BUG: Accept calRGB and calGray color_spaces (#1968)

Fixes #1956

Author: pubpub-zz

pypdf/filters.py

@@ -656,6 +656,8 @@ def _get_imagemode(
         raise PdfReadError(
             "can not interprete colorspace", color_space
         )  # pragma: no cover
+    elif color_space[0].startswith("/Cal"):  # /CalRGB and /CalGray
+        color_space = "/Device" + color_space[0][4:]
     elif color_space[0] == "/ICCBased":
         icc_profile = color_space[1].get_object()
         color_components = cast(int, icc_profile["/N"])

tests/test_filters.py

@@ -440,6 +440,14 @@ def test_cascaded_filters_images():
             _ = i.name, i.image
 
 
+@pytest.mark.enable_socket()
+def test_calrgb():
+    url = "https://github.com/py-pdf/pypdf/files/12061061/tt.pdf"
+    name = "calRGB.pdf"
+    reader = PdfReader(BytesIO(get_pdf_from_url(url, name=name)))
+    reader.pages[0].images[0]
+
+
 @pytest.mark.enable_socket()
 def test_2bits_image():
     """From #1954, test with 2bits image. TODO: 4bits also"""