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https://github.com/Frooodle/Stirling-PDF.git
synced 2025-09-12 17:52:13 +02:00
Compression fix
This commit is contained in:
Anthony Stirling
parent
0fb76a1f4c
commit
853744864b
@ -25,7 +25,7 @@ ext {
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}
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group = "stirling.software"
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version = "0.44.2"
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version = "0.44.3"
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java {
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// 17 is lowest but we support and recommend 21
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@ -25,12 +25,23 @@ import javax.imageio.ImageWriter;
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import javax.imageio.plugins.jpeg.JPEGImageWriteParam;
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import javax.imageio.stream.ImageOutputStream;
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import org.apache.pdfbox.contentstream.PDFStreamEngine;
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import org.apache.pdfbox.contentstream.operator.Operator;
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import org.apache.pdfbox.cos.COSArray;
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import org.apache.pdfbox.cos.COSBase;
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import org.apache.pdfbox.cos.COSDictionary;
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import org.apache.pdfbox.cos.COSName;
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import org.apache.pdfbox.cos.COSStream;
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import org.apache.pdfbox.pdmodel.PDDocument;
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import org.apache.pdfbox.pdmodel.PDDocumentCatalog;
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import org.apache.pdfbox.pdmodel.PDPage;
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import org.apache.pdfbox.pdmodel.PDResources;
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import org.apache.pdfbox.pdmodel.graphics.PDXObject;
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import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;
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import org.apache.pdfbox.pdmodel.graphics.image.PDInlineImage;
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import org.apache.pdfbox.pdmodel.graphics.pattern.PDAbstractPattern;
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import org.apache.pdfbox.pdmodel.graphics.pattern.PDTilingPattern;
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import org.apache.pdfbox.pdmodel.graphics.shading.PDShading;
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import org.springframework.beans.factory.annotation.Autowired;
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import org.springframework.http.ResponseEntity;
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import org.springframework.web.bind.annotation.ModelAttribute;
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@ -78,11 +89,19 @@ public class CompressController {
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int pageNum; // Page number where the image appears
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COSName name; // The name used to reference this image
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}
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@Data
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@AllArgsConstructor
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@NoArgsConstructor
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private static class NestedImageReference extends ImageReference {
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COSName formName; // Name of the form XObject containing the image
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COSName imageName; // Name of the image within the form
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}
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public Path compressImagesInPDF(
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Path pdfFile, double scaleFactor, float jpegQuality, boolean convertToGrayscale)
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throws Exception {
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Path newCompressedPDF = Files.createTempFile("compressedPDF", ".pdf");
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Path newCompressedPDF = Files.createTempFile("compressedPDF", ".pdf");
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long originalFileSize = Files.size(pdfFile);
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log.info(
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"Starting image compression with scale factor: {}, JPEG quality: {}, grayscale: {} on file size: {}",
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@ -92,42 +111,84 @@ public class CompressController {
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GeneralUtils.formatBytes(originalFileSize));
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try (PDDocument doc = pdfDocumentFactory.load(pdfFile)) {
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// Collect all unique images by content hash
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Map<String, List<ImageReference>> uniqueImages = new HashMap<>();
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Map<String, PDImageXObject> compressedVersions = new HashMap<>();
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int totalImages = 0;
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int nestedImages = 0;
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// FIRST PASS: Collect all images (direct and nested)
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for (int pageNum = 0; pageNum < doc.getNumberOfPages(); pageNum++) {
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PDPage page = doc.getPage(pageNum);
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PDResources res = page.getResources();
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if (res == null || res.getXObjectNames() == null) continue;
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// Process direct XObjects on page
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for (COSName name : res.getXObjectNames()) {
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PDXObject xobj = res.getXObject(name);
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if (!(xobj instanceof PDImageXObject)) continue;
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totalImages++;
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PDImageXObject image = (PDImageXObject) xobj;
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String imageHash = generateImageHash(image);
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// Direct image
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if (xobj instanceof PDImageXObject) {
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totalImages++;
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PDImageXObject image = (PDImageXObject) xobj;
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String imageHash = generateImageHash(image);
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// Store only page number and name reference
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ImageReference ref = new ImageReference();
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ref.pageNum = pageNum;
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ref.name = name;
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ImageReference ref = new ImageReference();
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ref.pageNum = pageNum;
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ref.name = name;
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uniqueImages.computeIfAbsent(imageHash, k -> new ArrayList<>()).add(ref);
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log.info("Found direct image '{}' on page {} - {}x{}",
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name.getName(), pageNum + 1, image.getWidth(), image.getHeight());
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uniqueImages.computeIfAbsent(imageHash, k -> new ArrayList<>()).add(ref);
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}
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// Form XObject may contain nested images
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else if (xobj instanceof org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject) {
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org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject formXObj =
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(org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject) xobj;
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PDResources formResources = formXObj.getResources();
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if (formResources != null && formResources.getXObjectNames() != null) {
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// Process nested XObjects within the form
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log.info("Checking form XObject '{}' on page {} for nested images",
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name.getName(), pageNum + 1);
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for (COSName nestedName : formResources.getXObjectNames()) {
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PDXObject nestedXobj = formResources.getXObject(nestedName);
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if (nestedXobj instanceof PDImageXObject) {
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nestedImages++;
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totalImages++;
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PDImageXObject nestedImage = (PDImageXObject) nestedXobj;
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log.info("Found nested image '{}' in form '{}' on page {} - {}x{}",
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nestedName.getName(), name.getName(), pageNum + 1,
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nestedImage.getWidth(), nestedImage.getHeight());
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// Create a specialized reference for the nested image
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NestedImageReference nestedRef = new NestedImageReference();
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nestedRef.pageNum = pageNum;
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nestedRef.formName = name;
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nestedRef.imageName = nestedName;
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String imageHash = generateImageHash(nestedImage);
