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Verringern Sie die Bildgröße, ohne die Qualität in Android zu verlieren

So verringern Sie die Bildgröße, ohne die Qualität in Android zu verlieren.
Ich habe ein ImageView in meinem Projekt, ich muss ein größeres Bild darin einfügen.
Ich bin neu bei Android.
bitte helfen. 

36

Code unten für Skalierungsbild als Seitenverhältnis:

Bitmap bitmapImage = BitmapFactory.decodeFile("Your path");
int nh = (int) ( bitmapImage.getHeight() * (512.0 / bitmapImage.getWidth()) );
Bitmap scaled = Bitmap.createScaledBitmap(bitmapImage, 512, nh, true);
your_imageview.setImageBitmap(scaled);

Komprimieren Sie Ihr Image ohne Qualitätseinbußen wie WhatsApp

public String compressImage(String imageUri) {

        String filePath = getRealPathFromURI(imageUri);
        Bitmap scaledBitmap = null;

        BitmapFactory.Options options = new BitmapFactory.Options();

//      by setting this field as true, the actual bitmap pixels are not loaded in the memory. Just the bounds are loaded. If
//      you try the use the bitmap here, you will get null.
        options.inJustDecodeBounds = true;
        Bitmap bmp = BitmapFactory.decodeFile(filePath, options);

        int actualHeight = options.outHeight;
        int actualWidth = options.outWidth;

//      max Height and width values of the compressed image is taken as 816x612

        float maxHeight = 816.0f;
        float maxWidth = 612.0f;
        float imgRatio = actualWidth / actualHeight;
        float maxRatio = maxWidth / maxHeight;

//      width and height values are set maintaining the aspect ratio of the image

        if (actualHeight > maxHeight || actualWidth > maxWidth) {
            if (imgRatio < maxRatio) {
                imgRatio = maxHeight / actualHeight;
                actualWidth = (int) (imgRatio * actualWidth);
                actualHeight = (int) maxHeight;
            } else if (imgRatio > maxRatio) {
                imgRatio = maxWidth / actualWidth;
                actualHeight = (int) (imgRatio * actualHeight);
                actualWidth = (int) maxWidth;
            } else {
                actualHeight = (int) maxHeight;
                actualWidth = (int) maxWidth;

            }
        }

//      setting inSampleSize value allows to load a scaled down version of the original image

        options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight);

//      inJustDecodeBounds set to false to load the actual bitmap
        options.inJustDecodeBounds = false;

//      this options allow Android to claim the bitmap memory if it runs low on memory
        options.inPurgeable = true;
        options.inInputShareable = true;
        options.inTempStorage = new byte[16 * 1024];

        try {
//          load the bitmap from its path
            bmp = BitmapFactory.decodeFile(filePath, options);
        } catch (OutOfMemoryError exception) {
            exception.printStackTrace();

        }
        try {
            scaledBitmap = Bitmap.createBitmap(actualWidth, actualHeight, Bitmap.Config.ARGB_8888);
        } catch (OutOfMemoryError exception) {
            exception.printStackTrace();
        }

        float ratioX = actualWidth / (float) options.outWidth;
        float ratioY = actualHeight / (float) options.outHeight;
        float middleX = actualWidth / 2.0f;
        float middleY = actualHeight / 2.0f;

        Matrix scaleMatrix = new Matrix();
        scaleMatrix.setScale(ratioX, ratioY, middleX, middleY);

        Canvas canvas = new Canvas(scaledBitmap);
        canvas.setMatrix(scaleMatrix);
        canvas.drawBitmap(bmp, middleX - bmp.getWidth() / 2, middleY - bmp.getHeight() / 2, new Paint(Paint.FILTER_BITMAP_FLAG));

//      check the rotation of the image and display it properly
        ExifInterface exif;
        try {
            exif = new ExifInterface(filePath);

            int orientation = exif.getAttributeInt(
                    ExifInterface.TAG_ORIENTATION, 0);
            Log.d("EXIF", "Exif: " + orientation);
            Matrix matrix = new Matrix();
            if (orientation == 6) {
                matrix.postRotate(90);
                Log.d("EXIF", "Exif: " + orientation);
            } else if (orientation == 3) {
                matrix.postRotate(180);
                Log.d("EXIF", "Exif: " + orientation);
            } else if (orientation == 8) {
                matrix.postRotate(270);
                Log.d("EXIF", "Exif: " + orientation);
            }
            scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0,
                    scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix,
                    true);
        } catch (IOException e) {
            e.printStackTrace();
        }

        FileOutputStream out = null;
        String filename = getFilename();
        try {
            out = new FileOutputStream(filename);

//          write the compressed bitmap at the destination specified by filename.
            scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

        return filename;

    }

    public String getFilename() {
        File file = new File(Environment.getExternalStorageDirectory().getPath(), "MyFolder/Images");
        if (!file.exists()) {
            file.mkdirs();
        }
        String uriSting = (file.getAbsolutePath() + "/" + System.currentTimeMillis() + ".jpg");
        return uriSting;

