Develop Reference

How to avoid image from distort in Android?

I want to reuse size of bitmap when I send to server as base64. For example, original image size is 1.2 MB so I have to resize it to 50KB (server limit side). The way make image distort sometimes. I have read [1] and [2], but it didn't help.
The problem is some image become distort after resize.
Here is my code:
private String RescaleImage(String bitmap, int size) {
try {
if ((float) bitmap.getBytes().length / 1000 <= Constants.PROFILE_IMAGE_LIMITED_SIZE) {
return bitmap;
} else {
//Rescale
Log.d("msg", "rescale size : " + size);
size -= 1;
bitmap = BitmapBase64Util.encodeToBase64(Bitmap.createScaledBitmap(decodeBase64(bitmap), size, size, false));
return RescaleImage(bitmap, size);
}
} catch (Exception e) {
return bitmap;
}
}
encodingToBase64:
public static String encodeToBase64(Bitmap image) {
Log.d(TAG, "encoding image");
String result = "";
if (image != null) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
image.compress(Bitmap.CompressFormat.JPEG, 100, baos);
byte[] b = baos.toByteArray();
result = Base64.encodeToString(b, Base64.DEFAULT);
Log.d(TAG, result);
return result;
}
return result;
}
Image is cropped before resize. Size after cropped is 300 x 300
My question is:
How to reuse image size to 50KB, keep same ratio and avoid distort?

You pass the the same width and height in Bitmap.createScaledBitmap(decodeBase64(bitmap), size, size, false). Unless your bitmaps are squares you have to specify the right widht and height, otherwise your image gets distorted based on the original aspect ratio. I think something like this would work:
Bitmap scaledBitmap = Bitmap.createScaledBitmap(decodeBase64(bitmap);
bitmap = BitmapBase64Util.encodeToBase64(scaledBitmap, scaledBitmap.getWidth(), size.getHeight(), false);
If you need compression to reduce the size use this [Edit: You have done this]:
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] byteArray = stream.toByteArray();

I update my code and it work better now.
-- FixED --
Instead of resize the bitmap string continuously, I use the orignal bitmap that is used before resize.
private String RescaleImage(String bitmap, Bitmap origin_bitmap, int size) {
try {
if ((float) bitmap.getBytes().length / 1000 <= Constants.PROFILE_IMAGE_LIMITED_SIZE) {
return bitmap;
} else {
//Rescale
Log.d("msg", "rescale size : " + size);
size -= 1;
bitmap = BitmapBase64Util.encodeToBase64(Bitmap.createScaledBitmap(origin_bitmap, size, size, false));
return RescaleImage(bitmap, origin_bitmap, size);
}
} catch (Exception e) {
return bitmap;
}
}
Also, use this code when decode to reuse distortion. Bad image quality after resizing/scaling bitmap.
If there are better fix, I always welcome in order to improve.

