line art (#5052)

## Summary - introduce a shared line art conversion interface and proprietary ImageMagick-backed implementation - have the compress controller optionally autowire the enterprise service before running per-image line art processing - remove ImageMagick command details from core by delegating conversions through the proprietary service ## Testing - not run (not requested) ------ [Codex Task](https://chatgpt.com/codex/tasks/task_b_6928aecceaf083289a9269b1ca99307e) --------- Co-authored-by: James Brunton <[email protected]>
2026-07-16 19:33:11 +02:00 · 2025-12-15 11:14:10 +00:00
parent 33188815da
commit 5f72c05623
24 changed files with 445 additions and 75 deletions
@@ -0,0 +1,81 @@
+package stirling.software.proprietary.service;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+import javax.imageio.ImageIO;
+
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
+import org.springframework.stereotype.Service;
+
+import lombok.extern.slf4j.Slf4j;
+
+import stirling.software.common.service.LineArtConversionService;
+import stirling.software.common.util.ProcessExecutor;
+import stirling.software.common.util.ProcessExecutor.ProcessExecutorResult;
+
+@Slf4j
+@Service
+public class ImageMagickLineArtConversionService implements LineArtConversionService {
+
+    @Override
+    public PDImageXObject convertImageToLineArt(
+            PDDocument doc, PDImageXObject originalImage, double threshold, int edgeLevel)
+            throws IOException {
+
+        Path inputImage = Files.createTempFile("lineart_image_input_", ".png");
+        Path outputImage = Files.createTempFile("lineart_image_output_", ".tiff");
+
+        try {
+            ImageIO.write(originalImage.getImage(), "png", inputImage.toFile());
+
+            List<String> command = new ArrayList<>();
+            command.add("magick");
+            command.add(inputImage.toString());
+            command.add("-colorspace");
+            command.add("Gray");
+
+            // Edge-aware line art conversion using ImageMagick's built-in operators.
+            // -edge/-negate/-normalize are standard convert options (IM v6+/v7) that
+            // accentuate outlines before thresholding to a bilevel image.
+            command.add("-edge");
+            command.add(String.valueOf(edgeLevel));
+            command.add("-negate");
+            command.add("-normalize");
+
+            command.add("-type");
+            command.add("Bilevel");
+            command.add("-threshold");
+            command.add(String.format(Locale.ROOT, "%.1f%%", threshold));
+            command.add("-compress");
+            command.add("Group4");
+            command.add(outputImage.toString());
+
+            ProcessExecutorResult result =
+                    ProcessExecutor.getInstance(ProcessExecutor.Processes.IMAGEMAGICK)
+                            .runCommandWithOutputHandling(command);
+
+            if (result.getRc() != 0) {
+                log.warn(
+                        "ImageMagick line art conversion failed with return code: {}",
+                        result.getRc());
+                throw new IOException("ImageMagick line art conversion failed");
+            }
+
+            byte[] convertedBytes = Files.readAllBytes(outputImage);
+            return PDImageXObject.createFromByteArray(
+                    doc, convertedBytes, originalImage.getCOSObject().toString());
+        } catch (Exception e) {
+            log.warn("ImageMagick line art conversion failed", e);
+            throw new IOException("ImageMagick line art conversion failed", e);
+        } finally {
+            Files.deleteIfExists(inputImage);
+            Files.deleteIfExists(outputImage);
+        }
+    }
+}