Android make preview from images on web - android

I'm trying to make preview as Thumbnail from images on web before downloading, it means i have more item on RecyclerView and i'm trying to view simple blurred preview from images but i dont know whats solution, i use this below code but i think this code download full image, like with social application such as whatsApp or Telegram how can i make preview image on web and show that to users?
new Thread(new Runnable() {
#Override
public void run() {
//First create a new URL object
URL url = null;
try {
if (checkNetWorkConnection()) {
url = new URL("http://wallpaperwarrior.com/wp-content/uploads/2016/09/Wallpaper-2.jpeg");
//Next create a file, the example below will save to the SDCARD using JPEG format
File file = new File(APP.DIR_APP + APP.IMAGE + "/" + "Wallpaper-2.jpg");
//Next create a Bitmap object and download the image to bitmap
Bitmap bitmap = BitmapFactory.decodeStream(url.openStream());
//Finally compress the bitmap, saving to the file previously created
bitmap.compress(Bitmap.CompressFormat.JPEG, 50, new FileOutputStream(file));
}
} catch (MalformedURLException e) {
e.printStackTrace();
Log.e("Error ", e.getMessage());
} catch (FileNotFoundException e) {
e.printStackTrace();
Log.e("Error ", e.getMessage());
} catch (IOException e) {
e.printStackTrace();
Log.e("Error ", e.getMessage());
}
}
}).start();

You can use picasso lib.
Picasso
.with(context)
.load("http://wallpaperwarrior.com/wp-content/uploads/2016/09/Wallpaper-2.jpeg")
.resize(600, 200)
.centerInside()
.into(imageViewResizeCenterInside);
You can give circle shape to image using Transformation api of picasso.
refer this Picasso

You can try implement with this zoom effect. It is being use by many application. With the example you can create your own background like full screen black background but you need to implement it yourself which is pretty simple but kinda lot of work to do.
Beside why not try to use Glide or Picasso to download and display the image? It help you save a lot work such as caching, download in asyncs,resize etc.
When you work with image especially with recycleview or listview there is some problem you need to always remember. Every time you scroll the listView/RecycleView it actually re-download the image so you have to really check wether it already exist in your sdcard to avoid this problem beside there is better to cache is memory although you already save it on sd card but still you can avoid memory crash by cache it in memory. Those hard work done by using either one of the library I just show you.

Related

Display an image without saving it

My app can download an image from a raspberry. it works fine. This is the code
public void downloadFile() {
FTPClient ftpClient = new FTPClient();
try {
ftpClient.connect("******");
ftpClient.login("****","*****");
ftpClient.enterLocalPassiveMode();
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
String remoteFile1;
File downloadFile1 = new File(filePath);
OutputStream outputStream1 = new BufferedOutputStream(new FileOutputStream(downloadFile1));
boolean success = ftpClient.retrieveFile(remoteFile1, outputStream1);
outputStream1.close();
if (success) {
System.out.println("File #1 has been downloaded successfully.");
} else {
System.out.println("Error in downloading file !");
}
boolean logout = ftpClient.logout();
if (logout) {
System.out.println("Connection close...");
}
} catch (IOException ex) {
System.out.println("Error: " + ex.getMessage());
ex.printStackTrace();
} finally {
try {
ftpClient.disconnect();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
And then I can display it so the user of my app can see it. For the image loading, Im using this code and it works too.
private void loadImage(String imagePath) {
Uri imageUri;
String fullImagePath;
Drawable image;
ImageView imageDisplay;
imageUri = Uri.parse(imagePath);
fullImagePath = imageUri.getPath();
image = Drawable.createFromPath(fullImagePath);
imageDisplay=(ImageView) findViewById(R.id.imageDisplay);
imageDisplay.setImageDrawable(image);
}
Now I want to display the image without downloading it in my gallery. But I can't figure out how to do this.
Can someone help me please.
You cannot show an image without download it. Actually when you see something "remotely", you are downloading it.
If you mean that the image is too large and you don't want to download, but want a mechanism for the user can view it. One possible solution is make a thumbnail (reduced image) in server side and show that "preview" to the user. Then if the user want to download it to the gallery you could get the original image.
If you want to display an image without downloading it, it has to be uploaded in a image hosting site or alike so you will just use the link instead of the whole FTP Client.
Basically, you are using a code that is intended for saving an image. And the one you are using for loading the images fetches data from the Drawable. So you are in the wrong path.

