Develop Reference

Compressing an image to meet a file size limit (Android)

I've implemented the below code to scale an image down, with respect to the aspect ratio (by proportionally decreasing height/width with respect to one another).. This will definitely help to reduce the size of the images uploaded to my backend, but this does not take into account the resolution of the images. I want to set a hard image limit, say 800Kb, and if the image is greater than 800Kb after resizing, then compress to a point at which it is less than 800Kb.
Anyone have any experience doing something like this? I'm curious what relationship lies between the quality argument passed into the Bitmap.Compress method and how much file size is shaven off per percentage quality - If i could obtain this information, I believe I can reach my goal.
Thanks for any help ahead of time, my current code is below, maybe it will help others heading in this direction in the future.
public static void uploadImage(String url, File file, Callback callback, Context context,
IMAGE_PURPOSE purpose) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(file.getAbsolutePath(), options);
int maxWidth = 0;
int maxHeight = 0;
int maxSize = 0;
switch(purpose){
case PROFILE:
maxWidth = Constants.MAX_PROFILE_IMAGE_WIDTH;
maxHeight = Constants.MAX_PROFILE_IMAGE_HEIGHT;
maxSize = Constants.MAX_PROFILE_IMAGE_SIZE;
break;
case UPLOAD:
maxWidth = Constants.MAX_UPLOAD_IMAGE_WIDTH;
maxHeight = Constants.MAX_UPLOAD_IMAGE_HEIGHT;
maxSize = Constants.MAX_UPLOAD_IMAGE_SIZE;
break;
}
int newWidth = bitmap.getWidth();
int newHeight = bitmap.getHeight();
// Make sure the width is OK
if(bitmap.getWidth() > maxWidth){
// Find out how much the picture had to shrink to get to our max defined width
float shrinkCoeff = ((float)(bitmap.getWidth() - maxWidth) / (float)bitmap.getWidth());
newWidth = maxWidth;
// Shrink the height by the same amount to maintain aspect ratio
newHeight = bitmap.getHeight() - (int)((float)bitmap.getHeight() * shrinkCoeff);
}
// Make sure the height is OK
if(newHeight > maxHeight){
// Find out how much the picture had to shrink to get to our max defined width
float shrinkCoeff = ((newHeight - maxHeight) / newHeight);
newHeight = maxHeight;
// Shrink the width by the same amount to maintain aspect ratio
newWidth = newWidth - (int)((float)newWidth * shrinkCoeff);
}
Bitmap resized = Bitmap.createScaledBitmap(bitmap, newWidth, newHeight, true);
// Get the image in bytes
ByteArrayOutputStream bos = new ByteArrayOutputStream();
resized.compress(Bitmap.CompressFormat.JPEG, 100, bos);
byte[] imageBytes = bos.toByteArray();
// If the size on disk is too big, reduce the quality
if(imageBytes.length > maxSize){
// Compress image here to get to maxSize
}

Android - Does an ImageView resizes the image (and doesn't save the original)?

Quite a simple questions, can't find an answer..
I'm asking in order to know if even though the ImageView shows a smaller version of the original image - does it still use the full memory size of the original .. ?
(I refer to an image which was loaded from the SD-card and not from resources)

Yes, it will use the original size. You have to resize all your bitmaps before assign then to an ImageView, otherwise you will have a lot of problems with Out Of Memory Error.
You should also calculate the final size of you ImageView and resize the Bitmap.
Some code to get you going.
private static Bitmap createBitmap(#NonNull String filePath, int width )
{
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filePath , options );
// Getting original image properties
int imageHeight = options.outHeight;
int imageWidth = options.outWidth;
int scale = -1;
if ( imageWidth < imageHeight ) {
scale = Math.round( imageHeight / width );
} else {
scale = Math.round(imageWidth / width);
}
if ( scale <= 0 )
scale = 1;
options.inSampleSize = scale;
options.inJustDecodeBounds = false;
// Create a resized bitmap
Bitmap scaledBitmap = BitmapFactory.decodeFile(filePath , options);
return scaledBitmap;
}
You should also consider:
Maintain all Bitmap operations outside the main Thread.
Handle Concurrency correctly
Make use of some open source lib, like this one

