Android 在安卓系统中减少摄像头拍摄图像的大小
在这里，我将从相机中捕获的图像保存在SD卡上。这里，捕获的图像大小大于Android 在安卓系统中减少摄像头拍摄图像的大小,android,image,android-camera,Android,Image,Android Camera,在这里，我将从相机中捕获的图像保存在SD卡上。这里，捕获的图像大小大于1 MB。在保存到SD卡之前，我想将此大小减少到近500kb到600kb。我怎么能这么做 try { Bitmap mPhoto; mPhoto = android.provider.MediaStore.Images.Media.getBitmap(cr, CheckInGallery.mUri); ByteArrayOutputStr
1 MBtry
{
Bitmap mPhoto;
mPhoto = android.provider.MediaStore.Images.Media.getBitmap(cr, CheckInGallery.mUri);
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
mPhoto.compress(Bitmap.CompressFormat.PNG, 100, bytes);
File direct = new File(Environment.getExternalStorageDirectory() + "/RetailRun");
String mydate = java.text.DateFormat.getDateTimeInstance().format(Calendar.getInstance().getTime());
Toast.makeText(getBaseContext(), "Time :" + mydate, 5000).show();
if(!direct.exists())
{
direct.mkdir();
File file = new File(Environment.getExternalStorageDirectory()+File.separator + "/MyImage/image" + mydate +".jpg");
file.createNewFile();
FileOutputStream fo = new FileOutputStream(file);
fo.write(bytes.toByteArray());
fo.close();
}
else
{
File file = new File(Environment.getExternalStorageDirectory()+File.separator + "/MyImage/image" + mydate +".jpg");
file.createNewFile();
FileOutputStream fo = new FileOutputStream(file);
fo.write(bytes.toByteArray());
fo.close();
}
}
catch (Exception e)
{
Toast.makeText(this, e.getMessage(), Toast.LENGTH_SHORT).show();
}
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize=2; //4, 8, etc. the more value, the worst quality of image
Bitmap bmp=BitmapFactory.decodeStream(getContentResolver().openInputStream(CheckInGallery.mUri), null, options);
bmp.compress(Bitmap.CompressFormat.PNG, 70, bytes);
设置位图的高度和宽度是特定于设备的
@SuppressLint("NewApi")
public static int getDeviceWidth(Activity activity) {
int deviceWidth = 0;
Point size = new Point();
WindowManager windowManager = activity.getWindowManager();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
windowManager.getDefaultDisplay().getSize(size);
deviceWidth = size.x;
} else {
Display display = windowManager.getDefaultDisplay();
deviceWidth = display.getWidth();
}
return deviceWidth;
}
@SuppressLint("NewApi")
public static int getDeviceHeight(Activity activity) {
int deviceHeight = 0;
Point size = new Point();
WindowManager windowManager = activity.getWindowManager();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
windowManager.getDefaultDisplay().getSize(size);
deviceHeight = size.y;
} else {
Display display = windowManager.getDefaultDisplay();
deviceHeight = display.getHeight();
}
return deviceHeight;
}
这种方法可以减小图像大小。这在我的项目中很有用。在阅读了其他答案后，没有找到我想要的，下面是我获取适当缩放位图的方法。这是对普拉布答案的改编
**Reduce captured image size and save ..in kb**
String imagePath = context.getFilesDir().getAbsolutePath() + File.separatorChar + "FolderName" + File.separatorChar + "ImageFolder" + File.separatorChar + imageName + ".jpg";
File prescImagefile = new File(imagePath);
try
{
if (prescImagefile.exists() == false)
{
prescImagefile.getParentFile().mkdirs();
prescImagefile.createNewFile();
}
}
catch (IOException e)
{
// Log.e("TAG", "Could not create file.", e);
}
if (prescImagefile != null)
{
mCapturedImageURI = Uri.fromFile(prescImagefile);
if (mCapturedImageURI != null)
{
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
