android - studio - programa para reducir tamaño de fotos gratis

¿Cómo comprimir el tamaño de la imagen?

Question

Quiero capturar la imagen en baja resolución utilizando la api de la cámara android, pero cuando capturé la imagen tomará la resolución predeterminada de la cámara del dispositivo. Así que quiero capturar la imagen en baja resolución o tamaño pequeño en el momento de la captura o cómo puedo comprimir la imagen grande en pequeño tamaño en android?

Answer 1

Solo prueba este

byte[] data = null;
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    bi.compress(Bitmap.CompressFormat.JPEG, 100, baos);
    data = baos.toByteArray();

Answer 2

Creo que estás preguntando sobre el tamaño de la imagen Reduciendo:

    public Bitmap ShrinkBitmap(String file, int width, int height)
{
    BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
    bmpFactoryOptions.inJustDecodeBounds = true;
    Bitmap bitmap = BitmapFactory.decodeFile(file, bmpFactoryOptions);

    int heightRatio = (int) Math.ceil(bmpFactoryOptions.outHeight / (float) height);
    int widthRatio = (int) Math.ceil(bmpFactoryOptions.outWidth / (float) width);

    if(heightRatio > 1 || widthRatio > 1)
    {
        if(heightRatio > widthRatio)
        {
            bmpFactoryOptions.inSampleSize = heightRatio;
        }
        else
        {
            bmpFactoryOptions.inSampleSize = widthRatio;
        }
    }

    bmpFactoryOptions.inJustDecodeBounds = false;
    bitmap = BitmapFactory.decodeFile(file, bmpFactoryOptions);
    return bitmap;
}

Answer 3

Por favor, revise el método compressImage que he usado para comprimir la imagen.

public static String compressImage(String imageUri, Activity activity) {
    String filename = "";
    try {
        String filePath = getRealPathFromURI(imageUri, activity);
        Bitmap scaledBitmap = null;

        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        Bitmap bmp = BitmapFactory.decodeFile(filePath, options);

        int actualHeight = options.outHeight;
        int actualWidth = options.outWidth;
        float maxHeight = 816.0f;
        float maxWidth = 612.0f;
        float imgRatio = actualWidth / actualHeight;
        float maxRatio = maxWidth / maxHeight;

        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;

            }
        }

        options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight);
        options.inJustDecodeBounds = false;
        options.inDither = false;
        options.inPurgeable = true;
        options.inInputShareable = true;
        options.inTempStorage = new byte[16 * 1024];

        try {
            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;
        if (scaledBitmap != null) {
            canvas = new Canvas(scaledBitmap);
            canvas.setMatrix(scaleMatrix);
            canvas.drawBitmap(bmp, middleX - bmp.getWidth() / 2, middleY - bmp.getHeight() / 2, new Paint(Paint.FILTER_BITMAP_FLAG));
        }


        ExifInterface exif;
        try {
            exif = new ExifInterface(filePath);

            int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 0);

            Matrix matrix = new Matrix();
            if (orientation == 6) {
                matrix.postRotate(90);

            } else if (orientation == 3) {
                matrix.postRotate(180);

            } else if (orientation == 8) {
                matrix.postRotate(270);

            }
            if (scaledBitmap != null) {
                scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0, scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix, true);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        FileOutputStream out;
        filename = getFilename(activity);
        try {
            out = new FileOutputStream(filename);
            if (scaledBitmap != null) {
                scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);
            }

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

    return filename;
}

private static 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;
}

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

Answer 4

Pruebe este método, esto convertirá su archivo de imagen a un formato comprimido, y puede personalizar el nivel de compresión al comparar el valor de x & y en el código (indicado en la línea de comentarios)

      File mImageFile = saveBitmapToFile(ImageFile);

      public File saveBitmapToFile(File file){

      try {

        // BitmapFactory options to downsize the image
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        o.inSampleSize = 6;
        // factor of downsizing the image

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

        // The new size we want to scale to
        final int REQUIRED_SIZE=200;        // x............

