Pick image from sd card, resize the image and save it back to sd card

Question

I am working on an application, in which I need to pick an image from sd card and show it in image view. Now I want the user to decrease/increase its width by clicking a button and then save it back to the sd card.

I have done the image picking and showing it on ui. But unable to find how to resize it.Can anyone please suggest me how to achieve it.

Answer 1

Just yesterday i have done this

File dir=Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM); Bitmap b= BitmapFactory.decodeFile(PATH_ORIGINAL_IMAGE); Bitmap out = Bitmap.createScaledBitmap(b, 320, 480, false);  File file = new File(dir, "resize.png"); FileOutputStream fOut; try {     fOut = new FileOutputStream(file);     out.compress(Bitmap.CompressFormat.PNG, 100, fOut);     fOut.flush();     fOut.close();     b.recycle();     out.recycle();                } catch (Exception e) {} 

Also don't forget to recycle your bitmaps: It will save memory.

You can also get path of new created file String: newPath=file.getAbsolutePath();

Answer 2

Solution without OutOfMemoryException in Kotlin

fun resizeImage(file: File, scaleTo: Int = 1024) {
    val bmOptions = BitmapFactory.Options()
    bmOptions.inJustDecodeBounds = true
    BitmapFactory.decodeFile(file.absolutePath, bmOptions)
    val photoW = bmOptions.outWidth
    val photoH = bmOptions.outHeight

    // Determine how much to scale down the image
    val scaleFactor = Math.min(photoW / scaleTo, photoH / scaleTo)

    bmOptions.inJustDecodeBounds = false
    bmOptions.inSampleSize = scaleFactor

    val resized = BitmapFactory.decodeFile(file.absolutePath, bmOptions) ?: return
    file.outputStream().use {
        resized.compress(Bitmap.CompressFormat.JPEG, 75, it)
        resized.recycle()
    }
}

Answer 3

Try using this method:

public static Bitmap scaleBitmap(Bitmap bitmapToScale, float newWidth, float newHeight) {   
if(bitmapToScale == null)
    return null;
//get the original width and height
int width = bitmapToScale.getWidth();
int height = bitmapToScale.getHeight();
// create a matrix for the manipulation
Matrix matrix = new Matrix();

// resize the bit map
matrix.postScale(newWidth / width, newHeight / height);

// recreate the new Bitmap and set it back
return Bitmap.createBitmap(bitmapToScale, 0, 0, bitmapToScale.getWidth(), bitmapToScale.getHeight(), matrix, true);  
}