center Crop Image In proper size to set on ImageView

I am using camera API to take picture i have to open camera in different sizes according to my Image view size. I am following the sample project which we get inside Android sdk/sample/adroid-18 at the name "ApiDemo" the thing i have changed is not set camera on setcontentview. I have set the camera on Frame Layout. at first my camera preview was starched so i got the camera OptimalPreviewSize and make FrameLayout parameter width and height as wrap-content.Now the camera preview is smaller then ImageView (The size i want). If i make the size of FrameLayout parameter as match-parent then camera View is stretch.How to resolve this issue.
find this link for more specification. Android camera preview look strange
UPDATE
My camera preview size is fine now i use the on Layout method the idea was i have the bigger layout then my ImageView and now camera preview is looking good.
Now the Problem I am facing is set the image of proper size for this I have to center crop and scale in same size in like my ImageView.this Image i get by TakePicture method and saved in sdcard.
For this I am using this method:-
public Bitmap scaleCenterCrop(Bitmap source, int newHeight, int newWidth) {
int sourceWidth = source.getWidth();
int sourceHeight = source.getHeight();
// Compute the scaling factors to fit the new height and width, respectively.
// To cover the final image, the final scaling will be the bigger
// of these two.
float xScale = (float) newWidth / sourceWidth;
float yScale = (float) newHeight / sourceHeight;
float scale = Math.max(xScale, yScale);
// Now get the size of the source bitmap when scaled
float scaledWidth = scale * sourceWidth;
float scaledHeight = scale * sourceHeight;
// Let's find out the upper left coordinates if the scaled bitmap
// should be centered in the new size give by the parameters
float left = (newWidth - scaledWidth) / 2;
float top = (newHeight - scaledHeight) / 2;
// The target rectangle for the new, scaled version of the source bitmap will now
// be
RectF targetRect = new RectF(left+50, top, left + scaledWidth, top + scaledHeight+50);
// RectF targetRect = new RectF(0, 0, newWidth, newHeight/2);
// Finally, we create a new bitmap of the specified size and draw our new,
// scaled bitmap onto it.
Bitmap dest = Bitmap.createBitmap(newWidth, newHeight, source.getConfig());
Canvas canvas = new Canvas(dest);
canvas.drawBitmap(source, null, targetRect, null);
return dest;
}
But the result image quality is not good.Height Corners are cutting from top and bottom, and result image quality is not good.Pixels are stretching.
Don't tell me to use scaleType=Center_crop i can't use it in my case,and don't want to show cropping frame to user,this all process should not show on UI.
UPDATE
I used blow method for crop image from center and scale according to my imageView size
Bitmap dstBmp = ThumbnailUtils.extractThumbnail(source, newWidth, newHeight);
But the bitmap i got is not looking same the camera preview shown on FrameLayout. because camera preview is big.I think these code cropped the large area.
I tried to reduce the width and change the height but not getting the same cropped image in which ratio i want.
One more idea i have after picture crop a last image frame set automatically on FrameLayout. can we get that set frame from Frame Layout. How is this possible?
Here is question like this How to retrieve the visible part of a SurfaceView in Android do any one have solution.
I want to achieve this by this line ThumbnailUtils.extractThumbnail(source, newWidth, newHeight);and by this line i am getting src like image described in diagram .
What to change in this line exactly ????

Center crop an image may be help you this.
public Bitmap scaleCenterCrop(Bitmap source, int newHeight, int newWidth) {
int sourceWidth = source.getWidth();
int sourceHeight = source.getHeight();
// Compute the scaling factors to fit the new height and width, respectively.
// To cover the final image, the final scaling will be the bigger
// of these two.
float xScale = (float) newWidth / sourceWidth;
float yScale = (float) newHeight / sourceHeight;
float scale = Math.max(xScale, yScale);
// Now get the size of the source bitmap when scaled
float scaledWidth = scale * sourceWidth;
float scaledHeight = scale * sourceHeight;
// Let's find out the upper left coordinates if the scaled bitmap
// should be centered in the new size give by the parameters
float left = (newWidth - scaledWidth) / 2;
float top = (newHeight - scaledHeight) / 2;
// The target rectangle for the new, scaled version of the source bitmap will now
// be
RectF targetRect = new RectF(left, top, left + scaledWidth, top + scaledHeight);
// Finally, we create a new bitmap of the specified size and draw our new,
// scaled bitmap onto it.
Bitmap dest = Bitmap.createBitmap(newWidth, newHeight, source.getConfig());
Canvas canvas = new Canvas(dest);
canvas.drawBitmap(source, null, targetRect, null);
return dest;
}