Dealing with large bitmap onPictureTaken android

My app is an OCR app base on Tesseract. It will do OCR task from camera picture. Users can take many pictures and put them into an OCR queue. To get more accuracy, I want to keep high quality image (I choose min size is 1024 x 768 (maybe larger in future), JPEG, 100% quality). When users take many pictures, there are three things to do:
Save the image data byte[] to file and correct EXIF.
Correct the image orientation base on device's orientation. I know there are some answers that said the image which comes out of the camera is not oriented automatically, have to correct it from file, like here and here. I'm not sure about it, I can setup the camera preview orientation correctly, but the image results aren't correct.
Load bitmap from taken picture, convert it to grayscale and save to another file for OCR task.
And here is my try:
public static boolean saveBitmap(byte[] bitmapData, int orientation, String imagePath, String grayScalePath) throws Exception {
Boolean rotationSuccess = false;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap originalBm = null;
Bitmap bitmapRotate = null;
Bitmap grayScale = null;
FileOutputStream outStream = null;
try {
// save directly from byte[] to file
saveBitmap(bitmapData, imagePath);
// down sample
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(imagePath, options);
int sampleSize = calculateInSampleSize(options, Config.CONFIG_IMAGE_WIDTH, Config.CONFIG_IMAGE_HEIGHT);
options.inJustDecodeBounds = false;
options.inSampleSize = sampleSize;
originalBm = BitmapFactory.decodeFile(imagePath, options);
Matrix mat = new Matrix();
mat.postRotate(orientation);
bitmapRotate = Bitmap.createBitmap(originalBm, 0, 0, originalBm.getWidth(), originalBm.getHeight(), mat, true);
originalBm.recycle();
originalBm = null;
outStream = new FileOutputStream(new File(imagePath));
bitmapRotate.compress(CompressFormat.JPEG, 100, outStream);
// convert to gray scale
grayScale = UIUtil.convertToGrayscale(bitmapRotate);
saveBitmap(grayScale, grayScalePath);
grayScale.recycle();
grayScale = null;
bitmapRotate.recycle();
bitmapRotate = null;
rotationSuccess = true;
} catch (OutOfMemoryError e) {
e.printStackTrace();
System.gc();
} finally {
if (originalBm != null) {
originalBm.recycle();
originalBm = null;
}
if (bitmapRotate != null) {
bitmapRotate.recycle();
bitmapRotate = null;
}
if (grayScale != null) {
grayScale.recycle();
grayScale = null;
}
if (outStream != null) {
try {
outStream.close();
} catch (IOException e) {
}
outStream = null;
}
}
Log.d(TAG,"save completed");
return rotationSuccess;
}
Save to file directly from byte[]
public static void saveBitmap(byte[] bitmapData, String fileName) throws Exception {
File file = new File(fileName);
FileOutputStream fos;
BufferedOutputStream bos = null;
try {
final int bufferSize = 1024 * 4;
fos = new FileOutputStream(file);
bos = new BufferedOutputStream(fos, bufferSize);
bos.write(bitmapData);
bos.flush();
} catch (Exception ex) {
throw ex;
} finally {
if (bos != null) {
bos.close();
}
}
}
Calculate scale size
public 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) {
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) > reqHeight && (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
When save complete, this image is loaded into thumbnail image view by UIL. The problem is the save task is very slow (wait some second before save complete and load into view), and sometime I got OutOfMemory exception. Is there any ideas to reduce the save task and avoid OutOfMemory exception?
Any help would be appreciated!
P/S: the first time I try to convert byte[] to bitmap instead of save to file, and then rotate and convert to grayscale, but I still got above issues.
Update: here is the grayscale bitmap process:
public static Bitmap convertToGrayscale(Bitmap bmpOriginal) {
int width, height;
height = bmpOriginal.getHeight();
width = bmpOriginal.getWidth();
Bitmap bmpGrayscale = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bmpGrayscale);
Paint paint = new Paint();
ColorMatrix cm = new ColorMatrix();
cm.setSaturation(0);
ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);
paint.setColorFilter(f);
c.drawBitmap(bmpOriginal, 0, 0, paint);
return bmpGrayscale;
}
The OutOfMemory exception seldom occurred (just a few times) and I can't reproduce it now.

Update:
Since you're still saying that the method takes too long time I would define a callback interface
interface BitmapCallback {
onBitmapSaveComplete(Bitmap bitmap, int orientation);
onBitmapRotateAndBWComlete(Bitmap bitmap);
}
Let your activity implement the above interface and convert the byte[] to bitmap in top of your saveBitmap method and fire the callback, before the first call to save. Rotate the imageView based on the orientation parameter and set a black/white filter on the imageView to fool the user into thinking that the bitmap is black and white (do this in your activity). See to that the calls are done on main thread (the calls to imageView). Keep your old method as you have it. (all steps need to be done anyway) Something like:
public static boolean saveBitmap(byte[] bitmapData, int orientation, String imagePath, String grayScalePath, BitmapCallback callback) throws Exception {
Boolean rotationSuccess = false;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap originalBm = null;
Bitmap bitmapRotate = null;
Bitmap grayScale = null;
FileOutputStream outStream = null;
try {
// TODO: convert byte to Bitmap, see to that the image is not larger than your wanted size (1024z768)
callback.onBitmapSaveComplete(bitmap, orientation);
// save directly from byte[] to file
saveBitmap(bitmapData, imagePath);
.
.
// same as old
.
.
saveBitmap(grayScale, grayScalePath);
// conversion done callback with the real fixed bitmap
callback.onBitmapRotateAndBWComlete(grayScale);
grayScale.recycle();
grayScale = null;
bitmapRotate.recycle();
bitmapRotate = null;
rotationSuccess = true;
How do you setup your camera? What might be causing the long execution time in the first saveBitmap call, could be that you are using the default camera picture size settings and not reading the supported camera picture size and choosing best fit for your 1024x768 image needs. You might be taking big mpixel images and saving such, but in the end need you need < 1 mpixles (1024x768). Something like this in code:
Camera camera = Camera.open();
Parameters params = camera.getParameters();
List sizes = params.getSupportedPictureSizes();
// Loop camera sizes and find best match, larger than 1024x768
This is probably where you will save most of the time if you are not doing this already. And do it only once, during some initialization phase.
Increase the buffer to 8k in saveBitmap, change the 1024*4 to 1024*8, this would increase the performance at least, not save any significant time perhaps.
To save/reuse bitmap memory consider using inBitmap field, if you have a post honeycomb version, of BitmapFactory.Options and set that field to point to bitmapRotate bitmap and send options down to your convertToGrayscale method to not need allocating yet another bitmap down in that method. Read about inBitmap here: inBitmap