Download images and save it

I'm working on a school android project.
I need to have a download button which downloads a picture(when we have class)
And after display it in another activity(even in offline mode, and after quiting)
I've tried picasso, but I can't get it to save and use it in offline mode.
For you to support offline mode, You need to Save the image on your disk because when your cache is cleared, The image is cleared as well.
You can easily use Glide to Solve this, also storing on device and retrieving
You can Learn more about Glide here http://inthecheesefactory.com/blog/get-to-know-glide-recommended-by-google/en
/** Download the image using Glide **/
Bitmap theBitmap = null;
theBitmap = Glide.
with(YourActivity.this).
load("Url of your image").
asBitmap().
into(-1, -1).
get();
saveToInternalStorage(theBitmap, getApplicationContext(), "your preferred image name");
/** Save it on your device **/
public String saveToInternalStorage(Bitmap bitmapImage, Context context, String name){
ContextWrapper cw = new ContextWrapper(context);
// path to /data/data/yourapp/app_data/imageDir
String name_="foldername"; //Folder name in device android/data/
File directory = cw.getDir(name_, Context.MODE_PRIVATE);
// Create imageDir
File mypath=new File(directory,name);
FileOutputStream fos = null;
try {
fos = new FileOutputStream(mypath);
// Use the compress method on the BitMap object to write image to the OutputStream
bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
Log.e("absolutepath ", directory.getAbsolutePath());
return directory.getAbsolutePath();
}
/** Method to retrieve image from your device **/
public Bitmap loadImageFromStorage(String path, String name)
{
Bitmap b;
String name_="foldername";
try {
File f=new File(path, name_);
b = BitmapFactory.decodeStream(new FileInputStream(f));
return b;
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
return null;
}
/** Retrieve your image from device and set to imageview **/
//Provide your image path and name of the image your previously used.
Bitmap b= loadImageFromStorage(String path, String name)
ImageView img=(ImageView)findViewById(R.id.your_image_id);
img.setImageBitmap(b);
Thanks to #Droidman :
How to download and save an image in Android
Of course you can perform downloading and managing images by yourself,
but if your project is quite complex already, there are a lot of
libraries around and you do not need to reinvent the wheel. I won't
post code this time since there are a lot of examples, but I'm going
to tell you about 2 most useful libraries (IMO) related to image
downloading.
1) Android Volley. A powerful networking library created by Google and
covered by official documentation. POST'ing or GET'ing data, images,
JSON - volley will manage it for you. Using volley just for image
downloading is a bit of an overkill in my opinion.
2) Picasso
Image downloading and caching, perfect for
ListView/GridView/RecyclerView. Apache 2.0 license.
3) Fresco
Quite a new image loading library created by Facebook. Progressive
JPEG streaming, gifs and more. Apache 2.0
You could use Android Library called Universal Image Loader:
https://github.com/nostra13/Android-Universal-Image-Loader