if (resultCode == RESULT_OK)
{
if (requestCode == CAMERA_REQUEST)
{
try
{
String path = mCapturedImageURI.getPath();
StoreImage(context, mCapturedImageURI, prescImagefile);
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
}
public static void StoreImage(Context mContext, Uri imgUri, File imageDir)
{
Bitmap bm = null;
try
{
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
// bm = Media.getBitmap(mContext.getContentResolver(), imageLoc);
bm = BitmapFactory.decodeStream(mContext.getContentResolver().openInputStream(imgUri), null, options);
FileOutputStream out = new FileOutputStream(imageDir);
bm.compress(Bitmap.CompressFormat.JPEG, 20, out);
bm.recycle();
}
catch (Exception e)
{
e.printStackTrace();
}
}
public saveScaledPhotoToFile() {
//Convert your photo to a bitmap
Bitmap photoBm = (Bitmap) "your Bitmap image";
//get its orginal dimensions
int bmOriginalWidth = photoBm.getWidth();
int bmOriginalHeight = photoBm.getHeight();
double originalWidthToHeightRatio = 1.0 * bmOriginalWidth / bmOriginalHeight;
double originalHeightToWidthRatio = 1.0 * bmOriginalHeight / bmOriginalWidth;
//choose a maximum height
int maxHeight = 1024;
//choose a max width
int maxWidth = 1024;
//call the method to get the scaled bitmap
photoBm = getScaledBitmap(photoBm, bmOriginalWidth, bmOriginalHeight,
originalWidthToHeightRatio, originalHeightToWidthRatio,
maxHeight, maxWidth);
/**********THE REST OF THIS IS FROM Prabu's answer*******/
//create a byte array output stream to hold the photo's bytes
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
//compress the photo's bytes into the byte array output stream
photoBm.compress(Bitmap.CompressFormat.JPEG, 40, bytes);
//construct a File object to save the scaled file to
File f = new File(Environment.getExternalStorageDirectory()
+ File.separator + "Imagename.jpg");
//create the file
f.createNewFile();
//create an FileOutputStream on the created file
FileOutputStream fo = new FileOutputStream(f);
//write the photo's bytes to the file
fo.write(bytes.toByteArray());
//finish by closing the FileOutputStream
fo.close();
}
private static Bitmap getScaledBitmap(Bitmap bm, int bmOriginalWidth, int bmOriginalHeight, double originalWidthToHeightRatio, double originalHeightToWidthRatio, int maxHeight, int maxWidth) {
if(bmOriginalWidth > maxWidth || bmOriginalHeight > maxHeight) {
Log.v(TAG, format("RESIZING bitmap FROM %sx%s ", bmOriginalWidth, bmOriginalHeight));
if(bmOriginalWidth > bmOriginalHeight) {
bm = scaleDeminsFromWidth(bm, maxWidth, bmOriginalHeight, originalHeightToWidthRatio);
} else if (bmOriginalHeight > bmOriginalWidth){
bm = scaleDeminsFromHeight(bm, maxHeight, bmOriginalHeight, originalWidthToHeightRatio);
}
Log.v(TAG, format("RESIZED bitmap TO %sx%s ", bm.getWidth(), bm.getHeight()));
}
return bm;
}
private static Bitmap scaleDeminsFromHeight(Bitmap bm, int maxHeight, int bmOriginalHeight, double originalWidthToHeightRatio) {
int newHeight = (int) Math.max(maxHeight, bmOriginalHeight * .55);
int newWidth = (int) (newHeight * originalWidthToHeightRatio);
bm = Bitmap.createScaledBitmap(bm, newWidth, newHeight, true);
return bm;
}
private static Bitmap scaleDeminsFromWidth(Bitmap bm, int maxWidth, int bmOriginalWidth, double originalHeightToWidthRatio) {
//scale the width
