How to put image to PDF using iText without losing image quality?

Question

I am using this code:

Bitmap itemImage = reduceImageAtFilePathFromGallery(imageName);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
itemImage.compress(Bitmap.CompressFormat.PNG, 100, stream);

imageAnswer = Image.getInstance(stream.toByteArray());

---

private Bitmap reduceImageAtFilePathFromGallery(String filePath) {
    // Decode image size 
    BitmapFactory.Options o = new BitmapFactory.Options(); 
    o.inJustDecodeBounds = true; 
    BitmapFactory.decodeFile(filePath, o); 

    // The new size we want to scale to 
    final int REQUIRED_SIZE = 256; 

    // Find the correct scale value. It should be the power of 2. 
    int width_tmp = o.outWidth, height_tmp = o.outHeight; 
    int scale = 1; 
    while (true) { 
        if (width_tmp < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE) 
            break; 
        width_tmp /= 2; 
        height_tmp /= 2; 
        scale *= 2; 
    } 

    // Decode with inSampleSize 
    BitmapFactory.Options o2 = new BitmapFactory.Options(); 
    o2.inSampleSize = scale; 
    Bitmap bitmap = BitmapFactory.decodeFile(filePath, o2); 
    return bitmap;
}

But the image's quality becomes bad. Then, I also tried below code:

Image imageAnswer = getAndResizeImage(imageName);

---

private Image getAndResizeImage(String imageFilename){
    final File imageFile = new File(imageFilename);
    if (imageFile.exists()) {
        Bitmap b = null;
        try {
            File f = new File(imageFilename);
            b = BitmapFactory.decodeFile(f.getAbsolutePath());

            //calculate how many bytes our image consists of.
            int bytes = getSizeInBytes(b);

            ByteBuffer buffer = ByteBuffer.allocate(bytes); //Create a new buffer
            b.copyPixelsToBuffer(buffer); //Move the byte data to the buffer

            byte[] array = buffer.array(); //Get the underlying array containing the data.
            Image image = Image.getInstance(array);

            return image;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
    }

    return null;
}

and it gives this error:

09-09 15:08:58.368: W/S

ystem.err(1385): java.io.IOException: The byte array is not a recognized imageformat. 09-09 15:08:58.378: W/System.err(1385): at com.itextpdf.text.Image.getInstance(Image.java:442) 09-09

on this line of code:

Image image = Image.getInstance(array);

Is there any way I can have good quality of image on PDF using iText?

Answer 1

使用JPEG压缩格式而不是PNG

itemImage.compress(Bitmap.CompressFormat.JPEG, 100, stream);