Merge images

Aspose.PDF 21.4 allows you to combine Images. Merge Images method checks the contents of a specific folder and works with the specified type of files in it. When working with merging pictures, we specify ‘inputImagesStreams’, Image Format and Image Merge Mode (as example - vertical) of our file. Then we save our result in FileOutputStream.

Follow the next code snippet for resolve your task:

Merge Images

 public static void MergeImages01() {
        File f = new File(_dataDir);
        File[] images = f.listFiles((dir, name) -> name.toLowerCase().endsWith(".jpg"));
        ArrayList<InputStream> inputImagesStreams = new ArrayList<InputStream>();
        for (File image : images) {
            try {
                inputImagesStreams.add(new FileInputStream(image));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }

        InputStream inputStream = PdfConverter.mergeImages(inputImagesStreams, com.aspose.pdf.ImageFormat.Jpeg,
                ImageMergeMode.Vertical, 1, 1);
        try {
            inputStream.transferTo(new FileOutputStream(_dataDir + "merged_images.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

The second example works the same as the previous one, but the merged images will be saved horizontally.

   public static void MergeImages02() {
        File f = new File(_dataDir);
        File[] images = f.listFiles((dir, name) ->  name.toLowerCase().endsWith(".jpg"));
        ArrayList<InputStream> inputImagesStreams = new ArrayList<InputStream>();
        for (File image : images) {
            try {
                inputImagesStreams.add(new FileInputStream(image));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }

        InputStream inputStream = PdfConverter.mergeImages(
            inputImagesStreams, 
            com.aspose.pdf.ImageFormat.Jpeg,
            ImageMergeMode.Horizontal, 1, 1);
        try {
            inputStream.transferTo(new FileOutputStream(_dataDir + "merged_images.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

In the third example, we will merge the pictures by centering them. Two horizontally, two vertically.

 public static void MergeImages03() {
        File f = new File(_dataDir);
        File[] images = f.listFiles((dir, name) -> name.toLowerCase().endsWith(".jpg"));
        ArrayList<InputStream> inputImagesStreams = new ArrayList<InputStream>();
        for (File image : images) {
            try {
                inputImagesStreams.add(new FileInputStream(image));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }

        InputStream inputStream = PdfConverter.mergeImages(inputImagesStreams, com.aspose.pdf.ImageFormat.Jpeg,
                ImageMergeMode.Center, 2, 2);
        try {
            inputStream.transferTo(new FileOutputStream(_dataDir + "merged_images.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

Also, Aspose.PDF for Java present you the opportunity to combine pictures and save them in the Tiff format, using MergeImagesAsTiff Method.

   public static void MergeImages04() {
        File f = new File(_dataDir);
        File[] images = f.listFiles((dir, name) -> name.toLowerCase().endsWith(".jpg"));
        ArrayList<InputStream> inputImagesStreams = new ArrayList<InputStream>();
        for (File image : images) {
            try {
                inputImagesStreams.add(new FileInputStream(image));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }

        InputStream inputStream = PdfConverter.mergeImagesAsTiff(inputImagesStreams);
        try {
            inputStream.transferTo(new FileOutputStream(_dataDir + "merged_images.jpg"));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

To save the merged images as one image on PDF page, we place them in the imageStream, place the result on the page with addImage method, where we specify the coordinates where we want to place them.

    public static void MergeImages05()
    {
        File f = new File(_dataDir);
        File[] images = f.listFiles((dir, name) -> name.toLowerCase().endsWith(".jpg"));
        ArrayList<InputStream> inputImagesStreams = new ArrayList<InputStream>();
        for (File image : images) {
            try {
                inputImagesStreams.add(new FileInputStream(image));
            } catch (FileNotFoundException e) {                
                e.printStackTrace();
            }
        }

        InputStream imageStream = PdfConverter.mergeImages(inputImagesStreams, com.aspose.pdf.ImageFormat.Jpeg,
                ImageMergeMode.Vertical, 1, 1);
        
        Document document = new Document();
        Page page=document.getPages().add();
        page.addImage(imageStream, new Rectangle(10,120,400,720));
    }