int newWidth = (int) Math.max(maxWidth, bmOriginalWidth * .75);
int newHeight = (int) (newWidth * originalHeightToWidthRatio);
bm = Bitmap.createScaledBitmap(bm, newWidth, newHeight, true);
return bm;
}
这里有一个与我的GitHub要点相对应的链接：这就是我的工作原理
public void onImageSelected(){
Uri uri=null; // get the uri of the image result from the intent
try {
Bitmap bitmap = handleSamplingAndRotationBitmap(this, uri);
byte[] bytes = getBytesFromBitmap(bitmap);
//getPresenter.upload(bytes);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* returns an aligned bitmap with size not exceeding the MAX_HEIGHT
* @param context
* @param selectedImage
* @return
* @throws IOException
*/
public Bitmap handleSamplingAndRotationBitmap(Context context, Uri selectedImage)
throws IOException {
Bitmap decoded = getImageSampleOutput(context,selectedImage);
decoded = rotateImageIfRequired(this, decoded, selectedImage);
return decoded;
}
public Bitmap getImageSampleOutput(Context context, Uri selectedImage) throws IOException {
int MAX_HEIGHT = 1200;
int MAX_WIDTH = 1600;
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
InputStream imageStream = context.getContentResolver().openInputStream(selectedImage);
BitmapFactory.decodeStream(imageStream, null, options);
imageStream.close();
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, MAX_WIDTH, MAX_HEIGHT);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
imageStream = context.getContentResolver().openInputStream(selectedImage);
Bitmap img = BitmapFactory.decodeStream(imageStream, null, options);
Bitmap decoded = compressImage(img);
return decoded;
}
/**
* Used to compress the image to prevent any Memory overflows.
* @param bitmap
* @return
*/
public Bitmap compressImage(Bitmap bitmap) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
return BitmapFactory.decodeStream(new ByteArrayInputStream(out.toByteArray()));
}
private static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
// Calculate ratios of height and width to requested height and width
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// Choose the smallest ratio as inSampleSize value, this will guarantee a final image
// with both dimensions larger than or equal to the requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
// This offers some additional logic in case the image has a strange
// aspect ratio. For example, a panorama may have a much larger
// width than height. In these cases the total pixels might still
// end up being too large to fit comfortably in memory, so we should
// be more aggressive with sample down the image (=larger inSampleSize).
final float totalPixels = width * height;
// Anything more than 2x the requested pixels we'll sample down further
final float totalReqPixelsCap = reqWidth * reqHeight * 2;
while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
inSampleSize++;
}
}
return inSampleSize;
}
private static Bitmap rotateImageIfRequired(Context context, Bitmap img, Uri selectedImage) {
// Detect rotation
int rotation = getRotation(context, selectedImage);
if (rotation != 0) {
Matrix matrix = new Matrix();
matrix.postRotate(rotation);
Bitmap rotatedImg = Bitmap.createBitmap(img, 0, 0, img.getWidth(), img.getHeight(), matrix, true);
img.recycle();
return rotatedImg;
} else {
return img;
}
}
/**
* Get the rotation of the last image added.
