Image on canvas to JPEG file

Question

I'm drawing 2D images on the canvas.

I want to save image shown on canvas to JPEG file, how can I do it?

Since the link you referred to is long since dead could you perhaps add a bit more context into the question itself? — Flexo, May 22 '15 at 14:49

score 29 · Accepted Answer · answered Feb 01 '10 at 06:50

create an empty bitmap
create a new Canvas object and pass this bitmap to it
call view.draw(Canvas) passing it the canvas object you just created. Refer Documentation of method for details.
Use Bitmap.compress() to write the contents of the bitmap to an OutputStream, file maybe.

Pseudo code:

Bitmap  bitmap = Bitmap.createBitmap( view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
view.draw(canvas); 
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos);

Hello Samuh, I tried the code, it generates a jpeg file but does not have the canvas drawn shape or what ever I have written on canvas. Any comment. Thanks, Ketan — , Feb 09 '11 at 09:50

score 12 · Answer 2 · answered Aug 19 '11 at 10:39

set Drawing Cache Enabled
Draw whatever you want
Get Bitmap object from view
Compress and save the image file


import java.io.File;
import java.io.FileOutputStream;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

public class CanvasTest extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Draw2d d = new Draw2d(this);
        setContentView(d);
    }

    public class Draw2d extends View {

        public Draw2d(Context context) {
            super(context);
            setDrawingCacheEnabled(true);
        }

        @Override
        protected void onDraw(Canvas c) {
            Paint paint = new Paint();
            paint.setColor(Color.RED);          
            c.drawCircle(50, 50, 30, paint);

            try {
                getDrawingCache().compress(Bitmap.CompressFormat.JPEG, 100, new FileOutputStream(new File("/mnt/sdcard/arun.jpg")));
            } catch (Exception e) {
                Log.e("Error--------->", e.toString());
            }
            super.onDraw(c);
        }

    }

}

Somehow it feels like a bad idea to compress and save within the onDraw method. — Simon Forsberg, Jun 23 '13 at 18:10

score 6 · Answer 3 · answered Mar 07 '12 at 11:14

Canvas to JPG:

Canvas canvas = null;
FileOutputStream fos = null;
Bitmap bmpBase = null;

bmpBase = Bitmap.createBitmap(image_width, image_height, Bitmap.Config.ARGB_8888);
canvas = new Canvas(bmpBase);
// draw what ever you want canvas.draw...

// Save Bitmap to File
try
{
    fos = new FileOutputStream(your_path);
    bmpBase.compress(Bitmap.CompressFormat.PNG, 100, fos);

    fos.flush();
    fos.close();
    fos = null;
}
catch (IOException e)
{
    e.printStackTrace();
}
finally
{
    if (fos != null)
    {
        try
        {
            fos.close();
            fos = null;
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }
}

Image on canvas to JPEG file

3 Answers3

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