Android 实现压缩图片到任意尺寸

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我是靠谱客的博主开放大船，最近开发中收集的这篇文章主要介绍Android 实现压缩图片到任意尺寸，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

之前写过一篇博客，讲的是如何利用Picasso 来实现压缩图片到任意尺寸：

https://blog.csdn.net/wei1583812/article/details/55271209

后来我用安卓的原生方法实现了压缩图片到任意尺寸，比picasso 要快很多，且不用导入picasso 。不过picasso 也是用的我说的这种方法，只不过是因为它在处理中中转了几层，导致慢了一些。话不多说，贴代码，可以直接拿去用：

public class BitmapUtils {
/**
* 返回图片宽高数组，第0个是宽，第1个是高
*/
public static int[] getBitmapWidthHeight(final String path) {
BitmapFactory.Options options = new BitmapFactory.Options();
/**
* 最关键在此，把options.inJustDecodeBounds = true;
* 这里再decodeFile()，返回的bitmap为空，但此时调用options.outHeight时，已经包含了图片的高了
*/
options.inJustDecodeBounds = true;
Bitmap bitmap = BitmapFactory.decodeFile(path, options); // 此时返回的bitmap为null
int[] size = new int[2];
size[0] = options.outWidth;
size[1] = options.outHeight;
return size;
}
public static String getPathByUri(Context context, Uri uri) {
Activity activity = null;
if (context instanceof Activity) {
activity = (Activity) context;
}
if (activity == null) {
return null;
}
String path = null;
if (uri == null) {
return path;
}
if ("content".equals(uri.getScheme())) {
String[] projection = {MediaStore.Images.Media.DATA};
Cursor cursor = activity.managedQuery(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
path = cursor.getString(column_index);
} else if ("file".equals(uri.getScheme())) {
path = uri.getPath();
}
return path;
}
/**
* 此方法仅仅用于计算createScaledBitmap() 方法获取Bitmap 时的缩放比例。
* 目的是为了防止OOM
*/
private static int getOptionSize(final float size) {
int optionSize = 1;
if (size >= 2f && size < 4f) {
optionSize = 2;
} else if (size >= 4f && size < 8f) {
optionSize = 4;
} else if (size >= 8f && size < 16) {
optionSize = 8;
} else if (size >= 16f) {
optionSize = 16;
}
return optionSize;
}
/**
* 保存图片到sdcard
*/
public static void saveBitmap(final Bitmap bmp, final MyCallback callback) {
if (callback != null) {
callback.onPrepare();
}
new Thread(new Runnable() {
@Override
public void run() {
String fileName = System.currentTimeMillis() + ".jpg";
File file = new File(BaseSDCardUtils.SDCARD_PATH, fileName);
try {
FileOutputStream fos = new FileOutputStream(file);
bmp.compress(Bitmap.CompressFormat.JPEG, 100, fos);
fos.flush();
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
if (callback != null) {
callback.onError();
}
} catch (IOException e) {
e.printStackTrace();
if (callback != null) {
callback.onError();
}
}
String path = file.getAbsolutePath();
if (callback != null) {
callback.onSucceed(path);
}
}
}).start();
}
/**
* 按原图比例缩放裁剪图片
*
* @param activity
BaseLibActivity
* @param imagePath
图片的路径
* @param imageWidth 想要被缩放到的target图片宽度，我会根据此宽度和原图的比例，去计算target图片高度
* @param callback
回调监听
*/
public static void createScaledBitmap(final BaseLibActivity activity, final String imagePath, final int imageWidth, final MyCallback callback) {
if (callback == null) {
throw new NullPointerException("MyCallback must not null");
}
callback.onPrepare();
if (TextUtils.isEmpty(imagePath) || !(new File(imagePath).exists())) {
callback.onError();
return;
}
//原图宽度大于传入的宽度才压缩，否则不压缩，直接返回原图路径
final int[] size = getBitmapWidthHeight(imagePath);
if (size[0] <= imageWidth) {
callback.onSucceed(imagePath);
return;
}
new Thread() {
@Override
public void run() {
super.run();
int imageHeight = (int) (size[1] * 1f * imageWidth * 1f / size[0] * 1f);
float scale = size[0] * 1f / imageWidth * 1f;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = getOptionSize(scale);
Bitmap targetBitmap = Bitmap.createScaledBitmap(BitmapFactory.decodeFile(imagePath, options), imageWidth, imageHeight, true);
saveBitmap(targetBitmap, new MyCallback() {
@Override
public void onPrepare() {
}
@Override
public void onSucceed(final Object path) {
if (activity != null && !activity.isFinishing()) {
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
callback.onSucceed(path);
}
});
}
}
@Override
public void onError() {
if (activity != null && !activity.isFinishing()) {
activity.runOnUiThread(new Runnable() {
@Override
public void run() {
callback.onError();
}
});
}
}
});
}
}.start();
}
/**
* 按原图比例缩放裁剪图片
*
* @param activity
BaseLibActivity
* @param imageUri
图片的Uri
* @param imageWidth 想要被缩放到的target图片宽度，我会根据此宽度和原图的比例，去计算target图片高度
* @param callback
回调监听
*/
public static void createScaledBitmap(final BaseLibActivity activity, final Uri imageUri, int imageWidth, final MyCallback callback) {
final String imagePath = getPathByUri(activity, imageUri);
createScaledBitmap(activity, imagePath, imageWidth, callback);
}
/**
* 返回bitmap 所占内存的大小
*/
public static int getBitmapBytes(Bitmap bitmap) {
return bitmap.getByteCount();
}
}

回调接口类：

public interface MyCallback {
void onPrepare();
void onSucceed(Object object);
void onError();
}

使用方法：


BitmapUtils.createScaledBitmap(getContext(),imageUri,700, new MyCallback() {
@Override
public void onPrepare() {
}
@Override
public void onSucceed(Object object) {
String imagePath = (String) object;
}
@Override
public void onError() {
}
});
BitmapUtils.createScaledBitmap(getContext(),"/scard/images/13343222.png",700, new MyCallback() {
@Override
public void onPrepare() {
}
@Override
public void onSucceed(Object object) {
String imagePath = (String) object;
}
@Override
public void onError() {
}
});