*
* @param context
* @param selectedImage
* @return
*/
private static int getRotation(Context context, Uri selectedImage) {
int rotation = 0;
ContentResolver content = context.getContentResolver();
Cursor mediaCursor = content.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
new String[]{"orientation", "date_added"},
null, null, "date_added desc");
if (mediaCursor != null && mediaCursor.getCount() != 0) {
while (mediaCursor.moveToNext()) {
rotation = mediaCursor.getInt(0);
break;
}
}
mediaCursor.close();
return rotation;
}
public byte[] getBytesFromBitmap(Bitmap bmp){
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.JPEG,70,stream);
byte[] byteArray = stream.toByteArray();
return byteArray;
}
public void onImageSelected（）{
Uri=null；//从意图中获取图像结果的Uri
试一试{
位图位图=handleSamplingAndRotationBitmap（此，uri）；
字节[]字节=getBytesFromBitmap（位图）；
//getPresenter.upload（字节）；
}捕获（IOE异常）{
e、 printStackTrace（）；
}
}
/**
*返回大小不超过最大高度的对齐位图
*@param上下文
*@param selectedImage
*@返回
*@抛出异常
*/
公共位图句柄采样和旋转位图（上下文上下文，Uri selectedImage）
抛出IOException{
解码位图=getImageSampleOutput（上下文，选择图像）；
解码=旋转图像如果需要（此，解码，选择图像）；
返回解码；
}
公共位图getImageSampleOutput（上下文上下文，Uri selectedImage）引发IOException{
int最大高度=1200；
int MAX_WIDTH=1600；
//使用INJUSTDECBOUNDS首次解码=true检查尺寸
final BitmapFactory.Options=new BitmapFactory.Options（）；
options.inJustDecodeBounds=true；
InputStream imageStream=context.getContentResolver（）.openInputStream（SelecteImage）；
解码流（imageStream，null，选项）；
imageStream.close（）；
//计算样本大小
options.inSampleSize=计算样本大小（选项、最大宽度、最大高度）；
//使用inSampleSize集合解码位图
options.inJustDecodeBounds=false；
imageStream=context.getContentResolver（）.openInputStream（SelecteImage）；
位图img=BitmapFactory.decodeStream（imageStream，null，选项）；
解码位图=压缩图像（img）；
返回解码；
}
/**
*用于压缩图像以防止内存溢出。
*@param位图
*@返回
*/
公共位图压缩图像（位图位图）{
ByteArrayOutputStream out=新建ByteArrayOutputStream（）；
bitmap.compress（bitmap.CompressFormat.JPEG，100，out）；
返回BitmapFactory.decodeStream（新的ByteArrayInputStream（out.toByteArray（））；
}
私有静态int-calculateInSampleSize（BitmapFactory.Options，
输入要求宽度，输入要求高度）{
//图像的原始高度和宽度
最终内部高度=options.outHeight；
最终整数宽度=options.outWidth；
int inSampleSize=1；
如果（高度>要求高度| |宽度>要求宽度）{
//计算高度和宽度与所需高度和宽度的比率
最终内部高度比=数学圆（（浮动）高度/（浮动）要求高度）；
最终整数宽度比=数学圆（（浮动）宽度/（浮动）宽度）；
//选择最小比率作为inSampleSize值，这将保证最终图像
//两个尺寸都大于或等于要求的高度和宽度。
inSampleSize=高度比<宽度比？高度比：宽度比；
//这提供了一些额外的逻辑，以防图像有奇怪的颜色
//宽高比。例如，全景图可能具有更大的宽高比
//宽度大于高度。在这些情况下，总像素可能仍然
//结果是太大而不能舒服地放在记忆中，所以我们应该
//在图像下采样时更具攻击性（=采样尺寸更大）。
最终浮点总数像素=宽度*高度；
//任何超过所需像素2倍的像素，我们将进一步采样
最终浮点totalReqPixelsCap=reqWidth*reqHeight*2；
而（totalPixels/（inSampleSize*inSampleSize）>totalReqPixelsCap）{
inSampleSize++；
}
}
返回样本大小；
}
私有静态位图rotateImageIfRequired（上下文上下文、位图img、Uri selectedImage）{
//检测旋转
int rotation=getRotation（上下文，选择图像）；
如果（旋转！=0）{
矩阵=新矩阵（）；
矩阵。后旋转（旋转）；
Bitmap rotatedImg=Bitmap.createBitmap（img，0，0，img.getWidth（），img.getHeight（），matrix，true）；
img.recycle（）；
返回旋转dIMG；
}否则{
返回img；
}
}
/**
*获取最后添加的图像的旋转。
*
*@param上下文
*@param selectedImage
*@返回
*/
私有静态int-getRotation（上下文，Uri-selectedImage）{
整数旋转=0；
ContentResolver content=context.getContentResolver（）；
游标mediaCursor=content.query（MediaStore.Images.Media.EXTERNAL\u content\u URI，
新字符串[]{“方向”，“添加日期”}，
空，空，“添加说明的日期”）；
if（mediaCursor！=null&&mediaCursor.getCount（）！=0）{
while（mediaCursor.moveToNext（））{
旋转=mediaCursor.getInt（0）；
打破
}
}
mediaCursor.close（）；
返回旋转；
}
公共字节[]getBytesFromBitmap（位图bmp）{
ByteArrayOutputStream=新建ByteArrayOutputStream（）；
bmp.compress（位图.CompressFormat
public void onImageSelected(){
Uri uri=null; // get the uri of the image result from the intent
try {
Bitmap bitmap = handleSamplingAndRotationBitmap(this, uri);
byte[] bytes = getBytesFromBitmap(bitmap);
