Merge branch 'main' into calRGB

pypdf/filters.py

@@ -641,7 +641,9 @@ def decodeStreamData(stream: Any) -> Union[str, bytes]: # deprecated
  return decode_stream_data(stream)
 
 
-mode_str_type: TypeAlias = Literal["", "1", "RGB", "P", "L", "RGBA", "CMYK"]
+mode_str_type: TypeAlias = Literal[
+ "", "1", "RGB", "2bits", "4bits", "P", "L", "RGBA", "CMYK"
+]
 
 
 def _get_imagemode(
@@ -675,6 +677,8 @@ def _get_imagemode(
 
  mode_map = {
  "1bit": "1", # 0 will be used for 1 bit
+ "2bit": "2bits", # 2 bits images
+ "4bit": "4bits", # 4 bits
  "/DeviceGray": "L",
  "palette": "P", # reserved for color_components alignment
  "/DeviceRGB": "RGB",
@@ -720,6 +724,24 @@ def _handle_flate(
  Process image encoded in flateEncode
  Returns img, image_format, extension
  """
+
+ def bits2byte(data: bytes, size: Tuple[int, int], bits: int) -> bytes:
+ mask = (2 << bits) - 1
+ nbuff = bytearray(size[0] * size[1])
+ by = 0
+ bit = 8 - bits
+ for y in range(size[1]):
+ if (bit != 0) and (bit != 8 - bits):
+ by += 1
+ bit = 8 - bits
+ for x in range(size[0]):
+ nbuff[y * size[0] + x] = (data[by] >> bit) & mask
+ bit -= bits
+ if bit < 0:
+ by += 1
+ bit = 8 - bits
+ return bytes(nbuff)
+
  extension = ".png" # mime_type = "image/png"
  lookup: Any
  base: Any
@@ -728,6 +750,12 @@ def _handle_flate(
  color_space, base, hival, lookup = (
  value.get_object() for value in color_space
  )
+ if mode == "2bits":
+ mode = "P"
+ data = bits2byte(data, size, 2)
+ elif mode == "4bits":
+ mode = "P"
+ data = bits2byte(data, size, 4)
  img = Image.frombytes(mode, size, data)
  if color_space == "/Indexed":
  from .generic import ByteStringObject
@@ -822,8 +850,8 @@ def _handle_jpx(
  ):
  # https://pillow.readthedocs.io/en/stable/handbook/concepts.html#modes
  mode: mode_str_type = "RGB"
- if x_object_obj.get("/BitsPerComponent", 8) == 1:
- mode = _get_imagemode("1bit", 0, "")
+ if x_object_obj.get("/BitsPerComponent", 8) < 8:
+ mode = _get_imagemode(f"{x_object_obj.get('/BitsPerComponent', 8)}bit", 0, "")
  else:
  mode = _get_imagemode(
  color_space,
@@ -844,7 +872,11 @@ def _handle_jpx(
  lfilters = filters[-1] if isinstance(filters, list) else filters
  if lfilters == FT.FLATE_DECODE:
  img, image_format, extension = _handle_flate(
- size, data, mode, color_space, colors
+ size,
+ data,
+ mode,
+ color_space,
+ colors,
  )
  elif lfilters in (FT.LZW_DECODE, FT.ASCII_85_DECODE, FT.CCITT_FAX_DECODE):
  # I'm not sure if the following logic is correct.
@@ -900,14 +932,6 @@ def _handle_jpx(
  # TODO : implement mask
  if alpha.mode != "L":
  alpha = alpha.convert("L")
- scale = x_object_obj[IA.S_MASK].get("/Decode", [0.0, 1.0])
- if (scale[1] - scale[0]) != 1.0:
- alpha = alpha.point(
- [
- round(255.0 * (v / 255.0 * (scale[1] - scale[0]) + scale[0]))
- for v in range(256)
- ]
- )
  if img.mode == "P":
  img = img.convert("RGB")
  img.putalpha(alpha)

tests/test_filters.py

@@ -446,3 +446,22 @@ def test_calrgb():
  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"""
+ url = "https://github.com/py-pdf/pypdf/files/12050253/tt.pdf"
+ name = "paid.pdf"
+ reader = PdfReader(BytesIO(get_pdf_from_url(url, name=name)))
+ url_png = "https://user-images.githubusercontent.com/4083478/253568117-ca95cc85-9dea-4145-a5e0-032f1c1aa322.png"
+ name_png = "Paid.png"
+ refimg = Image.open(
+ BytesIO(get_pdf_from_url(url_png, name=name_png))
+ ) # not a pdf but it works
+ data = reader.pages[0].images[0]
+ diff = ImageChops.difference(data.image, refimg)
+ d = sqrt(
+ sum([(a * a + b * b + c * c + d * d) for a, b, c, d in diff.getdata()])
+ ) / (diff.size[0] * diff.size[1])
+ assert d < 0.01