How to Resize Image (Bitmap) to a Given Size

How to resize image (Bitmap) to a given size?

Bitmap scaledBitmap = scaleDown(realImage, MAX_IMAGE_SIZE, true);

Scale down method:

public static Bitmap scaleDown(Bitmap realImage, float maxImageSize,
        boolean filter) {
    float ratio = Math.min(
            (float) maxImageSize / realImage.getWidth(),
            (float) maxImageSize / realImage.getHeight());
    int width = Math.round((float) ratio * realImage.getWidth());
    int height = Math.round((float) ratio * realImage.getHeight());

    Bitmap newBitmap = Bitmap.createScaledBitmap(realImage, width,
            height, filter);
    return newBitmap;
}

How to Resize a Bitmap in Android?

Change:

profileImage.setImageBitmap(
    BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length)

To:

Bitmap b = BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length)
profileImage.setImageBitmap(Bitmap.createScaledBitmap(b, 120, 120, false));

Scale bitmap to specific size, keeping aspect ratio and filling the rest with 0 alpha pixels

I managed to solve it using this function:

Bitmap resizeBitmap(Bitmap image, int destWidth, int destHeight) {
    Bitmap background = Bitmap.createBitmap(destWidth, destHeight, Bitmap.Config.ARGB_8888);
    float originalWidth = image.getWidth();
    float originalHeight = image.getHeight();
    Canvas canvas = new Canvas(background);

    float scaleX = (float) 1280 / originalWidth;
    float scaleY = (float) 720 / originalHeight;

    float xTranslation = 0.0f;
    float yTranslation = 0.0f;
    float scale = 1;

    if (scaleX < scaleY) { // Scale on X, translate on Y
        scale = scaleX;
        yTranslation = (destHeight - originalHeight * scale) / 2.0f;
    } else { // Scale on Y, translate on X
        scale = scaleY;
        xTranslation = (destWidth - originalWidth * scale) / 2.0f;
    }

    Matrix transformation = new Matrix();
    transformation.postTranslate(xTranslation, yTranslation);
    transformation.preScale(scale, scale);
    Paint paint = new Paint();
    paint.setFilterBitmap(true);
    canvas.drawBitmap(image, transformation, paint);
    return background;
}

Scaling a System.Drawing.Bitmap to a given size while maintaining aspect ratio

Target parameters:

float width = 1024;
float height = 768;
var brush = new SolidBrush(Color.Black);

Your original file:

var image = new Bitmap(file);

Target sizing (scale factor):

float scale = Math.Min(width / image.Width, height / image.Height);

The resize including brushing canvas first:

var bmp = new Bitmap((int)width, (int)height);
var graph = Graphics.FromImage(bmp);

// uncomment for higher quality output
//graph.InterpolationMode = InterpolationMode.High;
//graph.CompositingQuality = CompositingQuality.HighQuality;
//graph.SmoothingMode = SmoothingMode.AntiAlias;

var scaleWidth = (int)(image.Width * scale);
var scaleHeight = (int)(image.Height * scale);

graph.FillRectangle(brush, new RectangleF(0, 0, width, height));
graph.DrawImage(image, ((int)width - scaleWidth)/2, ((int)height - scaleHeight)/2, scaleWidth, scaleHeight);

And don't forget to do a bmp.Save(filename) to save the resulting file.

How do I resize an image to fill the new dimensions?

Although none of the answers worked for me, I appreciate all the help and suggestions on which I could get to a solution pretty fast, here is the piece of code that worked for me:

private Bitmap resizeImage(Image image, int width, int height, float HorizontalResolution, float VerticalResolution)
{
    Rectangle destRect = new Rectangle(0, 0, width, height);
    Bitmap destImage = new Bitmap(width, height);

    destImage.SetResolution(HorizontalResolution, VerticalResolution);

    using (var graphics = Graphics.FromImage(destImage))
    {
         graphics.CompositingQuality = CompositingQuality.HighQuality;
         graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
         graphics.SmoothingMode = SmoothingMode.HighQuality;
         graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;

         //drawImage must be set this way to get the desired outcome
         graphics.DrawImage(imageBox.Image, new Rectangle(0, 0, image.Width, image.Height), destRect, GraphicsUnit.Pixel);
    }

    return destImage;
}

Basically I removed the wrapMode code and changed my drawImage method.

How to resize a bitmap image : Android

Yes you can do this by using the following code snippets, the first section retrns the width and height of the current screen, the second section re-sizes the image.

// This will return the screen size in pixels
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;

// Use this to bind and re-size the image
Bitmap car;
car = BitmapFactory.decodeResource(getResources(), R.drawable.car);
car = Bitmap.createScaledBitmap(car, width, height, true);

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