//getPresenter.upload(bytes);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* returns an aligned bitmap with size not exceeding the MAX_HEIGHT
* @param context
* @param selectedImage
* @return
* @throws IOException
*/
public Bitmap handleSamplingAndRotationBitmap(Context context, Uri selectedImage)
throws IOException {
Bitmap decoded = getImageSampleOutput(context,selectedImage);
decoded = rotateImageIfRequired(this, decoded, selectedImage);
return decoded;
}
public Bitmap getImageSampleOutput(Context context, Uri selectedImage) throws IOException {
int MAX_HEIGHT = 1200;
int MAX_WIDTH = 1600;
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
InputStream imageStream = context.getContentResolver().openInputStream(selectedImage);
BitmapFactory.decodeStream(imageStream, null, options);
imageStream.close();
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, MAX_WIDTH, MAX_HEIGHT);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
imageStream = context.getContentResolver().openInputStream(selectedImage);
Bitmap img = BitmapFactory.decodeStream(imageStream, null, options);
Bitmap decoded = compressImage(img);
return decoded;
}
/**
* Used to compress the image to prevent any Memory overflows.
* @param bitmap
* @return
*/
public Bitmap compressImage(Bitmap bitmap) {
ByteArrayOutputStream out = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
return BitmapFactory.decodeStream(new ByteArrayInputStream(out.toByteArray()));
}
private static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
// Calculate ratios of height and width to requested height and width
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// Choose the smallest ratio as inSampleSize value, this will guarantee a final image
// with both dimensions larger than or equal to the requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
// This offers some additional logic in case the image has a strange
// aspect ratio. For example, a panorama may have a much larger
// width than height. In these cases the total pixels might still
// end up being too large to fit comfortably in memory, so we should
// be more aggressive with sample down the image (=larger inSampleSize).
final float totalPixels = width * height;
// Anything more than 2x the requested pixels we'll sample down further
final float totalReqPixelsCap = reqWidth * reqHeight * 2;
while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
inSampleSize++;
}
}
return inSampleSize;
}
private static Bitmap rotateImageIfRequired(Context context, Bitmap img, Uri selectedImage) {
// Detect rotation
int rotation = getRotation(context, selectedImage);
if (rotation != 0) {
Matrix matrix = new Matrix();
matrix.postRotate(rotation);
Bitmap rotatedImg = Bitmap.createBitmap(img, 0, 0, img.getWidth(), img.getHeight(), matrix, true);
img.recycle();
return rotatedImg;
} else {
return img;
}
}
/**
* Get the rotation of the last image added.
*
* @param context
* @param selectedImage
* @return
*/
private static int getRotation(Context context, Uri selectedImage) {
int rotation = 0;
ContentResolver content = context.getContentResolver();
Cursor mediaCursor = content.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
new String[]{"orientation", "date_added"},
null, null, "date_added desc");
if (mediaCursor != null && mediaCursor.getCount() != 0) {
while (mediaCursor.moveToNext()) {
rotation = mediaCursor.getInt(0);
break;
}
}
mediaCursor.close();
return rotation;
}
public byte[] getBytesFromBitmap(Bitmap bmp){
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.JPEG,70,stream);
byte[] byteArray = stream.toByteArray();
return byteArray;
}