getting Image ThumbNail in Android

I need Thumbnail of an image . I only know about the name of image which is stored in SD card . Can anyone help me.

Try this.
final int THUMBSIZE = 64;
Bitmap ThumbImage = ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(imagePath),
THUMBSIZE, THUMBSIZE);
Refer this for more details.

Using MediaStore.Images.Thumbnails you can query and get two kinds of thumbnails: MINI_KIND: 512 x 384 thumbnail MICRO_KIND: 96 x 96 thumbnail.
The advantage of using this call is that the thumbnails are cached by the MediaStore. So retrieval would be faster if the thumbnail was previously created.

byte[] imageData = null;
try
{
final int THUMBNAIL_SIZE = 64;
FileInputStream fis = new FileInputStream(fileName);
Bitmap imageBitmap = BitmapFactory.decodeStream(fis);
Float width = new Float(imageBitmap.getWidth());
Float height = new Float(imageBitmap.getHeight());
Float ratio = width/height;
imageBitmap = Bitmap.createScaledBitmap(imageBitmap, (int)(THUMBNAIL_SIZE * ratio), THUMBNAIL_SIZE, false);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
imageBitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
imageData = baos.toByteArray();
}
catch(Exception ex) {
}

If you like HQ thumbnails, so use [RapidDecoder][1] library. It is simple as follow:
import rapid.decoder.BitmapDecoder;
...
Bitmap bitmap = BitmapDecoder.from(getResources(), R.drawable.image)
.scale(width, height)
.useBuiltInDecoder(true)
.decode();
Don't forget to use builtin decoder if you want to scale down less than 50% and a HQ result.

Loading big image to bitmap in android

Hi i am using below code to load images from sdcard, it is running correctly,
Bitmap picture=BitmapFactory.decodeFile("/sdcard...");
or
Bitmap picture= BitmapFactory.decodeByteArray(byte[]..);
The byte[] array contains bytes read from sdcard by using FileInputstream and is not null. Both of above codes work fine. The problem is that they dont work for images that are larger e.g. i have an image of 1.8 mb in size. My app crashes while decoding the image. Any method used for larges image fails.
Any solution plz thakns.

Try to create purgeable Bitmap.
byte[] data = ...(read byte array from file)
BitmapFactory.Options opt = new BitmapFactory.Options();
opt.inPurgeable = true;
Bitmap picture = BitmapFactory.decodeByteArray(data, 0, data.length, opt);

Use the below code to resize the image any size you need..
Bitmap picture=BitmapFactory.decodeFile("/sdcard...");
int width = picture.getWidth();
int height = picture.getWidth();
float aspectRatio = (float) width / (float) height;
int newWidth = 70;
int newHeight = (int) (70 / aspectRatio);
picture= Bitmap.createScaledBitmap(picture, newWidth, newHeight, true);

The tutorial at http://developer.android.com/training/displaying-bitmaps/load-bitmap.html explains how to load large images into a Bitmap without encountering the dreaded OutOfMemoryException.

The Android VM has memory limitation which limits the size of the images decodable. To display the resixed images in an image view the following code could be used.
decode_options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(temp,decode_options); //This will just fill the output parameters
if(decode_options.outWidth > image_width
|| decode_options.outHeight > image_height)
{
float scale_width,scale_height;
scale_width = ((float)decode_options.outWidth) / image_width;
scale_param = scale_width;
scale_height = ((float)decode_options.outHeight) / image_height;
if(scale_param < scale_height)
scale_param = scale_height;
}
decode_options.inJustDecodeBounds = false;
decode_options.inSampleSize = (int)(scale_param + 1);
decode_options.inPreferredConfig = Bitmap.Config.ARGB_8888;
decoded_data =
BitmapFactory.decodeFile(temp,decode_options);

Android how to create runtime thumbnail

I have a large sized image. At runtime, I want to read the image from storage and scale it so that its weight and size gets reduced and I can use it as a thumbnail. When a user clicks on the thumbnail, I want to display the full-sized image.

