如何在android中调整2个图像的大小，因为一个保持不变的图像（可绘制文件夹中的.png图像）应该等于输入图像的大小（图像从用户从移动图库中输入）。我在opencv中使用resize(src, dst)函数来调整两个图像的大小，在java结束时我也不知道这种函数，因为我也检查this post但它看起来是某种额外加载的工作对我来说。
答案 0 :(得分：1)
我知道一些关于android中图像操作的方法。
将Drawable转换为位图：
public static Bitmap drawableToBitmap(Drawable drawable) {
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(width, height, drawable
.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
: Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, width, height);
drawable.draw(canvas);
return bitmap;
}
调整位图大小：
public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Matrix matrix = new Matrix();
float scaleWidht = ((float) w / width);
float scaleHeight = ((float) h / height);
matrix.postScale(scaleWidht, scaleHeight);
Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height,
matrix, true);
return newbmp;
}
您可以将第一个Drawable图像转换为Bitmap，然后使用第二种方法调整其大小。使用getWidth（）和getHeight（）来获取图像的参数。
我不知道这是否是最佳解决方案。如果我不太了解你的意图，请发表评论，我可以编辑我的答案。
修改
您可以获得Uri或图像的路径吗？
如果你得到Uri，请使用String path = uri.getPath();来获取路径。
然后
解码文件中的位图：
public static Bitmap getBitmap(String path) {
return BitmapFactory.decodeFile(String path);
}
如果图像的大小不是太大，直接加载它不会导致内存泄漏，一切正常。
但如果您不知道尺寸，我建议采用下一种方法。
从路径解码BitmapDrawable：
public static BitmapDrawable getScaledDrawable(Activity a, String path) {
Display display = a.getWindowManager().getDefaultDisplay();
float destWidth = display.getWidth();
float destHeight = display.getHeight();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
float srcWidth = options.outWidth;
float srcHeight = options.outHeight;
int inSampleSize = 1;
if (srcHeight > destHeight || srcWidth > destWidth) {
if (srcWidth > srcHeight) {
inSampleSize = Math.round(srcHeight / destHeight);
} else {
inSampleSize = Math.round(srcWidth / destWidth);
}
}
options = new BitmapFactory.Options();
options.inSampleSize = inSampleSize;
Bitmap bitmap = BitmapFactory.decodeFile(path, options);
return new BitmapDrawable(a.getResources(), bitmap);
}
此方法将返回一个缩放的BitmapDrawable对象，以防止内存泄漏。
如果您需要Bitmap而不是BitmapDrawable，请返回位图。
<强> EDIT2：
ThirdActivity.java：
public class ThirdActivity extends ActionBarActivity {
private static final int REQUEST_IMAGE = 0;
private Bitmap bitmapToResize;
private Button mGetImageButton;
private Button mResizeButton;
private ImageView mImageViewForGallery;
private ImageView mImageVIewForDrable;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_third);
mGetImageButton = (Button) findViewById(R.id.button_getImage);
mGetImageButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// SET action AND miniType
Intent intent = new Intent();
intent.setAction(Intent.ACTION_PICK);
intent.setType("image/*");
// REQUEST Uri of image
startActivityForResult(intent, REQUEST_IMAGE);
}
});
mResizeButton = (Button) findViewById(R.id.button_resize);
mResizeButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
resize();
}
});
mImageViewForGallery = (ImageView) findViewById(R.id.imageView);
mImageVIewForDrable = (ImageView) findViewById(R.id.imageViewFromDrable);
mImageVIewForDrable.setImageDrawable(getResources().getDrawable(R.drawable.ic_launcher));
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode != Activity.RESULT_OK) {return;}
if (requestCode == REQUEST_IMAGE) {
Uri uri = data.getData();
// SET image
mImageViewForGallery.setImageURI(uri);
Drawable drawable = mImageViewForGallery.getDrawable();
Log.e("asd", "Height:" + drawable.getIntrinsicHeight());
Log.e("asd", "Width:" + drawable.getIntrinsicWidth());
}
}
private void resize() {
if (mImageViewForGallery.getDrawable() != null) {
bitmapToResize = drawableToBitmap(mImageVIewForDrable.getDrawable());
int width = mImageViewForGallery.getDrawable().getIntrinsicWidth();
int height = mImageViewForGallery.getDrawable().getIntrinsicHeight();
bitmapToResize = zoomBitmap(bitmapToResize, width, height);
mImageVIewForDrable.setImageBitmap(bitmapToResize);
} else {
Log.e("asd", "setImageFirst");
}
}
public static Bitmap zoomBitmap(Bitmap bitmap, int w, int h) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Matrix matrix = new Matrix();
float scaleWidht = ((float) w / width);
float scaleHeight = ((float) h / height);
matrix.postScale(scaleWidht, scaleHeight);
Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, width, height,
matrix, true);
return newbmp;
}
public static Bitmap drawableToBitmap(Drawable drawable) {
int width = drawable.getIntrinsicWidth();
int height = drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(width, height, drawable
.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
: Bitmap.Config.RGB_565);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, width, height);
drawable.draw(canvas);
return bitmap;
}
}
activity_third.xml：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
android:background="@android:color/darker_gray"
tools:context="com.ch.summerrunner.ThirdActivity">
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/darker_gray">
<Button
android:id="@+id/button_getImage"
android:text="@string/gallery"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button
android:id="@+id/button_resize"
android:text="@string/resize"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="16dp"
android:layout_toRightOf="@id/button_getImage"/>
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:background="@android:color/white"
android:layout_below="@id/button_getImage"/>
<ImageView
android:id="@+id/imageViewFromDrable"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@android:color/white"
android:layout_below="@id/imageView"/>
</RelativeLayout>
</ScrollView>
</RelativeLayout>
答案 1 :(得分：0)
Bitmap bmpIn = BitmapFactory.decodeResource(view.getResources(), R.drawable.image);
BitMap bmpOut = Bitmap.createScaledBitmap(bmpIn, width, height, false);