ocrolib: ensure closing FDs after mkstemp and PIL.Image.open

Author: Robert Sachunsky

ocrd_cis/ocropy/common.py

@@ -402,6 +402,7 @@ def DSAVE(title,array, interactive=False):
     from matplotlib import cm
     from matplotlib import patches as mpatches
     from tempfile import mkstemp
+    from os import close
     # set uniformly bright / maximally differentiating colors
     cmap = cm.rainbow # default viridis is too dark on low end
     # use black for bg (not in the cmap)
@@ -440,8 +441,9 @@ def on_press(event):
         plt.disconnect('key_press_event')
         return result
     else:
-        _,fname = mkstemp(suffix=title+".png")
+        fd, fname = mkstemp(suffix=title+".png")
         plt.imsave(fname,array,vmin=vmin,vmax=vmax,cmap=cmap)
+        close(fd)
         LOG.debug('DSAVE %s', fname)
 
 @checks(ABINARY2,NUMBER)

ocrd_cis/ocropy/ocrolib/common.py

@@ -165,8 +165,8 @@ def read_image_gray(fname,pageno=0):
     the range 0...1 (unsigned) or -1...1 (signed)."""
     if type(fname)==tuple: fname,pageno = fname
     assert pageno==0
-    pil = PIL.Image.open(fname)
-    a = pil2array(pil)
+    with PIL.Image.open(fname) as pil:
+        a = pil2array(pil)
     if a.dtype==dtype('uint8'):
         a = a/255.0
     if a.dtype==dtype('int8'):
@@ -202,8 +202,8 @@ def read_image_binary(fname,dtype='i',pageno=0):
     of the given dtype."""
     if type(fname)==tuple: fname,pageno = fname
     assert pageno==0
-    pil = PIL.Image.open(fname)
-    a = pil2array(pil)
+    with PIL.Image.open(fname) as pil:
+        a = pil2array(pil)
     if a.ndim==3: a = amax(a,axis=2)
     return array(a>0.5*(amin(a)+amax(a)),dtype)
 
@@ -256,8 +256,8 @@ def make_seg_white(image):
 def read_line_segmentation(fname):
     """Reads a line segmentation, that is an RGB image whose values
     encode the segmentation of a text line.  Returns an int array."""
-    pil = PIL.Image.open(fname)
-    a = pil2array(pil)
+    with PIL.Image.open(fname) as pil:
+        a = pil2array(pil)
     assert a.dtype==dtype('B')
     assert a.ndim==3
     image = rgb2int(a)
@@ -276,8 +276,8 @@ def write_line_segmentation(fname,image):
 def read_page_segmentation(fname):
     """Reads a page segmentation, that is an RGB image whose values
     encode the segmentation of a page.  Returns an int array."""
-    pil = PIL.Image.open(fname)
-    a = pil2array(pil)
+    with PIL.Image.open(fname) as pil:
+        a = pil2array(pil)
     assert a.dtype==dtype('B')
     assert a.ndim==3
     segmentation = rgb2int(a)