    }

    private String getRealPathFromURI(String contentURI) {
        Uri contentUri = Uri.parse(contentURI);
        Cursor cursor = getContentResolver().query(contentUri, null, null, null, null);
        if (cursor == null) {
            return contentUri.getPath();
        } else {
            cursor.moveToFirst();
            int index = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
            return cursor.getString(index);
        }
    }

    public int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {
            final int heightRatio = Math.round((float) height / (float) reqHeight);
            final int widthRatio = Math.round((float) width / (float) reqWidth);
            inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
        }
        final float totalPixels = width * height;
        final float totalReqPixelsCap = reqWidth * reqHeight * 2;
        while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
            inSampleSize++;
        }

        return inSampleSize;
    }
70
Jitty Aandyan

Verwenden Sie diesen Code zum Komprimieren von Bitmaps in geringerer Größe.

BitmapFactory.Options Options = new BitmapFactory.Options();
Options.inSampleSize = 4;
Options.inJustDecodeBounds = false;
action_bitmap = BitmapFactory.decodeFile(Glob.savedImage, Options);

Glob.savedImage ist der String-Pfad des Bildes.

1

Klasse für CompressFile Image erstellen  

public class CompressFile {
    public static File getCompressedImageFile(File file, Context mContext) {
        try {
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;

            if (getFileExt(file.getName()).equals("png") || getFileExt(file.getName()).equals("PNG")) {
                o.inSampleSize = 6;
            } else {
                o.inSampleSize = 6;
            }

            FileInputStream inputStream = new FileInputStream(file);
            BitmapFactory.decodeStream(inputStream, null, o);
            inputStream.close();

            // The new size we want to scale to
            final int REQUIRED_SIZE = 100;

            // Find the correct scale value. It should be the power of 2.
            int scale = 1;
            while (o.outWidth / scale / 2 >= REQUIRED_SIZE &&
                    o.outHeight / scale / 2 >= REQUIRED_SIZE) {
                scale *= 2;
            }

            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            inputStream = new FileInputStream(file);

            Bitmap selectedBitmap = BitmapFactory.decodeStream(inputStream, null, o2);

            ExifInterface ei = new ExifInterface(file.getAbsolutePath());
            int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION,
                    ExifInterface.ORIENTATION_UNDEFINED);

            switch (orientation) {

                case ExifInterface.ORIENTATION_ROTATE_90:
                    rotateImage(selectedBitmap, 90);
                    break;

                case ExifInterface.ORIENTATION_ROTATE_180:
                    rotateImage(selectedBitmap, 180);
                    break;

                case ExifInterface.ORIENTATION_ROTATE_270:
                    rotateImage(selectedBitmap, 270);
                    break;

                case ExifInterface.ORIENTATION_NORMAL:

                default:
                    break;
            }
            inputStream.close();


            // here i override the original image file
            File folder = new File(Environment.getExternalStorageDirectory() + "/FolderName");
            boolean success = true;
            if (!folder.exists()) {
                success = folder.mkdir();
            }
            if (success) {
                File newFile = new File(new File(folder.getAbsolutePath()), file.getName());
                if (newFile.exists()) {
                    newFile.delete();
                }
                FileOutputStream outputStream = new FileOutputStream(newFile);

                if (getFileExt(file.getName()).equals("png") || getFileExt(file.getName()).equals("PNG")) {
                    selectedBitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream);
                } else {
                    selectedBitmap.compress(Bitmap.CompressFormat.JPEG, 100, outputStream);
                }

                return newFile;
            } else {
                return null;
            }
        } catch (Exception e) {
            return null;
        }
    }

    public static String getFileExt(String fileName) {
        return fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length());
    }

    public static Bitmap rotateImage(Bitmap source, float angle) {
        Matrix matrix = new Matrix();
        matrix.postRotate(angle);
        return Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(),
                matrix, true);
    }
}
0
Mohsinali

Die akzeptierte Antwort funktioniert einwandfrei, wenn ein Bild aus der Galerie abgerufen wird. Wenn Sie jedoch versuchen, ein Bild aus dem Dateimanager abzurufen, schlägt dies fehl. Der Grund dafür ist, dass der Uri ein anderes Format hat, das getRealPathFromURI(imageUri) nicht verwendet, um den tatsächlichen Pfad daraus zu ermitteln.

