Tests/LibGfx: Add JBIG2 tests for refinement regions refining the page

The decode ok in Preview.app, Acrobat Reader, poppler, and HEAD PDFium.

Author: nico

Tests/LibGfx/TestImageDecoder.cpp

@@ -366,6 +366,8 @@ TEST_CASE(test_jbig2_decode)
         TEST_INPUT("jbig2/bitmap-trailing-7fff-stripped-harder.jbig2"sv),
         TEST_INPUT("jbig2/bitmap-trailing-7fff-stripped-harder-refine.jbig2"sv),
         TEST_INPUT("jbig2/bitmap-refine.jbig2"sv),
+        TEST_INPUT("jbig2/bitmap-refine-page.jbig2"sv),
+        TEST_INPUT("jbig2/bitmap-refine-page-subrect.jbig2"sv),
         TEST_INPUT("jbig2/bitmap-refine-customat.jbig2"sv),
         TEST_INPUT("jbig2/bitmap-refine-lossless.jbig2"sv),
         TEST_INPUT("jbig2/bitmap-refine-refine.jbig2"sv),
@@ -420,7 +422,6 @@ TEST_CASE(test_jbig2_decode)
         // - intermediate direct regions (code support added in #26197)
         // - symbol refinement referring to symbol in same segment
         // Missing tests for things that aren't implemented yet:
-        // - immediate refinement regions not referring to a direct region (i.e. refining the page)
         // - exttemplate
         // - colors
     };

Tests/LibGfx/test-inputs/jbig2/bitmap-refine-page-subrect.jbig2

@@ -0,0 +1,60 @@
+{
+    "global_header": {
+        "organization": "sequential",
+        "number_of_pages": 1
+    },
+    "segments": [
+        {
+            "segment_number": 0,
+            "type": "page_information",
+            "page_association": 1,
+            "data": {
+                "page_width": 399,
+                "page_height": 400,
+                "flags": {
+                    "direct_region_segments_override_default_combination_operator": true
+                }
+            }
+        },
+        {
+            "segment_number": 1,
+            "type": "generic_region",
+            "page_association": 1,
+            "data": {
+                "image_data": {
+                    "from_file": "bitmap-blemish.bmp"
+                }
+            }
+        },
+        {
+            "segment_number": 2,
+            "type": "generic_refinement_region",
+            "page_association": 1,
+            "data": {
+                "region_segment_information": {
+                    "x": 10,
+                    "y": 20,
+                    "width": 110,
+                    "height": 380,
+                    "flags": {
+                        "external_combination_operator": "replace"
+                    }
+                },
+                "image_data": {
+                    "from_file": "bitmap.bmp",
+                    "crop": {
+                        "x": 10,
+                        "y": 20,
+                        "width": 110,
+                        "height": 380
+                    }
+                }
+            }
+        },
+        {
+            "segment_number": 3,
+            "type": "end_of_page",
+            "page_association": 1
+        }
+    ]
+}

Tests/LibGfx/test-inputs/jbig2/bitmap-refine-page.jbig2

@@ -0,0 +1,50 @@
+{
+    "global_header": {
+        "organization": "sequential",
+        "number_of_pages": 1
+    },
+    "segments": [
+        {
+            "segment_number": 0,
+            "type": "page_information",
+            "page_association": 1,
+            "data": {
+                "page_width": 399,
+                "page_height": 400,
+                "flags": {
+                    "direct_region_segments_override_default_combination_operator": true
+                }
+            }
+        },
+        {
+            "segment_number": 1,
+            "type": "generic_region",
+            "page_association": 1,
+            "data": {
+                "image_data": {
+                    "from_file": "bitmap-blemish.bmp"
+                }
+            }
+        },
+        {
+            "segment_number": 2,
+            "type": "generic_refinement_region",
+            "page_association": 1,
+            "data": {
+                "region_segment_information": {
+                    "flags": {
+                        "external_combination_operator": "replace"
+                    }
+                },
+                "image_data": {
+                    "from_file": "bitmap.bmp"
+                }
+            }
+        },
+        {
+            "segment_number": 3,
+            "type": "end_of_page",
+            "page_association": 1
+        }
+    ]
+}