        // 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);
        inputStream.close();

        // here i override the original image file
        File outPutFile = File.createTempFile("abc","image");
        FileOutputStream outputStream = new FileOutputStream(outPutFile);
                                                  // y.......
        selectedBitmap.compress(Bitmap.CompressFormat.JPEG, 95 , outputStream);

        return outPutFile;
    } catch (Exception e) {
        return null;
    }
}

Gracias

Answer 5

Puede comprimir la imagen de mapa de bits de esta manera.

ByteArrayOutputStream out = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, out);

Aquí 100 es la calidad de la imagen y puede cambiar el formato de la imagen para obtener una imagen de baja resolución.

Answer 6

Puede crear un mapa de bits con la imagen capturada de la siguiente manera:

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

Aquí puede especificar el ancho y el alto del mapa de bits que desea establecer en su ImageView. La altura y el ancho que puede establecer según la ppp de la pantalla del dispositivo también, mediante la lectura de ppp de la pantalla de diferentes dispositivos mediante programación.

Answer 7

Puedes probar este código

    public class ScalingUtilities {

    /**
     * Utility function for decoding an image resource. The decoded bitmap will
     * be optimized for further scaling to the requested destination dimensions
     * and scaling logic.
     *
     * @param res The resources object containing the image data
     * @param resId The resource id of the image data
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Decoded bitmap
     */
    public static Bitmap decodeResource(Resources res, int resId, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(res, resId, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeResource(res, resId, options);

        return unscaledBitmap;
    }
    public static Bitmap decodeFile(String path, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeFile(path, options);

        return unscaledBitmap;
    }

    /**
     * Utility function for creating a scaled version of an existing bitmap
     *
     * @param unscaledBitmap Bitmap to scale
     * @param dstWidth Wanted width of destination bitmap
     * @param dstHeight Wanted height of destination bitmap
     * @param scalingLogic Logic to use to avoid image stretching
     * @return New scaled bitmap object
     */
    public static Bitmap createScaledBitmap(Bitmap unscaledBitmap, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Rect srcRect = calculateSrcRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Rect dstRect = calculateDstRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Bitmap scaledBitmap = Bitmap.createBitmap(dstRect.width(), dstRect.height(),
                Config.ARGB_8888);
        Canvas canvas = new Canvas(scaledBitmap);
        canvas.drawBitmap(unscaledBitmap, srcRect, dstRect, new Paint(Paint.FILTER_BITMAP_FLAG));

        return scaledBitmap;
    }

    /**
     * ScalingLogic defines how scaling should be carried out if source and
     * destination image has different aspect ratio.
     *
     * CROP: Scales the image the minimum amount while making sure that at least
     * one of the two dimensions fit inside the requested destination area.
     * Parts of the source image will be cropped to realize this.
     *
     * FIT: Scales the image the minimum amount while making sure both
     * dimensions fit inside the requested destination area. The resulting
     * destination dimensions might be adjusted to a smaller size than
     * requested.
     */
    public static enum ScalingLogic {
        CROP, FIT
    }

    /**
     * Calculate optimal down-sampling factor given the dimensions of a source
     * image, the dimensions of a destination area and a scaling logic.
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal down scaling sample size for decoding
     */
    public static int calculateSampleSize(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcWidth / dstWidth;
            } else {
                return srcHeight / dstHeight;
            }
        } else {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcHeight / dstHeight;
            } else {
                return srcWidth / dstWidth;
            }
        }
    }

    /**
     * Calculates source rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal source rectangle
     */
    public static Rect calculateSrcRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.CROP) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                final int srcRectWidth = (int)(srcHeight * dstAspect);
                final int srcRectLeft = (srcWidth - srcRectWidth) / 2;
                return new Rect(srcRectLeft, 0, srcRectLeft + srcRectWidth, srcHeight);
            } else {
                final int srcRectHeight = (int)(srcWidth / dstAspect);
                final int scrRectTop = (int)(srcHeight - srcRectHeight) / 2;
                return new Rect(0, scrRectTop, srcWidth, scrRectTop + srcRectHeight);
            }
        } else {
            return new Rect(0, 0, srcWidth, srcHeight);
        }
    }