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uniqueImages.computeIfAbsent(imageHash, k -> new ArrayList<>()).add(nestedRef);
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}
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}
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}
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}
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}
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}
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int uniqueImagesCount = uniqueImages.size();
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int duplicatedImages = totalImages - uniqueImagesCount;
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log.info(
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"Found {} unique images and {} duplicated instances across {} pages",
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"Found {} unique images and {} duplicated instances across {} pages ({} nested images in form XObjects)",
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uniqueImagesCount,
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duplicatedImages,
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doc.getNumberOfPages());
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doc.getNumberOfPages(),
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nestedImages);
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// SECOND PASS: Process each unique image exactly once
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int compressedImages = 0;
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@ -143,10 +204,33 @@ public class CompressController {
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// Get the first instance of this image
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ImageReference firstRef = references.get(0);
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PDPage firstPage = doc.getPage(firstRef.pageNum);
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PDResources firstPageResources = firstPage.getResources();
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PDImageXObject originalImage =
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(PDImageXObject) firstPageResources.getXObject(firstRef.name);
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PDImageXObject originalImage;
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// Handle differently based on whether it's a direct or nested image
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if (firstRef instanceof NestedImageReference) {
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// Get the nested image from within a form XObject
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NestedImageReference nestedRef = (NestedImageReference) firstRef;
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PDPage firstPage = doc.getPage(nestedRef.pageNum);
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PDResources pageResources = firstPage.getResources();
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// Get the form XObject
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org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject formXObj =
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(org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject) pageResources.getXObject(nestedRef.formName);
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// Get the nested image from the form's resources
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PDResources formResources = formXObj.getResources();
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originalImage = (PDImageXObject) formResources.getXObject(nestedRef.imageName);
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log.info("Processing nested image '{}' from form '{}'",
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nestedRef.imageName.getName(), nestedRef.formName.getName());
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} else {
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// Get direct image from page resources
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PDPage firstPage = doc.getPage(firstRef.pageNum);
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PDResources firstPageResources = firstPage.getResources();
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originalImage = (PDImageXObject) firstPageResources.getXObject(firstRef.name);
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log.debug("Processing direct image '{}'", firstRef.name.getName());
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}
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// Track original size
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int originalSize = (int) originalImage.getCOSObject().getLength();
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@ -185,14 +269,36 @@ public class CompressController {
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// Replace ALL instances with the compressed version
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for (ImageReference ref : references) {
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// Get the page and resources when needed
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PDPage page = doc.getPage(ref.pageNum);
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PDResources resources = page.getResources();
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resources.put(ref.name, compressedImage);
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if (ref instanceof NestedImageReference) {
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// Replace nested image within form XObject
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NestedImageReference nestedRef = (NestedImageReference) ref;
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PDPage page = doc.getPage(nestedRef.pageNum);
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PDResources pageResources = page.getResources();
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log.info(
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"Replaced image on page {} with compressed version",
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ref.pageNum + 1);
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// Get the form XObject
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org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject formXObj =
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(org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject)
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pageResources.getXObject(nestedRef.formName);
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// Replace the nested image in the form's resources
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PDResources formResources = formXObj.getResources();
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formResources.put(nestedRef.imageName, compressedImage);
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log.info(
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"Replaced nested image '{}' in form '{}' on page {} with compressed version",
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nestedRef.imageName.getName(),
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nestedRef.formName.getName(),
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nestedRef.pageNum + 1);
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} else {
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// Replace direct image in page resources
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PDPage page = doc.getPage(ref.pageNum);
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PDResources resources = page.getResources();
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resources.put(ref.name, compressedImage);
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log.info(
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"Replaced direct image on page {} with compressed version",
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ref.pageNum + 1);
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}
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}
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totalCompressedBytes += compressedData.length * references.size();
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@ -216,11 +322,12 @@ public class CompressController {
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: 0;
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log.info(
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"Image compression summary - Total unique: {}, Compressed: {}, Skipped: {}, Duplicates: {}",
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"Image compression summary - Total unique: {}, Compressed: {}, Skipped: {}, Duplicates: {}, Nested: {}",
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uniqueImagesCount,
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compressedImages,
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skippedImages,
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duplicatedImages);
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duplicatedImages,
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nestedImages);
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log.info(
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"Total original image size: {}, compressed: {} (reduced by {}%)",
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GeneralUtils.formatBytes(totalOriginalBytes),
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@ -245,7 +352,6 @@ public class CompressController {
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String.format("%.1f", overallReduction));
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return newCompressedPDF;
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}
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}
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private BufferedImage convertToGrayscale(BufferedImage image) {
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@ -611,7 +717,7 @@ public class CompressController {
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// Check if optimized file is larger than the original
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long finalFileSize = Files.size(currentFile);
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if (finalFileSize > inputFileSize) {
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if (finalFileSize >= inputFileSize) {
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log.warn("Optimized file is larger than the original. Using the original file instead.");
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// Use the stored reference to the original file
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currentFile = originalFile;
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