使用 Android 像 Whatsapp 和 Facebook 一样压缩图像

Question

我已经尝试使用此代码进行转换 image 它适用于标题位大小，但我想调整动态图像的大小，例如 Whatsapp 和 Facebook。在 Whatsapp 4 到 5 MB 图像被压缩成 KB 那么我该怎么做呢？

 public String compressImage(String imageUri) {

    String filePath = getRealPathFromURI(imageUri);
    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.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 = 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);
        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);

       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;
}

此代码转换图像但在我的项目要求中是这样的。

Answer 1

对于裁剪图像你可以使用这个lib

您也可以使用此代码压缩图像。

public Bitmap decodeFile(String filePath) {

BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, o);

// The new size we want to scale to
final int REQUIRED_SIZE = 1024;

// Find the correct scale value. It should be the power of 2.
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
    if (width_tmp < REQUIRED_SIZE && height_tmp < REQUIRED_SIZE)
        break;
    width_tmp /= 2;
    height_tmp /= 2;
    scale *= 2;
}

// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
Bitmap image = BitmapFactory.decodeFile(filePath, o2);

 ExifInterface exif;
    try 
    {               
        exif = new ExifInterface(filePath);
        int exifOrientation = exif.getAttributeInt(
                ExifInterface.TAG_ORIENTATION,
                ExifInterface.ORIENTATION_NORMAL);

        int rotate = 0;
        switch (exifOrientation) {
        case ExifInterface.ORIENTATION_ROTATE_90:
            rotate = 90;
            break;

        case ExifInterface.ORIENTATION_ROTATE_180:
            rotate = 180;
            break;

        case ExifInterface.ORIENTATION_ROTATE_270:
            rotate = 270;
            break;
        }

        if (rotate != 0) {
            int w = image.getWidth();
            int h = image.getHeight();

            // Setting pre rotate
            Matrix mtx = new Matrix();
            mtx.preRotate(rotate);

            // Rotating Bitmap & convert to ARGB_8888, required by tess
            image = Bitmap.createBitmap(image, 0, 0, w, h, mtx, false);

        }
    } catch (IOException e) {
             return null;
    }
    return image.copy(Bitmap.Config.ARGB_8888, true);
}

使用 Android 像 Whatsapp 和 Facebook 一样压缩图像

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