    /**
     * Calculates destination rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal destination rectangle
     */
    public static Rect calculateDstRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return new Rect(0, 0, dstWidth, (int)(dstWidth / srcAspect));
            } else {
                return new Rect(0, 0, (int)(dstHeight * srcAspect), dstHeight);
            }
        } else {
            return new Rect(0, 0, dstWidth, dstHeight);
        }
    }


    public static String decodeFile(String path,int DESIREDWIDTH, int DESIREDHEIGHT, int type) {
        String strMyImagePath = null;
        Bitmap scaledBitmap = null;
        Bitmap rotated = null;

        try {
            // Part 1: Decode image
            Bitmap unscaledBitmap = ScalingUtilities.decodeFile(path, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);

//            if (!(unscaledBitmap.getWidth() <= DESIREDWIDTH && unscaledBitmap.getHeight() <= DESIREDHEIGHT)) {
//                // Part 2: Scale image
//                scaledBitmap = ScalingUtilities.createScaledBitmap(unscaledBitmap, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);
//            } else {
//                unscaledBitmap.recycle();
//                return path;
//            }

            // Store to tmp file
            scaledBitmap = ScalingUtilities.createScaledBitmap(unscaledBitmap, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);

            String extr = Environment.getExternalStorageDirectory().toString();
            File mFolder = new File(extr + com.vt.vsmart.utils.Config.SD_PATH+"/image");
            if (!mFolder.exists()) {
                mFolder.mkdir();
            }

            String s = type+"temp.jpg";

            File f = new File(mFolder.getAbsolutePath(), s);

            strMyImagePath = f.getAbsolutePath();
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(f);
//                scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 95, fos);

                // quay anh 90 do
                Matrix matrix = new Matrix();

                matrix.postRotate(90);

                rotated = Bitmap.createBitmap(scaledBitmap, 0, 0, scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix, true);

                rotated.compress(Bitmap.CompressFormat.JPEG, 95, fos);

                fos.flush();
                fos.close();
            } catch (FileNotFoundException e) {

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

                e.printStackTrace();
            }

//            scaledBitmap.recycle();
            rotated.recycle();
        } catch (Throwable e) {
        }

        if (strMyImagePath == null) {
            return path;
        }
        return strMyImagePath;

    }

    // check anh bi quay
    public int getCameraPhotoOrientation(Context context, Uri imageUri, String imagePath){
        int rotate = 0;
        try {
            context.getContentResolver().notifyChange(imageUri, null);
            File imageFile = new File(imagePath);

            ExifInterface exif = new ExifInterface(imageFile.getAbsolutePath());
            int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);

            switch (orientation) {
            case ExifInterface.ORIENTATION_ROTATE_270:
                rotate = 270;
                break;
            case ExifInterface.ORIENTATION_ROTATE_180:
                rotate = 180;
                break;
            case ExifInterface.ORIENTATION_ROTATE_90:
                rotate = 90;
                break;
            }

//            Log.i("RotateImage", "Exif orientation: " + orientation);
//            Log.i("RotateImage", "Rotate value: " + rotate);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return rotate;
    }

}

Funciona para mi. Espero que te pueda ayudar!