Um dieses Problem zu lösen, verwenden Sie die gleichen Methoden wie bei der akzeptierten Antwort, mit Ausnahme von copressImage() & getRealPathFromURI(), die optimiert wurden, um beide Bilder zu unterstützen, die aus File Manager & Gallery stammen:

public static String compressImage(Context context, Uri uri) {

    String filePath = getRealPathFromURI(context, uri);
    Bitmap scaledBitmap = null;

    BitmapFactory.Options options = new BitmapFactory.Options();

//      by setting this field as true, the actual bitmap pixels are not loaded in the memory. Just the bounds are loaded. If
//      you try the use the bitmap here, you will get null.
    options.inJustDecodeBounds = true;
    Bitmap bmp = BitmapFactory.decodeFile(filePath, options);

    int actualHeight = options.outHeight;
    int actualWidth = options.outWidth;

//      max Height and width values of the compressed image is taken as 816x612

    float maxHeight = 816.0f;
    float maxWidth = 612.0f;
    float imgRatio = actualWidth / actualHeight;
    float maxRatio = maxWidth / maxHeight;

//      width and height values are set maintaining the aspect ratio of the image

    if (actualHeight > maxHeight || actualWidth > maxWidth) {
        if (imgRatio < maxRatio) {
            imgRatio = maxHeight / actualHeight;
            actualWidth = (int) (imgRatio * actualWidth);
            actualHeight = (int) maxHeight;
        } else if (imgRatio > maxRatio) {
            imgRatio = maxWidth / actualWidth;
            actualHeight = (int) (imgRatio * actualHeight);
            actualWidth = (int) maxWidth;
        } else {
            actualHeight = (int) maxHeight;
            actualWidth = (int) maxWidth;

        }
    }

//      setting inSampleSize value allows to load a scaled down version of the original image

    options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight);

//      inJustDecodeBounds set to false to load the actual bitmap
    options.inJustDecodeBounds = false;

//      this options allow Android to claim the bitmap memory if it runs low on memory
    options.inPurgeable = true;
    options.inInputShareable = true;
    options.inTempStorage = new byte[16 * 1024];

    try {
//          load the bitmap from its path
        bmp = BitmapFactory.decodeFile(filePath, options);
    } catch (OutOfMemoryError exception) {
        exception.printStackTrace();

    }
    try {
        scaledBitmap = Bitmap.createBitmap(actualWidth, actualHeight, Bitmap.Config.ARGB_8888);
    } catch (OutOfMemoryError exception) {
        exception.printStackTrace();
    }

    float ratioX = actualWidth / (float) options.outWidth;
    float ratioY = actualHeight / (float) options.outHeight;
    float middleX = actualWidth / 2.0f;
    float middleY = actualHeight / 2.0f;

    Matrix scaleMatrix = new Matrix();
    scaleMatrix.setScale(ratioX, ratioY, middleX, middleY);

    Canvas canvas = new Canvas(scaledBitmap);
    canvas.setMatrix(scaleMatrix);
    canvas.drawBitmap(bmp, middleX - bmp.getWidth() / 2, middleY - bmp.getHeight() / 2, new Paint(Paint.FILTER_BITMAP_FLAG));

//      check the rotation of the image and display it properly
    ExifInterface exif;
    try {
        exif = new ExifInterface(filePath);

        int orientation = exif.getAttributeInt(
                ExifInterface.TAG_ORIENTATION, 0);
        Log.d("EXIF", "Exif: " + orientation);
        Matrix matrix = new Matrix();
        if (orientation == 6) {
            matrix.postRotate(90);
            Log.d("EXIF", "Exif: " + orientation);
        } else if (orientation == 3) {
            matrix.postRotate(180);
            Log.d("EXIF", "Exif: " + orientation);
        } else if (orientation == 8) {
            matrix.postRotate(270);
            Log.d("EXIF", "Exif: " + orientation);
        }
        scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0,
                scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix,
                true);
    } catch (IOException e) {
        e.printStackTrace();
    }

    FileOutputStream out = null;
    String filename = getFilename();
    try {
        out = new FileOutputStream(filename);

//          write the compressed bitmap at the destination specified by filename.
        scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }

    return filename;

}

 public static String getRealPathFromURI(Context context, Uri uri) {
    Uri queryUri = MediaStore.Files.getContentUri("external");
    String columnData = MediaStore.Files.FileColumns.DATA;
    String columnSize = MediaStore.Files.FileColumns.SIZE;

    String[] projectionData = {MediaStore.Files.FileColumns.DATA};


    String name = null;
    String size = null;

    Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
    if ((cursor != null) && (cursor.getCount() > 0)) {
        int nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
        int sizeIndex = cursor.getColumnIndex(OpenableColumns.SIZE);

        cursor.moveToFirst();

        name = cursor.getString(nameIndex);
        size = cursor.getString(sizeIndex);

        cursor.close();
    }

    String imagePath = "";
    if ((name != null) && (size != null)) {
        String selectionNS = columnData + " LIKE '%" + name + "' AND " + columnSize + "='" + size + "'";

        Cursor cursorLike = context.getContentResolver().query(queryUri, projectionData, selectionNS, null, null);

        if ((cursorLike != null) && (cursorLike.getCount() > 0)) {
            cursorLike.moveToFirst();
            int indexData = cursorLike.getColumnIndex(columnData);
            if (cursorLike.getString(indexData) != null) {
                imagePath = cursorLike.getString(indexData);
            }
            cursorLike.close();
        }
    }

    return imagePath;
}
0
Zain