Resizing image in Android

Question

I use the following method to resize images on Android.

public Bitmap resize(Bitmap img, int Width, int Height) {

    int width = img.getWidth();     
    int height = img.getHeight();
    int newWidth = (int) Width;
    int newHeight = (int) Height;

    // calculate the scale - in this case = 0.4f
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;

    // createa matrix for the manipulation
    Matrix matrix = new Matrix();

    // resize the bit map
    matrix.postScale(scaleWidth, scaleHeight);

    // rotate the Bitmap
    //matrix.postRotate(45);

    // recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(img, 0, 0, width, height, matrix, true);

    return resizedBitmap;
}

It works fine on most Android devices. But on some devices the resized image is not displaying. How might I resolve this?

Sounds like you've made a good start! Could you be more precise about how the bitmap is/isn't showing: examples: is it being passed into an imageView, drawable, or being drawn directly onto a canvas? — Tom
– Tom, Commented Sep 2, 2013 at 14:12
what do you mean the image is not displaying? also, is the density of both bitmaps set to be the same? — android developer
– android developer, Commented Sep 2, 2013 at 14:12
The problem occurs for Sprite bitmap with 10 frames. The width and height of each frame is 30 percentage of screenWidth and screenHeight. i use the below code to paint the bitmap, Rect destRect = new Rect(x, y, x + spriteWidth, y + spriteHeight); canvas.drawBitmap(bitmap, sourceRect, destRect, paint); — user2740092
– user2740092, Commented Sep 3, 2013 at 7:04

Community · Accepted Answer · 2017-05-23 12:29:23Z

1

You may create a scaled bitmap with

Bitmap bitmap = Bitmap.createScaledBitmap(b, width, height, true);

Here, width and height you can provide according to the device's screen size for different devices, by reading screen sizes programmatically. Here is how you can read the screen size of a device programmatically.

edited May 23, 2017 at 12:29

CommunityBot

11 silver badge

answered Sep 2, 2013 at 15:49

user3513843

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1 Comment

user2740092 Over a year ago

I have no problem in getting the screenSize of the device.

Ridcully · Accepted Answer · 2013-09-02 15:02:37Z

0

Most likely, on "some devices" and depending on the requested width and height, there's not enough memory to create the resized bitmap. Check (in debugger) if the resizedBitmap is null when the image "is not displaying".

answered Sep 2, 2013 at 15:02

Ridcully

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1 Comment

user2740092 Over a year ago

image is not null after resize

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