!   Rw(:)=fix(255*map(z,1));
+%!   Gw(:)=fix(255*map(z,2));
+%!   Bw(:)=fix(255*map(z,3));
+%!   Aw=fix(255*(1-r/max(r(:)))); ## Fade to nothing at the corners
+%!   jpgwrite('test.jpg',Rw,Gw,Bw);
+%!   stats=stat("test.jpg");
+%!   assert(stats.size,6423);
+%!   im = jpgread('test.jpg');
+%!   Rr = im(:,:,1); Gr = im(:,:,2); Br = im(:,:,3);
+%!   assert(all(Rw(:)-double(Rr(:))<35));
+%!   assert(all(Gw(:)-double(Gr(:))<35));
+%!   assert(all(Bw(:)-double(Br(:))<35));
+%!   unlink('test.jpg');
+%! endif

--- a/src/pngwrite.cc
+++ b/src/pngwrite.cc
@@ -164,3 +164,36 @@
   png_destroy_write_struct(&png_ptr, &info_ptr);          
   fclose(fp); 
 }
+
+%!test
+%! if exist("jpgwrite","file")
+%!   ## build test image for r/w tests
+%!   x=linspace(-8,8,200);
+%!   [xx,yy]=meshgrid(x,x);
+%!   r=sqrt(xx.^2+yy.^2) + eps;
+%!   map=colormap(hsv);
+%!   A=sin(r)./r;
+%!   minval = min(A(:));
+%!   maxval = max(A(:));
+%!   z = round ((A-minval)/(maxval - minval) * (rows(colormap) - 1)) + 1;
+%!   Rw=Gw=Bw=z;
+%!   Rw(:)=fix(255*map(z,1));
+%!   Gw(:)=fix(255*map(z,2));
+%!   Bw(:)=fix(255*map(z,3));
+%!   Aw=fix(255*(1-r/max(r(:)))); ## Fade to nothing at the corners
+%!   pngwrite('test.png',Rw,Gw,Bw,Aw);
+%!   stats=stat("test.png");
+%!   assert(stats.size,24738);
+%!   im = pngread('test.png');
+%!   Rr = im(:,:,1); Gr = im(:,:,2); Br = im(:,:,3);
+%!   assert(all(double(Rr(:))==Rw(:)));
+%!   assert(all(double(Gr(:))==Gw(:)));
+%!   assert(all(double(Br(:))==Bw(:)));
+%!   [im,Ar] = pngread('test.png');
+%!   Rr = im(:,:,1); Gr = im(:,:,2); Br = im(:,:,3);
+%!   assert(all(double(Rr(:))==Rw(:)));
+%!   assert(all(double(Gr(:))==Gw(:)));
+%!   assert(all(double(Br(:))==Bw(:)));
+%!   assert(all(double(Ar(:))==Aw(:)));
+%!   unlink('test.png');
+%! endif