Try this
Bitmap ThumbImage = ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(imagePath), THUMBSIZE, THUMBSIZE);
This Utility is available from API_LEVEl 8. [Source]

My Solution
byte[] imageData = null;
try
{
final int THUMBNAIL_SIZE = 64;
FileInputStream fis = new FileInputStream(fileName);
Bitmap imageBitmap = BitmapFactory.decodeStream(fis);
imageBitmap = Bitmap.createScaledBitmap(imageBitmap, THUMBNAIL_SIZE, THUMBNAIL_SIZE, false);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
imageBitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
imageData = baos.toByteArray();
}
catch(Exception ex) {
}

The best solution I found is the following. Compared with the other solutions this one does not need to load the full image for creating a thumbnail, so it is more efficient!
Its limit is that you can not have a thumbnail with exact width and height but the solution as near as possible.
File file = ...; // the image file
Options bitmapOptions = new Options();
bitmapOptions.inJustDecodeBounds = true; // obtain the size of the image, without loading it in memory
BitmapFactory.decodeFile(file.getAbsolutePath(), bitmapOptions);
// find the best scaling factor for the desired dimensions
int desiredWidth = 400;
int desiredHeight = 300;
float widthScale = (float)bitmapOptions.outWidth/desiredWidth;
float heightScale = (float)bitmapOptions.outHeight/desiredHeight;
float scale = Math.min(widthScale, heightScale);
int sampleSize = 1;
while (sampleSize < scale) {
sampleSize *= 2;
}
bitmapOptions.inSampleSize = sampleSize; // this value must be a power of 2,
// this is why you can not have an image scaled as you would like
bitmapOptions.inJustDecodeBounds = false; // now we want to load the image
// Let's load just the part of the image necessary for creating the thumbnail, not the whole image
Bitmap thumbnail = BitmapFactory.decodeFile(file.getAbsolutePath(), bitmapOptions);
// Save the thumbnail
File thumbnailFile = ...;
FileOutputStream fos = new FileOutputStream(thumbnailFile);
thumbnail.compress(Bitmap.CompressFormat.JPEG, 90, fos);
fos.flush();
fos.close();
// Use the thumbail on an ImageView or recycle it!
thumbnail.recycle();

Here is a more complete solution to scaling down a Bitmap to thumbnail size. It expands on the Bitmap.createScaledBitmap solution by maintaining the aspect ratio of the images and also padding them to the same width so that they look good in a ListView.
Also, it would be best to do this scaling once and store the resulting Bitmap as a blob in your Sqlite database. I have included a snippet on how to convert the Bitmap to a byte array for this purpose.
public static final int THUMBNAIL_HEIGHT = 48;
public static final int THUMBNAIL_WIDTH = 66;
imageBitmap = BitmapFactory.decodeByteArray(mImageData, 0, mImageData.length);
Float width = new Float(imageBitmap.getWidth());
Float height = new Float(imageBitmap.getHeight());
Float ratio = width/height;
imageBitmap = Bitmap.createScaledBitmap(imageBitmap, (int)(THUMBNAIL_HEIGHT*ratio), THUMBNAIL_HEIGHT, false);
int padding = (THUMBNAIL_WIDTH - imageBitmap.getWidth())/2;
imageView.setPadding(padding, 0, padding, 0);
imageView.setImageBitmap(imageBitmap);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
imageBitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
byte[] byteArray = baos.toByteArray();

Use BitmapFactory.decodeFile(...) to get your Bitmap object and set it to an ImageView with ImageView.setImageBitmap().
On the ImageView set the layout dimensions to something small, eg:
android:layout_width="66dip" android:layout_height="48dip"
Add an onClickListener to the ImageView and launch a new activity, where you display the image in full size with
android:layout_width="wrap_content" android:layout_height="wrap_content"
or specify some larger size.

