wmjordan/PDFPatcher · error · InvalidOperationException

合并图片失败：粘贴操作出错

Error message

合并图片失败：粘贴操作出错

What it means

ImageExtractor's PasteAndIncrementHeight throws InvalidOperationException when FreeImageBitmap.Paste returns false, indicating the paste of a source bitmap into the composite _Image at the current _Height offset failed. Paste can fail on dimension mismatches, format incompatibilities, or internal FreeImage errors.

Source

Thrown at App/Processor/ImageExtractor.cs:722

					: ColorType.IndexedColor;
			}

			void PasteIntoFullColor(FreeImageBitmap bmp) {
				if (bmp.HasPalette) {
					TryExpandColorDepth(bmp);
				}
				PasteAndIncrementHeight(bmp);
			}

			static void TryExpandColorDepth(FreeImageBitmap bmp) {
				if (!bmp.ConvertColorDepth(FREE_IMAGE_COLOR_DEPTH.FICD_24_BPP)) {
					throw new InvalidOperationException("合并图片失败：无法转换图片颜色");
				}
			}

			void PasteAndIncrementHeight(FreeImageBitmap bmp) {
				if (!_Image.Paste(bmp, 0, _Height, Int32.MaxValue)) {
					throw new InvalidOperationException("合并图片失败：粘贴操作出错");
				}
				_Height += bmp.Height;
			}

			void ExpandColorSpaceAndPaste(FreeImageBitmap bmp) {
				TryExpandColorDepth(_Image);
				PasteIntoFullColor(bmp);
			}
		}

		enum ColorType
		{
			Undefined,
			BlackAndWhite,
			WhiteAndBlack,
			IndexedColor,
			FullColor,
		}

View on GitHub (pinned to 4782bbd9ad)

Solutions

1. Ensure the composite and source share the same color depth (call TryExpandColorDepth first) before pasting.
2. Verify the source bitmap width matches the composite width before attempting paste.
3. Catch the exception and fall back to exporting images individually rather than merging.
4. Update the FreeImage native library and check for corrupt source images.

Example fix

// before
void PasteAndIncrementHeight(FreeImageBitmap bmp) {
  if (!_Image.Paste(bmp, 0, _Height, Int32.MaxValue))
    throw new InvalidOperationException("合并图片失败：粘贴操作出错");
  _Height += bmp.Height;
}

// after
void PasteAndIncrementHeight(FreeImageBitmap bmp) {
  if (bmp.Width != _Image.Width || !_Image.Paste(bmp, 0, _Height, Int32.MaxValue)) {
    Tracker.TraceMessage(Tracker.Category.Warning, "粘贴失败，改为单独导出。");
    ExportSeparately(bmp);
    return;
  }
  _Height += bmp.Height;
}

if (bmp.Width != _Image.Width) { ExportSeparately(bmp); return; }
// also ensure matching color depth before paste

static bool CanPasteInto(FreeImageBitmap target, FreeImageBitmap src) =>
    target.Width == src.Width && target.ColorDepth == src.ColorDepth;

try { PasteAndIncrementHeight(bmp); }
catch (InvalidOperationException) { ExportSeparately(bmp); }

When it happens

Trigger: Calling the merge paste path with a bitmap whose dimensions/format are incompatible with the target composite, or when the composite _Image is in a state (e.g. wrong color depth) that rejects the paste. The guard treats the boolean Paste return as success/failure.

Common situations: Merging extracted PDF images where one image has a different bit depth or palette than the composite built so far; a width mismatch between the source and composite; memory pressure causing the native paste to fail; a corrupted extracted image.

Related errors

• 合并图片失败：无法转换图片颜色
• File is not a valid JPEG
• Could not find Exif data block
• Exif data not found
• Malformed Exif data

AI-assisted analysis of wmjordan/PDFPatcher@4782bbd9ad (2026-08-13). Data as JSON: /api/errors/4275f7bd32a0c5fb. Report an issue: GitHub.