remove blanks

src/main/java/stirling/software/SPDF/controller/api/other/BlankPageController.java

@@ -2,6 +2,7 @@ package stirling.software.SPDF.controller.api.other;
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.pdmodel.PDPage;
 import org.apache.pdfbox.pdmodel.PDPageTree;
+import org.apache.pdfbox.rendering.PDFRenderer;
 import org.apache.pdfbox.text.PDFTextStripper;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -10,38 +11,30 @@ import org.springframework.web.bind.annotation.RequestPart;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.multipart.MultipartFile;
 import stirling.software.SPDF.utils.ImageFinder;
+import stirling.software.SPDF.utils.ProcessExecutor;
+
+import java.awt.image.BufferedImage;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import javax.imageio.ImageIO;
+
 @RestController
 public class BlankPageController {
 
     @PostMapping(consumes = "multipart/form-data", value = "/remove-blanks")
-    public ResponseEntity<byte[]> removeBlankPages(@RequestPart(required = true, value = "fileInput") MultipartFile inputFile, @RequestPart(required = true, value = "processType") int processType) throws IOException, InterruptedException {
-        boolean removeNoText = false;
-        boolean removeNoTextOrImages = false;
-        
-        if(processType == 0) {
-        	removeNoText = true;
-        } else if (processType == 1) {
-        	removeNoTextOrImages = true;
-        } else if (processType == 2) {
-        	//run OCR 
-        	OCRController ocr = new OCRController();
-            ocr.processPdfWithOCR(inputFile, Arrays.asList("eng"), false, false, true, false, "type", "hocr", false);
-            
-        	removeNoText = true;
-        }
-
+    public ResponseEntity<byte[]> removeBlankPages(@RequestPart(required = true, value = "fileInput") MultipartFile inputFile) throws IOException, InterruptedException {
         try {
             PDDocument document = PDDocument.load(inputFile.getInputStream());
             PDPageTree pages = document.getDocumentCatalog().getPages();
             PDFTextStripper textStripper = new PDFTextStripper();
 
-            List<PDPage> pagesToKeep = new ArrayList<>();
+            List<Integer> pagesToKeepIndex = new ArrayList<>();
             int pageIndex = 0;
 
             for (PDPage page : pages) {
@@ -50,28 +43,40 @@ public class BlankPageController {
                 textStripper.setEndPage(pageIndex);
                 String pageText = textStripper.getText(document);
                 boolean hasText = !pageText.trim().isEmpty();
+                if (hasText) {
+                	pagesToKeepIndex.add(pageIndex);
+                	System.out.print("page " + pageIndex + " has text");
+                	continue;
+                }
                 boolean hasImages = hasImagesOnPage(page);
-
-                if (removeNoText && removeNoTextOrImages) {
-                    if (hasText || hasImages) {
-                        pagesToKeep.add(page);
-                    }
-                } else if (removeNoText) {
-                    if (hasText) {
-                        pagesToKeep.add(page);
-                    }
-                } else if (removeNoTextOrImages) {
-                    if (hasText && hasImages) {
-                        pagesToKeep.add(page);
-                    }
-                } else {
-                    pagesToKeep.add(page);
+                if (hasImages) {
+                	pagesToKeepIndex.add(pageIndex);
+                	System.out.print("page " + pageIndex + " has image");
+                    continue;
                 }
             }
-
+            System.out.print(pagesToKeepIndex.size());
             PDDocument outputDocument = new PDDocument();
-            for (PDPage page : pagesToKeep) {
-                outputDocument.addPage(page);
+            PDFRenderer pdfRenderer = new PDFRenderer(document);
+            for (Integer i : pagesToKeepIndex) {
+                // Create temp file to save the image
+                Path tempFile = Files.createTempFile("image_", ".png");
+
+                // Render image and save as temp file
+                BufferedImage image = pdfRenderer.renderImageWithDPI(i - 1, 300);
+                ImageIO.write(image, "png", tempFile.toFile());
+                
+                List<String> command = new ArrayList<>(Arrays.asList("python3", "/scripts/detect-blank-pages.py", tempFile.toString())); 
+
+                // Run CLI command
+                int returnCode = ProcessExecutor.getInstance(ProcessExecutor.Processes.PYTHON_OPENCV).runCommandWithOutputHandling(command);
+
+				//does contain data
+                if(returnCode ==0) {
+                	outputDocument.addPage(document.getPage(i - 1));
+                } else {
+                	System.out.print("Found blank page skipping, page #" + i);
+                }
             }
 
             ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

src/main/java/stirling/software/SPDF/controller/web/OtherWebController.java

@@ -95,4 +95,11 @@ public class OtherWebController {
         return "other/repair";
     }
     
+    @GetMapping("/remove-blanks")
+    @Hidden
+    public String removeBlanksForm(Model model) {
+        model.addAttribute("currentPage", "remove-blanks");
+        return "other/remove-blanks";
+    }
+    
 }