/**
* Creates a centered bitmap of the desired size.
*
* #param source original bitmap source
* #param width targeted width
* #param height targeted height
* #param options options used during thumbnail extraction
*/
public static Bitmap extractThumbnail(
Bitmap source, int width, int height, int options) {
if (source == null) {
return null;
}
float scale;
if (source.getWidth() < source.getHeight()) {
scale = width / (float) source.getWidth();
} else {
scale = height / (float) source.getHeight();
}
Matrix matrix = new Matrix();
matrix.setScale(scale, scale);
Bitmap thumbnail = transform(matrix, source, width, height,
OPTIONS_SCALE_UP | options);
return thumbnail;
}

I found an easy way to do this
Bitmap thumbnail = ThumbnailUtils.extractThumbnail(BitmapFactory.decodeFile(mPath),200,200)
Syntax
Bitmap thumbnail = ThumbnailUtils.extractThumbnail(Bitmap source,int width,int height)
OR
use Picasso dependancy
compile 'com.squareup.picasso:picasso:2.5.2'
Picasso.with(context)
.load("file:///android_asset/DvpvklR.png")
.resize(50, 50)
.into(imageView2);
Reference Picasso

If you want high quality result, so use [RapidDecoder][1] library. It is simple as follow:
import rapid.decoder.BitmapDecoder;
...
Bitmap bitmap = BitmapDecoder.from(getResources(), R.drawable.image)
.scale(width, height)
.useBuiltInDecoder(true)
.decode();
Don't forget to use builtin decoder if you want to scale down less than 50% and a HQ result.

This answer is based on the solution presented in https://developer.android.com/topic/performance/graphics/load-bitmap.html (without using of external libraries) with some changes by me to make its functionality better and more practical.
Some notes about this solution:
It is assumed that you want to keep the aspect ratio. In other words:
finalWidth / finalHeight == sourceBitmap.getWidth() / sourceBitmap.getWidth() (Regardless of casting and rounding issues)
It is assumed that you have two values (maxWidth & maxHeight) that you want any of the dimensions of your final bitmap doesn't exceed its corresponding value. In other words:
finalWidth <= maxWidth && finalHeight <= maxHeight
So minRatio has been placed as the basis of calculations (See the implementation). UNLIKE the basic solution that has placed maxRatio as the basis of calculations in actual. Also, the calculation of inSampleSize has been so much better (more logic, brief and efficient).
It is assumed that you want to (at least) one of the final dimensions has exactly the value of its corresponding maxValue (each one was possible, by considering the above assumptions). In other words:
finalWidth == maxWidth || finalHeight == maxHeight
The final additional step in compare to the basic solution (Bitmap.createScaledBitmap(...)) is for this "exactly" constraint. The very important note is you shouldn't take this step at first (like the accepted answer), because of its significant consumption of memory in case of huge images!
It is for decoding a file. You can change it like the basic solution to decode a resource (or everything that BitmapFactory supports).
The implementation:
public static Bitmap decodeSampledBitmap(String pathName, int maxWidth, int maxHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(pathName, options);
final float wRatio_inv = (float) options.outWidth / maxWidth,
hRatio_inv = (float) options.outHeight / maxHeight; // Working with inverse ratios is more comfortable
final int finalW, finalH, minRatio_inv /* = max{Ratio_inv} */;
if (wRatio_inv > hRatio_inv) {
minRatio_inv = (int) wRatio_inv;
finalW = maxWidth;
finalH = Math.round(options.outHeight / wRatio_inv);
} else {
minRatio_inv = (int) hRatio_inv;
finalH = maxHeight;
finalW = Math.round(options.outWidth / hRatio_inv);
}
options.inSampleSize = pow2Ceil(minRatio_inv); // pow2Ceil: A utility function that comes later
options.inJustDecodeBounds = false; // Decode bitmap with inSampleSize set
return Bitmap.createScaledBitmap(BitmapFactory.decodeFile(pathName, options),
finalW, finalH, true);
}
/**
* #return the largest power of 2 that is smaller than or equal to number.
* WARNING: return {0b1000000...000} for ZERO input.
*/
public static int pow2Ceil(int number) {
return 1 << -(Integer.numberOfLeadingZeros(number) + 1); // is equivalent to:
// return Integer.rotateRight(1, Integer.numberOfLeadingZeros(number) + 1);
}
Sample Usage, in case of you have an imageView with a determined value for layout_width (match_parent or a explicit value) and a indeterminate value for layout_height (wrap_content) and instead a determined value for maxHeight:
imageView.setImageBitmap(decodeSampledBitmap(filePath,
imageView.getWidth(), imageView.getMaxHeight()));