Answer 8

Resuelvo este problema de esta manera, luego mejoraré el código.

protected Void doInBackground(byte[]... data) {
        FileOutputStream outStream = null;

        // Write to Internal Storage
        try {
            File dir = new File (context.getFilesDir());
            dir.mkdirs();

            String fileName ="image.jpg";
            File outFile = new File(dir, fileName);
            outFile.setExecutable(true, false);
            outFile.setWritable(true, false);
            outStream = new FileOutputStream(outFile);
            outStream.write(data[0]);
            outStream.flush();
            outStream.close();
            InputStream in = new FileInputStream(context.getFilesDir()+"image.jpg");
            Bitmap bm2 = BitmapFactory.decodeStream(in);
            OutputStream stream = new FileOutputStream(String.valueOf(context.getFilesDir()+pathImage+"/"+idPicture+".jpg"));
            bm2.compress(Bitmap.CompressFormat.JPEG, 50, stream);
            stream.close();
            in.close();

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
        }
        return null;
    }

Answer 9

Utilice Compressor (biblioteca de compresión de imágenes). Visite este github.com/zetbaitsu/Compressor para la documentación del código.

1. añadir dependencia en gradle (nivel de aplicación)

   dependencias {compile ''id.zelory: compressor: 2.1.0''}

2. Para comprimir la imagen utiliza uno de estos métodos:

(i) Comprimir archivo de imagen:

File compressedImageFile = new Compressor(this).compressToFile(actualImageFile);

(ii) Comprimir archivo de imagen a mapa de bits:

Bitmap compressedImageBitmap = new Compressor(this).compressToBitmap(actualImageFile);

Answer 10

usa esta clase para comprimir la imagen

import android.content.Context
import android.graphics.Bitmap
import android.graphics.BitmapFactory
import android.graphics.Canvas
import android.graphics.Matrix
import android.graphics.Paint
import android.net.Uri
import android.os.Environment
import java.io.*


class ImageFile(val uri: Uri, name: String) {

    val filename: String

    init {
        val file = File(Environment.getExternalStorageDirectory().toString() + "/Documents")
        if (!file.exists()) {
            file.mkdirs()
        }
        val fileNoMedia = File(file.absolutePath + "/.nomedia")
        if (!fileNoMedia.exists())
            fileNoMedia.createNewFile()
        if (name.toLowerCase().endsWith(".pdf")) {
            filename = file.absolutePath + "/" + System.currentTimeMillis() + ".pdf"
        } else {
            filename = file.absolutePath + "/" + System.currentTimeMillis() + ".jpg"
        }
    }

    @Throws(IOException::class)
    fun copyFileStream(context: Context, uri: Uri): String {
        if (filename.endsWith(".pdf") || filename.endsWith(".PDF")) {
            var ins: InputStream? = null
            var os: OutputStream? = null
            try {
                ins = context.getContentResolver().openInputStream(uri)
                os = FileOutputStream(filename)
                val buffer = ByteArray(1024)
                var length: Int = ins.read(buffer)
                while (length > 0) {
                    os.write(buffer, 0, length);
                    length = ins.read(buffer)
                }
            } catch (e: Exception) {
                e.printStackTrace();
            } finally {
                ins?.close()
                os?.close()
            }
        } else {
            var ins: InputStream? = null
            var os: OutputStream? = null
            try {
                ins = context.getContentResolver().openInputStream(uri)
                var scaledBitmap: Bitmap? = null
                val options = BitmapFactory.Options()
                options.inJustDecodeBounds = true
                var bmp = BitmapFactory.decodeStream(ins, null, options)
                var actualHeight = options.outHeight
                var actualWidth = options.outWidth

                //      max Height and width values of the compressed image is taken as 816x612
                val maxHeight = 816.0f
                val maxWidth = 612.0f
                var imgRatio = (actualWidth / actualHeight).toFloat()
                val 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 = (imgRatio * actualWidth).toInt()
                        actualHeight = maxHeight.toInt()
                    } else if (imgRatio > maxRatio) {
                        imgRatio = maxWidth / actualWidth
                        actualHeight = (imgRatio * actualHeight).toInt()
                        actualWidth = maxWidth.toInt()
                    } else {
                        actualHeight = maxHeight.toInt()
                        actualWidth = maxWidth.toInt()

