Issue1632 remove images (#1645)

* Implemented PdfImageRemovalService.java and PdfImageRemovalController.java. Image can be removed testing using Postman, but the file size doesn't change.

* Fix removal logic in service file to decrease file size.

* Implement "Remove Image" feature on the website

Updated the front-end code to integrate the "Remove Image" feature. The new functionality is now fully operational on the website, allowing users to remove images as expected.

* Add comments to PdfImageRemovalController and PdfImageRemovalService.

* Change the google material icon in navbar, homepage and remove-image-pdf.html.

src/main/java/stirling/software/SPDF/service/PdfImageRemovalService.java

@@ -0,0 +1,43 @@
+package stirling.software.SPDF.service;
+
+import java.io.IOException;
+
+import org.apache.pdfbox.cos.COSName;
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDResources;
+import org.apache.pdfbox.pdmodel.graphics.PDXObject;
+import org.springframework.stereotype.Service;
+
+/**
+ * Service class responsible for removing image objects from a PDF document.
+ */
+@Service
+public class PdfImageRemovalService {
+
+    /**
+     * Removes all image objects from the provided PDF document.
+     *
+     * This method iterates over each page in the document and removes any
+     * image XObjects found in the page's resources.
+     *
+     * @param document The PDF document from which images will be removed.
+     * @return The modified PDF document with images removed.
+     * @throws IOException If an error occurs while processing the PDF document.
+     */
+    public PDDocument removeImagesFromPdf(PDDocument document) throws IOException {
+        // Iterate over each page in the PDF document
+        for (PDPage page : document.getPages()) {
+            PDResources resources = page.getResources();
+            // Iterate over all XObject names in the page's resources
+            for (COSName name : resources.getXObjectNames()) {
+                // Check if the XObject is an image
+                if (resources.isImageXObject(name)) {
+                    // Remove the image XObject by setting it to null
+                    resources.put(name, (PDXObject) null);
+                }
+            }
+        }
+        return document;
+    }
+}