@@ -455,7 +455,7 @@ def test_nonuniformimage_setnorm():
455455
456456@knownfailureif (not HAS_PIL )
457457@cleanup
458- def test_jpeg_alpha ():
458+ def test_flatten ():
459459plt .figure (figsize = (1 ,1 ),dpi = 300 )
460460# Create an image that is all black, with a gradient from 0-1 in
461461# the alpha channel from left to right.
@@ -464,21 +464,43 @@ def test_jpeg_alpha():
464464
465465plt .figimage (im )
466466
467- buff = io .BytesIO ()
467+ jpg_buf = io .BytesIO ()
468+ pngF_buf = io .BytesIO ()
469+ png_buf = io .BytesIO ()
470+
468471with rc_context ({'savefig.facecolor' :'red' }):
469- plt .savefig (buff ,transparent = True ,format = 'jpg' ,dpi = 300 )
472+ plt .savefig (jpg_buf ,transparent = True ,format = 'jpg' ,dpi = 300 )
473+ plt .savefig (pngF_buf ,transparent = True ,format = 'png' ,
474+ flatten = True ,dpi = 300 )
475+ plt .savefig (png_buf ,transparent = True ,format = 'png' ,dpi = 300 )
470476
471- buff .seek (0 )
472- image = Image .open (buff )
477+ jpg_buf .seek (0 )
478+ pngF_buf .seek (0 )
479+ png_buf .seek (0 )
480+
481+ jpg_im = Image .open (jpg_buf )
482+ pngF_im = Image .open (pngF_buf )
483+ png_im = Image .open (png_buf )
473484
474485# If this fails, there will be only one color (all black). If this
475486# is working, we should have all 256 shades of grey represented.
476- print ("num colors: " ,len (image .getcolors (256 )))
477- assert len (image .getcolors (256 ))>= 175 and len (image .getcolors (256 ))<= 185
487+ print ("num colors [jpg]: " ,len (jpg_im .getcolors (256 )))
488+ print ("num colors [png, flattened]: " ,len (pngF_im .getcolors (256 )))
489+ print ("num colors [png, not flattened]: " ,len (pngF_im .getcolors (256 )))
490+
491+ assert len (jpg_im .getcolors (256 ))>= 175 and len (jpg_im .getcolors (256 ))<= 185
492+ assert len (pngF_im .getcolor (256 ))== 256
493+ assert len (png_im .getcolor (256 ))== 256
494+
478495# The fully transparent part should be red, not white or black
479- # or anything else
480- print ("corner pixel: " ,image .getpixel ((0 ,0 )))
481- assert image .getpixel ((0 ,0 ))== (254 ,0 ,0 )
496+ # or anything else when flattened.
497+ print ("corner pixel [jpg]: " ,jpg_im .getpixel ((0 ,0 )))
498+ print ("corner pixel [png, flattened]: " ,pngF_im .getpixel ((0 ,0 )))
499+ print ("corner pixel [png, not flattened]: " ,png_im .getpixel ((0 ,0 )))
500+
501+ assert jpg_im .getpixel ((0 ,0 ))== (254 ,0 ,0 )
502+ assert pngF_im .getpixel ((0 ,0 ))== (255 ,0 ,0 ,255 )
503+ assert png_im .getpixel ((0 ,0 ))== (255 ,255 ,255 ,0 )
482504
483505
484506if __name__ == '__main__' :