save image file with bitmap factory

Question

I'm encountering an issue with bitmap factory. I've got a method to reduce and rotate an image to show a preview in an image view, but I would like to save this with the new size. I'm just turning around with inputfilestream and outputfilestream but don't get to save it. Is anybody know a clear method to put my bitmap in an outpufilestream? Thanks a lot here's my code

@Override
protected void onResume() {
    super.onResume();
    File[] fileArray;
    final File root;
    File chemin = Environment.getExternalStorageDirectory();
    String filepath = chemin + "/SmartCollecte/PARC/OUT/" + fichano + "_" + conteneur_s+"_"+cpt+".jpg";


    try {
        decodeFile(filepath);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }}


public void decodeFile(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 = 1024;

    // 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 b1 = BitmapFactory.decodeFile(filePath, o2);
    Bitmap b = ExifUtils.rotateBitmap(filePath, b1);
    FileOutputStream fos = new FileOutputStream(filePath);
    b.compress(Bitmap.CompressFormat.PNG,100,fos);
    fos.close();
    showImg.setImageBitmap(b);


}

Possible duplicate of [How to save a bitmap on internal storage](https://stackoverflow.com/questions/15662258/how-to-save-a-bitmap-on-internal-storage) — hossam scott, Nov 13 '18 at 09:21

Mikhail Olshanski · Answer 1 · 2018-10-23T09:14:50.340

0

Have you tried doing it like this? Assuming bitmap is bitmap you want to save.

Also, take a look at some existing system directories.

final FileOutputStream fos = new FileOutputStream(new File(filepath + "_scaled.jpg"));
try {
    bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos);
} catch (IOException e) {
    // handle exception
} finally {
    fos.close
}

Source

Where first parameter of Bitmap.compress() is your desired output format (see CompressFormat) and the second parameter is compression quality.

edited Oct 23 '18 at 09:14

answered Oct 18 '18 at 15:34

Mikhail Olshanski

760
8
16

Thanks Mikhail but my image is in JPG.Should I try this? – filoman Oct 22 '18 at 14:06
@filoman sure, you'll just have to pass format appropriate for you like JPEG. Second parameter is quality, you can choose whatever suits you. Sorry about confusion. – Mikhail Olshanski Oct 22 '18 at 14:12
I already tried that but got a null object reference error on it. Seems like the file outputstream is empty – filoman Oct 23 '18 at 08:54
@filoman, can you show the code, please? How do you initialize it? I'll edit my answer to make it more clear. – Mikhail Olshanski Oct 23 '18 at 09:01
Can't seem to find where you write bitmap to the file. Can you please add it to your post and maybe provide the stacktrace? – Mikhail Olshanski Oct 24 '18 at 06:05
Sorry it disappeared! I put it again. Itried with JPEG too – filoman Oct 24 '18 at 09:39

score 0 · Answer 2 · answered Nov 13 '18 at 08:34

ok I found out what was missing. had to create a new byte array to convert my bitmap to file :

String filepathcomp = Environment.getExternalStorageDirectory()+"/SmartCollecte/PARC/OUT/"+ fichano + "_" + conteneur_s+"_"+cpt+".jpg";
    File f = new File(filepathcomp);
    Bitmap newbitmap = b;
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    newbitmap.compress(Bitmap.CompressFormat.JPEG,80,bos);
    byte[] bitmapdata = bos.toByteArray();
    FileOutputStream fos = new FileOutputStream(f);
    fos.write(bitmapdata);
    fos.flush();
    fos.close();

save image file with bitmap factory

2 Answers2