bitmapfactory

问题 I want to decode an image from the SD card with BitmapFactory.decodeFile(path, options). I also want images that are larger than 2048x2048 pixels to be scaled down to at most 2048x2048 (maintaining the proportions). I could do this manually after getting the bitmap, but that would require allocating a large amount of bytes in addition to the ones already allocated. How should i set up my BitmapFactory.Options object to get that effect? Thanks 回答1: Use BitmapFactory.Options.inSampleSize when

问题 I have to print some data on thermal bluetooth printer, I'm doing with this: String message="abcdef any message 12345"; byte[] send; send = message.getBytes(); mService.write(send); It works well for text, but not for images. I think I need to get the byte[] of the image data. I tried getting the data of the image this way: Bitmap bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.qrcode); ByteArrayOutputStream stream=new ByteArrayOutputStream(); bitmap.compress(Bitmap

问题 i want to write an app that displays images from a Cherokee webserver. I do download the images with the following code: @Override protected Bitmap doInBackground(URL... params) { URL urlToDownload = params[0]; String downloadFileName = urlToDownload.getFile(); downloadFile = new File(applicationContext.getCacheDir(), downloadFileName); new File(downloadFile.getParent()).mkdirs(); // create all necessary folders // download the file if it is not already cached if (!downloadFile.exists()) {

问题 I'm using following code from here. I want to compress image. BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; Bitmap bmp = BitmapFactory.decodeFile(filePath, options); int actualHeight = options.outHeight; int actualWidth = options.outWidth; After choose image from Camera, Gallery and Photos, i'm getting different type of paths in different devices based on OS type and device model. like: 1) /storage/emulated/0/Android/data/... 2) /raw//storage

问题 I'm trying to create a file that is eventually going to hold a picture (EXTRA_OUTPUT) like this: File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory( Environment.DIRECTORY_PICTURES), "scouthouse"); if(!mediaStorageDir.exists()) { mediaStorageDir.mkdirs(); } SimpleDateFormat s = new SimpleDateFormat("ddMMyyyyhhmmss"); String format = s.format(new Date()); File file = new File(mediaStorageDir.getPath() + File.separator + format + ".jpg"); try { file.createNewFile(); }

问题 I'm trying to better understand how Android handle images in order to use memory more efficiently. I have an image stored in the Bitmap and I'm using ImageView.setImageBitmap() to display it. Now the question is - will it use the Bitmap I've passed it in the future, or it's making a copy of it and the Bitmap I've created isn't used anymore after the call to setImageBitmap ? Asuming it's gonna keep reference to the Bitmap I've passed, how is it gonna behave when Bitmap was created via

问题 I am using following method to retrieve a bitmap from the url and pass it on to the imageview , but the imageview is not being updated. public static Bitmap LoadImageFromWebOperations(String url) { Bitmap bitmap; try { InputStream is = new URL(url).openStream(); bitmap = BitmapFactory.decodeStream(is); return bitmap; } catch (Exception e) { return null; } call - mov1_poster.setImageBitmap(VPmovies.LoadImageFromWebOperations(mov_details[0][7])); //doesn't work Toast.makeText(this,"url is \n"

问题 I want to add an image uploader to my app, I can choose an image from the image folder, but when I chose an image, the image path is only displayed as "null", and when I click upload, I get this Error: BitmapFactory﹕ Unable to decode stream: java.lang.NullPointerException: This is my code: package com.test.mysqltest; import java.io.DataOutputStream; import java.io.File; import java.io.FileInputStream; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net

问题 SOLUTION Thanks to @ChandraSekhar's suggestions the issue was that I was passing in an Immutable Bitmap to the canvas constructor. The solution is to create a copy of it when using BitmapFactory.decodeFile(); Bitmap bmp = BitmapFactory.decodeFile(imageURL).copy(Bitmap.Config.ARGB_8888, true); So I have a bitmap that I am using bitmapFactory.decodeFile() for and this works. I am able to create the bitmap, then I need to create a canvas and this is where things get weird. Here's the flow of

问题 I'm trying to set a .PNG file as background on Canvas in my app. I've made an image 480 x 800 and used this method: canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.image_1), 0, 0, null); I've started an emulator (WVGA800) but my image looks greater than screen of the device. How do I resize this image or what kind of methods should I use to make this image well-matched. Secondly, is there any way to make backgrounds like this universal for devices with different