display huge Images in Android

Question

I'm intending to display very large Images in Android.

My first solution - to supply them as pdf - fails because not every handheld got a pdf-viewer preinstalled, and I don't want to require the users to install one.

So I have a png now (width = 3998px height=2827px) that I want to display. I downloaded this image to test how it would be displayed the gallery. It was quite painful. It seems that the galery renders this picture only once, and if I Zoom in, I cannot read the text at all.

So I wrote a testActivity which simply has an ImageView nested in a LinearLayout. I put the image into the drawable and set it as ImageView's image-source. Unforunately the app crashes immediatly, due to an "

 ERROR/AndroidRuntime(8906): Caused by: java.lang.OutOfMemoryError: bitmap size exceeds VM budget"  

I didn't expect that ONE single Image can be too large forVM's memory. I played a little bit around, set ImageViews size to 3998 & 2827px , put the Image to sdCard and read it manually with a fileInputStream.
To my big surprise it now shows my image, but if I turn my Nexus S horizontal I get the same OutOfMemoryError as before.

Can somewone point me the main difference between recieving a Bitmap through a FileInputStream or to set it as ImageView's source.

Also I'm not able to scroll comfortable with two parent scrollViews

I searching for a simple solution to display ONE large image at a time with the ability to scroll horizontal and vertical while able to zoom in and out.

here is a sample of the image I want to display

Answer 1

I know it's an old post but I spent a lot of time on this problem, so here's my solution.

I wanted to display a 2000×3000 picture but I got out of memory or the image was too large to be displayed.

To begin, I get the dimensions of the picture:

o = new BitmapFactory.Options();
o.inJustDecodeBounds=true;
pictures = BitmapFactory.decodeStream(new FileInputStream(f), null, o);

Then I cut it up into four parts and displayed them with four ImageViews. I tried to load the full picture and cut it into four (using BitmapFactory.create(bitmap,int,int,int,int)) but got out of memory again.

So I decided to use some BitMapRegionDecoder:

for (int i = 0; i < 2; i++) {
    for (int j = 0; j < 2; j++) {
        ImageView iv = new ImageView(this);         
        InputStream istream =   null;
        try {
         istream = this.getContentResolver().openInputStream(Uri.fromFile(f));
        } catch (FileNotFoundException e1) {
         e1.printStackTrace();
        }
        BitmapRegionDecoder decoder     =   null;
        try {
        decoder = BitmapRegionDecoder.newInstance(istream, false);
        } catch (IOException e) {
                    e.printStackTrace();
        }
    int nw = (j*width/k);
    int nh = (i*height/k);

    Bitmap bMap = decoder.decodeRegion(new Rect(nw,nh, (nw+width/k),(nh+height/k)), null);    
    iv.setImageBitmap(bMap);

    }
}

This worked.