Fix img2pdf 0.2 usage

All tests pass when forced to rely on img2pdf, so seems okay

ocrmypdf/main.py

@@ -165,9 +165,6 @@ parser.add_argument(
     '--skip-big', type=float, metavar='MPixels',
     help="skip OCR on pages larger than the specified amount of megapixels, "
          "but include skipped pages in final output")
-# parser.add_argument(
-#     '--exact-image', action='store_true',
-#     help="Use original page from PDF without re-rendering")
 
 advanced = parser.add_argument_group(
     "Advanced",
@@ -594,12 +591,15 @@ def select_image_layer(
         pageinfo = get_pageinfo(image, pdfinfo, pdfinfo_lock)
         dpi = round(max(pageinfo['xres'], pageinfo['yres'],
                         options.oversample))
-        imgsize = '{0}dpix{1}dpi'.format(dpi, dpi)
+        imgsize = ((img2pdf.ImgSize.dpi, dpi), (img2pdf.ImgSize.dpi, dpi))
+
         layout_fun = img2pdf.get_layout_fun(None, imgsize, None, None, None)
 
-        with open(output_file, 'wb') as pdf:
+        with open(image, 'rb') as imfile, \
+                open(output_file, 'wb') as pdf:
+            rawdata = imfile.read()
             pdf.write(img2pdf.convert(
-                [image], producer="img2pdf", with_pdfrw=False,
+                rawdata, producer="img2pdf", with_pdfrw=False,
                 layout_fun=layout_fun))