我想从照片中拍摄并将其保存到SD卡，然后当涉及到图库中的图像时，应压缩其大小，以便图像应适合图像视图，并且没有错误 内存错误 错误，轻松转到其他活动
谢谢
试试这个;它可能会帮助你。
public class bitmaptest extends Activity {
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
LinearLayout linLayout = new LinearLayout(this);
// load the origial BitMap (500 x 500 px)
Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
R.drawable.android);
int width = bitmapOrg.width();
int height = bitmapOrg.height();
int newWidth = 200;
int newHeight = 200;
// calculate the scale - in this case = 0.4f
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// createa matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);
// rotate the Bitmap
matrix.postRotate(45);
// recreate the new Bitmap
Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
width, height, matrix, true);
// make a Drawable from Bitmap to allow to set the BitMap
// to the ImageView, ImageButton or what ever
BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);
ImageView imageView = new ImageView(this);
// set the Drawable on the ImageView
imageView.setImageDrawable(bmd);
// center the Image
imageView.setScaleType(ScaleType.CENTER);
// add ImageView to the Layout
linLayout.addView(imageView,
new LinearLayout.LayoutParams(
LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT
)
);
// set LinearLayout as ContentView
setContentView(linLayout);
}
}
您也可以与Bitmap.createScaledBitmap(yourimage, 160, 160, true);核实
您可以在项目中添加以下代码以从路径压缩图像
您只需要传递从图库中选择的图像路径
public static String compressImage(Context context,String imageUri) {
String filePath = getRealPathFromURI(imageUri,context);
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 maxWidth,maxHeight;
//if the image has width>height, we'll want the final image to be somewhere in the dimension of 720x1280
//if the image has width>height, we'll want the final image to be of 1280x720
//if the image has width=height(square), we'll want the final image to be of 1280x1280
if(actualHeight>actualWidth){
maxHeight = Constants.maxHeightFloat;
maxWidth = Constants.maxWidthFloat;
}else if(actualWidth>actualHeight){
maxHeight = Constants.maxWidthFloat;
maxWidth = Constants.maxHeightFloat;
}else {
maxHeight = Constants.maxHeightFloat;
maxWidth = Constants.maxHeightFloat;
}
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.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();
}
if(filename!=null)
addImageToGallery(filename,context);
return filename;
}