                    }
                }

                //      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 = ByteArray(16 * 1024)


                try {
                    //          load the bitmap from its path
                    ins.close()
                    ins = context.getContentResolver().openInputStream(uri)
                    bmp = BitmapFactory.decodeStream(ins, null, options)
                } catch (exception: OutOfMemoryError) {
                    exception.printStackTrace()

                }

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

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

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

                val canvas = Canvas(scaledBitmap!!)
                canvas.matrix = scaleMatrix
                canvas.drawBitmap(bmp, middleX - bmp.width / 2, middleY - bmp.height / 2, Paint(Paint.FILTER_BITMAP_FLAG))

                os = FileOutputStream(filename)
                scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 80, os)
                val buffer = ByteArray(1024)
                var length: Int = ins.read(buffer)
                while (length > 0) {
                    os.write(buffer, 0, length);
                    length = ins.read(buffer)
                }
            } catch (e: Exception) {
                e.printStackTrace();
            } finally {
                ins?.close()
                os?.close()
            }
        }
        return filename
    }

    fun calculateInSampleSize(options: BitmapFactory.Options, reqWidth: Int, reqHeight: Int): Int {
        val height = options.outHeight
        val width = options.outWidth
        var inSampleSize = 1
        if (height > reqHeight || width > reqWidth) {
            val heightRatio = Math.round(height.toFloat() / reqHeight.toFloat())
            val widthRatio = Math.round(width.toFloat() / reqWidth.toFloat())
            inSampleSize = if (heightRatio < widthRatio) heightRatio else widthRatio
        }
        val totalPixels = (width * height).toFloat()
        val totalReqPixelsCap = (reqWidth * reqHeight * 2).toFloat()
        while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
            inSampleSize++
        }

        return inSampleSize
    }
}

https://lalitjadav007.blogspot.in/2017/08/compress-image-in-android.html

Answer 11

Intenta esto está funcionando muy bien conmigo.

private String decodeFile(String path) {
        String strMyImagePath = null;
        Bitmap scaledBitmap = null;

        try {
            // Part 1: Decode image
            Bitmap unscaledBitmap = ScalingUtilities.decodeFile(path, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);

            if (!(unscaledBitmap.getWidth() <= 800 && unscaledBitmap.getHeight() <= 800)) {
                // Part 2: Scale image
                scaledBitmap = ScalingUtilities.createScaledBitmap(unscaledBitmap, DESIREDWIDTH, DESIREDHEIGHT, ScalingLogic.FIT);
            } else {
                unscaledBitmap.recycle();
                return path;
            }

            // Store to tmp file

            String extr = Environment.getExternalStorageDirectory().toString();
            File mFolder = new File(extr + "/myTmpDir");
            if (!mFolder.exists()) {
                mFolder.mkdir();
            }

            String s = "tmp.png";

            File f = new File(mFolder.getAbsolutePath(), s);

            strMyImagePath = f.getAbsolutePath();
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(f);
                scaledBitmap.compress(Bitmap.CompressFormat.PNG, 70, fos);
                fos.flush();
                fos.close();
            } catch (FileNotFoundException e) {

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

                e.printStackTrace();
            }

            scaledBitmap.recycle();
        } catch (Throwable e) {
        }

        if (strMyImagePath == null) {
            return path;
        }
        return strMyImagePath;

    }

Clase de utilidad

public class ScalingUtilities {

    /**
     * Utility function for decoding an image resource. The decoded bitmap will
     * be optimized for further scaling to the requested destination dimensions
     * and scaling logic.
     *
     * @param res The resources object containing the image data
     * @param resId The resource id of the image data
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Decoded bitmap
     */
    public static Bitmap decodeResource(Resources res, int resId, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(res, resId, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeResource(res, resId, options);

        return unscaledBitmap;
    }
    public static Bitmap decodeFile(String path, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Options options = new Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(path, options);
        options.inJustDecodeBounds = false;
        options.inSampleSize = calculateSampleSize(options.outWidth, options.outHeight, dstWidth,
                dstHeight, scalingLogic);
        Bitmap unscaledBitmap = BitmapFactory.decodeFile(path, options);