#Akanksha Please use this below code, you just need to pass the path of the saved image, and the hight and width of our imageview. This code works perfectly for me.
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
public class ImageHandler {
/**
* Decode and sample down a bitmap from a file to the requested width and
* height.
*
* #param filename
* The full path of the file to decode
* #param reqWidth
* The requested width of the resulting bitmap
* #param reqHeight
* The requested height of the resulting bitmap
* #return A bitmap sampled down from the original with the same aspect
* ratio and dimensions that are equal to or greater than the
* requested width and height
*/
public static Bitmap decodeSampledBitmapFromFile(String filename,
int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(filename, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth,
reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(filename, options);
}
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) {
if (width > height) {
inSampleSize = Math.round((float) height / (float) reqHeight);
} else {
inSampleSize = Math.round((float) width / (float) reqWidth);
}
// 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;
}
}
I call this method inside async task because it may take too much UImemory and time
Here is how I call it.
class Asyncing extends AsyncTask {
private int reqWidth;
private int reqHeight;
private ImageView iv;
private String fileName;
private ProgressDialog pd;
public Asyncing(int reqWidth, int reqHeight, ImageView iv,
String fileName) {
super();
this.reqWidth = reqWidth;
this.reqHeight = reqHeight;
this.fileName = fileName;
this.iv = iv;
}
#Override
protected Bitmap doInBackground(String... params) {
return ImageHandler.decodeSampledBitmapFromFile(params[0],
reqWidth, reqHeight);
}
#Override
protected void onPostExecute(Bitmap result) {
iv.setImageBitmap(result);
if (pd.isShowing()) {
pd.setMessage(getString(R.string.completed));
pd.dismiss();
}
super.onPostExecute(result);
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
#Override
protected void onPreExecute() {
pd = ProgressDialog.show(CustomerDetailsActivity.this, "",
getString(R.string.processing_signature));
super.onPreExecute();
}
}
This is how you need to call the asynctask
signedImagePath = data.getExtras().getString("imagePath");
new Asyncing(signature_img.getWidth(), signature_img.getHeight(),
signature_img, "spenTest.png").execute(signedImagePath);
above code is written according to my requirements,you modify it according to yours.

How to resize an image to fit multiple screen densities

I need to add an avatar to a grid item.
I want to know how to handle the resizing of an image chosen from the phones gallery. Once chosen, I imagine some resizing will be needed, to fit it into the grid.
However, do I need to store a resized image for each screen density; store one xhdpi version and scale down for other devices, or be clever in some other way?
The reason is, the app stores this image to a cloud db and other people can download this image. They may see the image on different devices (hence the requirement of different image sizes). How should the managment of this image be processed?

I hope you find the code below useful. It will return image with reqd dimensions with minimum overhead. I have used this many times, works like charm. You can set the required dimension according to target device. Scaling will cause blur in picture but this doesn't.
private Bitmap getBitmap(Uri uri) {
InputStream in = null;
try {
final int IMAGE_MAX_SIZE = 200000; // 0.2MP
in = my_context.getContentResolver().openInputStream(uri);
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true; //request only the dimesion
BitmapFactory.decodeStream(in, null, o);
in.close();
int scale = 1;
while ((o.outWidth * o.outHeight) * (1 / Math.pow(scale, 2)) > IMAGE_MAX_SIZE) {
scale++;
}
Bitmap b = null;
in = my_context.getContentResolver().openInputStream(uri);
if (scale > 1) {
scale--;
// scale to max possible inSampleSize that still yields an image
// larger than target
o = new BitmapFactory.Options();
o.inSampleSize = scale;
b = BitmapFactory.decodeStream(in, null, o);
// resize to desired dimensions
int height = b.getHeight();
int width = b.getWidth();
double y = Math.sqrt(IMAGE_MAX_SIZE
/ (((double) width) / height));
double x = (y / height) * width;
Bitmap scaledBitmap = Bitmap.createScaledBitmap(b, (int) x, (int) y, true);
b.recycle();
b = scaledBitmap;
System.gc();
} else {
b = BitmapFactory.decodeStream(in);
}
in.close();
return b;
} catch (IOException e) {
return null;
}
}

android:scaleType="fitXY"
android:layout_gravity="center"
Will scale an image and center it Size the Size a container to fill_parent with and it should do just that.

You can put your images to drawable (without creating xhdpi,hdpi,mdpi,ldpi...) (global images).
Then you can create 4 same layouts for different screensizes . All of your layout can use the images in your drawable director. So you can resize your image easly.

Set wallpaper in Android

I have image 640*480 in sd card and i want to set it as home screen wallpaper. How Can I do this with small quality loss? With my code Wallpaper has a not good clarity. That's my code:
private void setWallpaper(String filePath) throws IOException{
if(filePath!=null){
// set options for decoding
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inScaled = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
options.inDither = false;
options.inJustDecodeBounds = true;
//get bitmap from filepath
Bitmap bitmap = BitmapFactory.decodeFile(filePath, options);
//get sizes of bitmap
int width = bitmap.getWidth();
int height = bitmap.getHeight();
//get sizes of screen and scale level
Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int newWidth = display.getWidth()*2;
int newHeight = display.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
//set matrix of the scaling
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
//get new bitmap for wallpaper
Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0,
width, height, matrix, true);
//set bitmap as wallpaper
WallpaperManager wallpaperManager = WallpaperManager.getInstance(this);
wallpaperManager.clear();
wallpaperManager.setBitmap(resizedBitmap);
}
}

Any time you scale upwards you're going to suffer quality loss. What size screen are you trying to display this image one? Keep in mind the Android wallpaper dimensions are the height of the screen by 2 times the width of the screen (e.g. 800x480 screen needs a 800x960 image).
My recommendation would be to have a larger image and scale downwards. The quality loss from downsampling is far less noticeable than from upscaling. You could, if space is not an issue, include multiple sizes of the image for differing screen resolutions.