Come ridimensionare l'immagine su Android?

Sto creando un'applicazione e desidero impostare una visualizzazione galleria. Non voglio che le immagini nella vista galleria siano a grandezza naturale. Come ridimensiono le immagini su Android?

Provare:

Bitmap yourBitmap;
Bitmap resized = Bitmap.createScaledBitmap(yourBitmap, newWidth, newHeight, true);

o:

resized = Bitmap.createScaledBitmap(yourBitmap,(int)(yourBitmap.getWidth()*0.8), (int)(yourBitmap.getHeight()*0.8), true);

public Bitmap resizeBitmap(String photoPath, int targetW, int targetH) {
    BitmapFactory.Options bmOptions = new BitmapFactory.Options();
    bmOptions.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(photoPath, bmOptions);
    int photoW = bmOptions.outWidth;
    int photoH = bmOptions.outHeight;

    int scaleFactor = 1;
    if ((targetW > 0) || (targetH > 0)) {
            scaleFactor = Math.min(photoW/targetW, photoH/targetH);        
    }

    bmOptions.inJustDecodeBounds = false;
    bmOptions.inSampleSize = scaleFactor;
    bmOptions.inPurgeable = true; //Deprecated API 21

    return BitmapFactory.decodeFile(photoPath, bmOptions);            
}

Cattura l'immagine e ridimensionala.

Bitmap image2 = (Bitmap) data.getExtras().get("data");
img.setImageBitmap(image2);
String incident_ID = IncidentFormActivity.incident_id;

imagepath="/sdcard/RDMS/"+incident_ID+ x + ".PNG";
File file = new File(imagepath);
    try {
        double xFactor = 0;
        double width = Double.valueOf(image2.getWidth());
        Log.v("WIDTH", String.valueOf(width));
        double height = Double.valueOf(image2.getHeight());
        Log.v("height", String.valueOf(height));
        if(width>height){
        xFactor = 841/width;
    }
    else{
        xFactor = 595/width;
    }


Log.v("Nheight", String.valueOf(width*xFactor));
Log.v("Nweight", String.valueOf(height*xFactor));
int Nheight = (int) ((xFactor*height));
int NWidth =(int) (xFactor * width) ; 

bm = Bitmap.createScaledBitmap( image2,NWidth, Nheight, true);
file.createNewFile();
FileOutputStream ostream = new FileOutputStream(file);
bm.compress(CompressFormat.PNG, 100, ostream);
ostream.close(); 

Puoi usare Matrix per ridimensionare l'immagine della tua fotocamera ...

BitmapFactory.Options options=new BitmapFactory.Options();
InputStream is = getContentResolver().openInputStream(currImageURI);
bm = BitmapFactory.decodeStream(is,null,options);
int Height = bm.getHeight();
int Width = bm.getWidth();
int newHeight = 300;
int newWidth = 300;
float scaleWidth = ((float) newWidth) / Width;
float scaleHeight = ((float) newHeight) / Height;
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0,Width, Height, matrix, true);
BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);

bm = Bitmap.createScaledBitmap(bitmapSource, width, height, true);

:)

// la foto è un'immagine bitmap

Bitmap btm00 = Utils.getResizedBitmap(photo, 200, 200);

 setimage.setImageBitmap(btm00);

  And in Utils class :

public static Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    Matrix matrix = new Matrix();
    // RESIZE THE BIT MAP
    matrix.postScale(scaleWidth, scaleHeight);
    // RECREATE THE NEW BITMAP
    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height,
            matrix, false);
    return resizedBitmap;
}

BitmapFactory.Options options=new BitmapFactory.Options();
options.inSampleSize=2; //try to decrease decoded image 
Bitmap bitmap=BitmapFactory.decodeStream(is, null, options); 
bitmap.compress(Bitmap.CompressFormat.JPEG, 70, fos); //compressed bitmap to file 

resized = Bitmap.createScaledBitmap(yourImageBitmap,(int)(yourImageBitmap.getWidth()*0.9), (int)(yourBitmap.getHeight()*0.9), true);

Di seguito è riportata la funzione per ridimensionare la bitmap mantenendo le stesse proporzioni. Qui ho anche scritto un post sul blog dettagliato sull'argomento per spiegare questo metodo. Ridimensiona una bitmap mantenendo le stesse proporzioni .

   public static Bitmap resizeBitmap(Bitmap source, int maxLength) {
       try {
           if (source.getHeight() >= source.getWidth()) {
               int targetHeight = maxLength;
               if (source.getHeight() <= targetHeight) { // if image already smaller than the required height
                   return source;
               }

               double aspectRatio = (double) source.getWidth() / (double) source.getHeight();
               int targetWidth = (int) (targetHeight * aspectRatio);

               Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
               if (result != source) {
               }
               return result;
           } else {
               int targetWidth = maxLength;

               if (source.getWidth() <= targetWidth) { // if image already smaller than the required height
                   return source;
               }

               double aspectRatio = ((double) source.getHeight()) / ((double) source.getWidth());
               int targetHeight = (int) (targetWidth * aspectRatio);

               Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
               if (result != source) {
               }
               return result;

           }
       }
       catch (Exception e)
       {
           return source;
       }
   }

BitmapFactory.Options options=new BitmapFactory.Options();
            options.inSampleSize = 10;
            FixBitmap = BitmapFactory.decodeFile(ImagePath, options);
            //FixBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.gv);

           byteArrayOutputStream = new ByteArrayOutputStream();
           FixBitmap.compress(Bitmap.CompressFormat.JPEG, 80, byteArrayOutputStream); //compress to 50% of original image quality
           byteArray = byteArrayOutputStream.toByteArray();

           ConvertImage = Base64.encodeToString(byteArray, Base64.DEFAULT);