        return unscaledBitmap;
    }

    /**
     * Utility function for creating a scaled version of an existing bitmap
     *
     * @param unscaledBitmap Bitmap to scale
     * @param dstWidth Wanted width of destination bitmap
     * @param dstHeight Wanted height of destination bitmap
     * @param scalingLogic Logic to use to avoid image stretching
     * @return New scaled bitmap object
     */
    public static Bitmap createScaledBitmap(Bitmap unscaledBitmap, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        Rect srcRect = calculateSrcRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Rect dstRect = calculateDstRect(unscaledBitmap.getWidth(), unscaledBitmap.getHeight(),
                dstWidth, dstHeight, scalingLogic);
        Bitmap scaledBitmap = Bitmap.createBitmap(dstRect.width(), dstRect.height(),
                Config.ARGB_8888);
        Canvas canvas = new Canvas(scaledBitmap);
        canvas.drawBitmap(unscaledBitmap, srcRect, dstRect, new Paint(Paint.FILTER_BITMAP_FLAG));

        return scaledBitmap;
    }

    /**
     * ScalingLogic defines how scaling should be carried out if source and
     * destination image has different aspect ratio.
     *
     * CROP: Scales the image the minimum amount while making sure that at least
     * one of the two dimensions fit inside the requested destination area.
     * Parts of the source image will be cropped to realize this.
     *
     * FIT: Scales the image the minimum amount while making sure both
     * dimensions fit inside the requested destination area. The resulting
     * destination dimensions might be adjusted to a smaller size than
     * requested.
     */
    public static enum ScalingLogic {
        CROP, FIT
    }

    /**
     * Calculate optimal down-sampling factor given the dimensions of a source
     * image, the dimensions of a destination area and a scaling logic.
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal down scaling sample size for decoding
     */
    public static int calculateSampleSize(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcWidth / dstWidth;
            } else {
                return srcHeight / dstHeight;
            }
        } else {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return srcHeight / dstHeight;
            } else {
                return srcWidth / dstWidth;
            }
        }
    }

    /**
     * Calculates source rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal source rectangle
     */
    public static Rect calculateSrcRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.CROP) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                final int srcRectWidth = (int)(srcHeight * dstAspect);
                final int srcRectLeft = (srcWidth - srcRectWidth) / 2;
                return new Rect(srcRectLeft, 0, srcRectLeft + srcRectWidth, srcHeight);
            } else {
                final int srcRectHeight = (int)(srcWidth / dstAspect);
                final int scrRectTop = (int)(srcHeight - srcRectHeight) / 2;
                return new Rect(0, scrRectTop, srcWidth, scrRectTop + srcRectHeight);
            }
        } else {
            return new Rect(0, 0, srcWidth, srcHeight);
        }
    }

    /**
     * Calculates destination rectangle for scaling bitmap
     *
     * @param srcWidth Width of source image
     * @param srcHeight Height of source image
     * @param dstWidth Width of destination area
     * @param dstHeight Height of destination area
     * @param scalingLogic Logic to use to avoid image stretching
     * @return Optimal destination rectangle
     */
    public static Rect calculateDstRect(int srcWidth, int srcHeight, int dstWidth, int dstHeight,
            ScalingLogic scalingLogic) {
        if (scalingLogic == ScalingLogic.FIT) {
            final float srcAspect = (float)srcWidth / (float)srcHeight;
            final float dstAspect = (float)dstWidth / (float)dstHeight;

            if (srcAspect > dstAspect) {
                return new Rect(0, 0, dstWidth, (int)(dstWidth / srcAspect));
            } else {
                return new Rect(0, 0, (int)(dstHeight * srcAspect), dstHeight);
            }
        } else {
            return new Rect(0, 0, dstWidth, dstHeight);
        }
    }

}