Add cmyk support (#756)

Author: devdev29

CHANGELOG.md

@@ -18,6 +18,7 @@ This can also be enabled programmatically with `warnings.simplefilter('default',
 
 ## [2.7.4] - Not released yet
 ### Added
+- [`FPDF.image()`](https://pyfpdf.github.io/fpdf2/fpdf/fpdf.html#fpdf.fpdf.FPDF.image): CMYK images can now be inserted directly by passing them into the image method. Contributed by @devdev29
 - documentation on how to embed `graphs` and `charts` generated using `Pygal` lib: [documentation section](https://pyfpdf.github.io/fpdf2/Maths.html#using-pygal) - thanks to @ssavi-ict
 - documentation on how to use `fpdf2` with [FastAPI](https://fastapi.tiangolo.com/): <https://pyfpdf.github.io/fpdf2/UsageInWebAPI.html#FastAPI> - thanks to @KamarulAdha
 - [`FPDF.write_html()`](https://pyfpdf.github.io/fpdf2/fpdf/fpdf.html#fpdf.fpdf.FPDF.write_html): `<table>` elements can now be aligned left or right on the page using `align=`

fpdf/image_parsing.py

@@ -115,6 +115,7 @@ def get_img_info(filename, img=None, image_filter="AUTO", dims=None):
         raise EnvironmentError("Pillow not available - fpdf2 cannot insert images")
 
     is_pil_img = True
+    jpeg_inverted = False  # flag to check whether a cmyk image is jpeg or not, if set to True the decode array is inverted in output.py
     img_raw_data = None
     if not img or isinstance(img, (Path, str)):
         img_raw_data = load_image(filename)
@@ -146,7 +147,7 @@ def get_img_info(filename, img=None, image_filter="AUTO", dims=None):
     if img.mode in ("P", "PA") and image_filter != "FlateDecode":
         img = img.convert("RGBA")
 
-    if img.mode not in ("1", "L", "LA", "RGB", "RGBA", "P", "PA"):
+    if img.mode not in ("1", "L", "LA", "RGB", "RGBA", "P", "PA", "CMYK"):
         img = img.convert("RGBA")
         img_altered = True
 
@@ -161,7 +162,11 @@ def get_img_info(filename, img=None, image_filter="AUTO", dims=None):
     if img_raw_data is not None and not img_altered:
         # if we can use the original image bytes directly we do (JPEG and group4 TIFF only):
         if img.format == "JPEG" and image_filter == "DCTDecode":
-            dpn, bpc, colspace = 3, 8, "DeviceRGB"
+            if img.mode in ("RGB", "RGBA"):
+                dpn, bpc, colspace = 3, 8, "DeviceRGB"
+            elif img.mode == "CMYK":
+                dpn, bpc, colspace = 4, 8, "DeviceCMYK"
+                jpeg_inverted = True
             if img.mode == "L":
                 dpn, bpc, colspace = 1, 8, "DeviceGray"
             img_raw_data.seek(0)
@@ -174,6 +179,7 @@ def get_img_info(filename, img=None, image_filter="AUTO", dims=None):
                 "dpn": dpn,
                 "bpc": bpc,
                 "f": image_filter,
+                "inverted": jpeg_inverted,
                 "dp": f"/Predictor 15 /Colors {dpn} /Columns {w}",
             }
         # We can directly copy the data out of a CCITT Group 4 encoded TIFF, if it
@@ -218,6 +224,7 @@ def get_img_info(filename, img=None, image_filter="AUTO", dims=None):
                 "cs": colspace,
                 "bpc": bpc,
                 "f": image_filter,
+                "inverted": jpeg_inverted,
                 "dp": f"/BlackIs1 {str(not inverted).lower()} /Columns {w} /K -1 /Rows {h}",
             }
 
@@ -263,6 +270,9 @@ def get_img_info(filename, img=None, image_filter="AUTO", dims=None):
             "JPXDecode",
         ):
             info["smask"] = _to_data(img, image_filter, select_slice=alpha_channel)
+    elif img.mode == "CMYK":
+        dpn, bpc, colspace = 4, 8, "DeviceCMYK"
+        info["data"] = _to_data(img, image_filter)
     elif img.mode == "RGB":
         dpn, bpc, colspace = 3, 8, "DeviceRGB"
         info["data"] = _to_data(img, image_filter)
@@ -293,6 +303,7 @@ def get_img_info(filename, img=None, image_filter="AUTO", dims=None):
             "bpc": bpc,
             "dpn": dpn,
             "f": image_filter,
+            "inverted": jpeg_inverted,
             "dp": dp,
         }
     )

fpdf/output.py

@@ -766,10 +766,8 @@ def _add_image(self, info):
             iccp_pdf_i = self._ensure_iccp(info)
             color_space = PDFArray(["/ICCBased", str(iccp_pdf_i), str("0"), "R"])
         elif color_space == "DeviceCMYK":
-            decode = "[1 0 1 0 1 0 1 0]"
-            raise NotImplementedError(
-                "fpdf2 does not support DeviceCMYK ColorSpace yet - cf. issue #711"
-            )
+            if info["inverted"] is True:
+                decode = "[1 0 1 0 1 0 1 0]"
 
         decode_parms = f"<<{info['dp']} /BitsPerComponent {info['bpc']}>>"
         img_obj = PDFXObject(

test/image/image_types/image_types_insert_tiff_cmyk.pdf

@@ -50,6 +50,14 @@ def test_insert_jpg_flatedecode(tmp_path):
         assert_pdf_equal(pdf, HERE / "image_types_insert_jpg_flatedecode.pdf", tmp_path)
 
 
+def test_insert_jpg_cmyk(tmp_path):
+    pdf = fpdf.FPDF()
+    pdf.compress = False
+    pdf.add_page()
+    pdf.image(HERE / "insert_images_insert_jpg_cmyk.jpg", x=15, y=15)
+    assert_pdf_equal(pdf, HERE / "images_types_insert_jpg_cmyk.pdf", tmp_path)
+
+
 def test_insert_png(tmp_path):
     pdf = fpdf.FPDF()
     pdf.add_page()
@@ -168,6 +176,13 @@ def test_insert_g4_tiff(tmp_path):
     assert_pdf_equal(pdf, HERE / "image_types_insert_tiff.pdf", tmp_path)
 
 
+def test_insert_tiff_cmyk(tmp_path):
+    pdf = fpdf.FPDF()
+    pdf.add_page()
+    pdf.image(HERE / "insert_images_insert_tiff_cmyk.tiff", x=15, y=15)
+    assert_pdf_equal(pdf, HERE / "image_types_insert_tiff_cmyk.pdf", tmp_path)
+
+
 def test_insert_pillow(tmp_path):
     pdf = fpdf.FPDF()
     pdf.add_page()