How to limit the height and width of the image when taking it from the File Picker in android java-CodePudding

//How to limit the height and width of the image when taking it from the File Picker

CodePudding user response：

You can use the BitmapFactory class to decode the image and specify the maximum height and width you want for the image. Like this:

// set desired dimensions for the image
int targetWidth = 200;
int targetHeight = 200;

// get dimensions of original image
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
BitmapFactory.decodeFile(imagePath, bmOptions);
int photoWidth = bmOptions.outWidth;
int photoHeight = bmOptions.outHeight;

// determine how much to scale down image
int scaleFactor = Math.min(photoWidth / targetWidth, photoHeight / targetHeight);

// decode image file into a Bitmap sized to fill the View
bmOptions.inJustDecodeBounds = false;
bmOptions.inSampleSize = scaleFactor;
bmOptions.inPurgeable = true;

Bitmap bitmap = BitmapFactory.decodeFile(imagePath, bmOptions);

CodePudding user response：

You can use the BitmapFactory class to decode the image file and specify the desired width and height in the BitmapFactory.Options object. Example:

// Get the file path from the File Picker
String filePath = // ...

// Decode the image file into a Bitmap
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath, options);

// Calculate the desired size
int desiredWidth = 200;
int desiredHeight = 200;
int width = options.outWidth;
int height = options.outHeight;
int inSampleSize = 1;

if (height > desiredHeight || width > desiredWidth) {
    final int halfHeight = height / 2;
    final int halfWidth = width / 2;

    // Calculate the largest inSampleSize value that is a power of 2 and keeps both
    // height and width larger than the requested height and width.
    while ((halfHeight / inSampleSize) >= desiredHeight
            && (halfWidth / inSampleSize) >= desiredWidth) {
        inSampleSize *= 2;
    }
}

// Decode the image file into a Bitmap with the desired size
options.inSampleSize = inSampleSize;
options.inJustDecodeBounds = false;
Bitmap bitmap = BitmapFactory.decodeFile(filePath, options);

This will decode the image file into a Bitmap object with a width and height that is at most desiredWidth and desiredHeight, respectively.