Grab video thumbnail and show it in a Gridview in android

I am developing a module for which i want to show all the user's videos from sd card into a Gridview. I have grabbed video file paths in usual way (Checking if file or directory and save if its a file) in a arraylist and grabbed its bitmap thumbnail with following code:
Bitmap bmThumbnail = ThumbnailUtils.createVideoThumbnail(VideoValues.get(position).getAbsolutePath(),
Thumbnails.MINI_KIND);
Obviously this code runs in a background thread. But the only problem is that the gribview still freezes a lot while scrolling. According to me the main problem is extracting the bitmap from video, which takes a lot of time. Can anyone suggest me a different way to get bitmap from video and how it in a grid ? I have seen the smooth behavior in other apps like Facebook, etc. But I cannot figure out as to how that can be done.
please use below method for retrive video thumbnail from video
#SuppressLint("NewApi")
public static Bitmap retriveVideoFrameFromVideo(String videoPath)
throws Throwable
{
Bitmap bitmap = null;
MediaMetadataRetriever mediaMetadataRetriever = null;
try
{
mediaMetadataRetriever = new MediaMetadataRetriever();
mediaMetadataRetriever.setDataSource(videoPath);
bitmap = mediaMetadataRetriever.getFrameAtTime();
}
catch (Exception e)
{
throw new Throwable(
"Exception in retriveVideoFrameFromVideo(String videoPath)"
+ e.getMessage());
}
finally
{
if (mediaMetadataRetriever != null)
{
mediaMetadataRetriever.release();
}
}
return bitmap;
}

Android: Bitmap.compress poor quality with PNG format

My application captures video footage and saves it as .mp4 file. I would like to extract one frame from this video and also save it to file. Since I haven't found nothing better, I've decided to use MediaMetadataRetriever.getFrameAtTime() for that. It happens inside the class that inherits from AsyncTask. Here is how my code looks like my doInBackground():
Bitmap bitmap1 = null;
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
try {
retriever.setDataSource(src);
bitmap1 = retriever.getFrameAtTime(timeUs, MediaMetadataRetriever.OPTION_CLOSEST_SYNC);
if (Utils.saveBitmap(bitmap1, dst)) {
Log.d(TAG, "doInBackground Image export OK");
} else {
Log.d(TAG, "doInBackground Image export FAILED");
}
} catch (RuntimeException ex) {
Log.d(TAG, "doInBackground Image export FAILED");
} finally {
retriever.release();
if (bitmap1 != null) {
bitmap1.recycle();
}
}
And the saveBitmap() method:
File file = new File(filepath);
boolean result;
try {
result = file.createNewFile();
if (!result) {
return false;
}
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, ostream);
ostream.close();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
Now, the problem is that the quality of the exported image is noticeably worse then the video quality. I don't think that this should happen with PNG output format. You can see the difference below:
The first image was extracted from the video using ffmpeg on my desktop. The second one was extracted using the code above on Samsung Galaxy S6. The result looks pretty much the same on every Android device I was using.
Can someone tell how can I improve the quality of the exported picture?
I found other solution for the issue. You can use bigflake's example to build mechanism for extracting video frame. The one thing you will have to add is seeking mechanism. This works well, keeps the exact quality and does not require any third-party libraries. Only downside I've noticed so far is that it will result in longer execution time than the original idea.

The most efficient way to show the local image in android

I am currently work on a magazine like apps. Since there is an option to zoom in(150%, 200%, 250% of original source) , I would prefer not to scale down the image. However , the app will force restart when I try to decode the image because of the out of memory. Are there any suggestion to fix that?
The image are local (SD card) , can be retrieve in any approach, but eventually need to be a bitmap as I use something like cavans.drawbitmap to display it. I tried, input stream-> bytes , input stream->bitmap etc... but are there any most efficient way or at least
I can sure the app does not force restart / close? Thanks
try {
InputStream is = (InputStream) new URL(url).getContent();
try {
return BitmapFactory.decodeStream(is);
} finally {
is.close();
}
} catch (Exception e) {
return BitmapFactory.decodeResource(context.getResources(), defaultDrawable);
}
You should consider using nostra's image loader, it deals with memory quite efficiently, you can specify lots of config stuffs, im using it and its working pretty well for large images aswell
This is what smartImageView(by loopj - you can find him on http://loopj.com/) uses to retrieve files from the drive/sd.
private Bitmap getBitmapFromDisk(String imgID) {
Bitmap bitmap = null;
if(diskCacheEnabled){
String filePath = getFilePath(imgID);
File file = new File(filePath);
if(file.exists()) {
bitmap = BitmapFactory.decodeFile(filePath);
}
}
return bitmap;
}

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