Whatsapp like Image Compression in Android with demo

Fri Jun 28 2013

Paul Shan

The images captured by the recent cameras often exceed 2 MB. Using such images frequently results in OutOfMemoryError. Also, due to landscape/portrait orientation, the images often are displayed as rotated. To deal with these issues we need to compress the image and give proper rotation before loading it to memory. The following method compresses image (similar to whatsapp), while maintaining its aspect ratio and also preventing significant loss to its quality. A demo project implementing this compression can be downloaded from here. [code language="java"] public String compressImage(String imageUri) { String filePath = getRealPathFromURI(imageUri); Bitmap scaledBitmap = null; BitmapFactory.Options options = new BitmapFactory.Options(); // by setting this field as true, the actual bitmap pixels are not loaded in the memory. Just the bounds are loaded. If // you try the use the bitmap here, you will get null. options.inJustDecodeBounds = true; Bitmap bmp = BitmapFactory.decodeFile(filePath, options); int actualHeight = options.outHeight; int actualWidth = options.outWidth; // max Height and width values of the compressed image is taken as 816x612 float maxHeight = 816.0f; float maxWidth = 612.0f; float imgRatio = actualWidth / actualHeight; float maxRatio = maxWidth / maxHeight; // width and height values are set maintaining the aspect ratio of the image if (actualHeight > maxHeight || actualWidth > maxWidth) { if (imgRatio < maxRatio) { imgRatio = maxHeight / actualHeight; actualWidth = (int) (imgRatio * actualWidth); actualHeight = (int) maxHeight; } else if (imgRatio > maxRatio) { imgRatio = maxWidth / actualWidth; actualHeight = (int) (imgRatio * actualHeight); actualWidth = (int) maxWidth; } else { actualHeight = (int) maxHeight; actualWidth = (int) maxWidth; } } // setting inSampleSize value allows to load a scaled down version of the original image options.inSampleSize = calculateInSampleSize(options, actualWidth, actualHeight); // inJustDecodeBounds set to false to load the actual bitmap options.inJustDecodeBounds = false; // this options allow android to claim the bitmap memory if it runs low on memory options.inPurgeable = true; options.inInputShareable = true; options.inTempStorage = new byte[16 * 1024]; try { // load the bitmap from its path bmp = BitmapFactory.decodeFile(filePath, options); } catch (OutOfMemoryError exception) { exception.printStackTrace(); } try { scaledBitmap = Bitmap.createBitmap(actualWidth, actualHeight,Bitmap.Config.ARGB_8888); } catch (OutOfMemoryError exception) { exception.printStackTrace(); } float ratioX = actualWidth / (float) options.outWidth; float ratioY = actualHeight / (float) options.outHeight; float middleX = actualWidth / 2.0f; float middleY = actualHeight / 2.0f; Matrix scaleMatrix = new Matrix(); scaleMatrix.setScale(ratioX, ratioY, middleX, middleY); Canvas canvas = new Canvas(scaledBitmap); canvas.setMatrix(scaleMatrix); canvas.drawBitmap(bmp, middleX - bmp.getWidth() / 2, middleY - bmp.getHeight() / 2, new Paint(Paint.FILTER_BITMAP_FLAG)); // check the rotation of the image and display it properly ExifInterface exif; try { exif = new ExifInterface(filePath); int orientation = exif.getAttributeInt( ExifInterface.TAG_ORIENTATION, 0); Log.d("EXIF", "Exif: " + orientation); Matrix matrix = new Matrix(); if (orientation == 6) { matrix.postRotate(90); Log.d("EXIF", "Exif: " + orientation); } else if (orientation == 3) { matrix.postRotate(180); Log.d("EXIF", "Exif: " + orientation); } else if (orientation == 8) { matrix.postRotate(270); Log.d("EXIF", "Exif: " + orientation); } scaledBitmap = Bitmap.createBitmap(scaledBitmap, 0, 0, scaledBitmap.getWidth(), scaledBitmap.getHeight(), matrix, true); } catch (IOException e) { e.printStackTrace(); } FileOutputStream out = null; String filename = getFilename(); try { out = new FileOutputStream(filename); // write the compressed bitmap at the destination specified by filename. scaledBitmap.compress(Bitmap.CompressFormat.JPEG, 80, out); } catch (FileNotFoundException e) { e.printStackTrace(); } return filename; } [/code] The method getFilename():: It creates a folder in the SDCard used to store the images. [code language="java"] public String getFilename() { File file = new File(Environment.getExternalStorageDirectory().getPath(), "MyFolder/Images"); if (!file.exists()) { file.mkdirs(); } String uriSting = (file.getAbsolutePath() + "/" + System.currentTimeMillis() + ".jpg"); return uriSting; } [/code] The method getRealPathFromURI(imageUri):: Gives the actual filepath of the image from its contentUri:: [code language="java"] private String getRealPathFromURI(String contentURI) { Uri contentUri = Uri.parse(contentURI); Cursor cursor = getContentResolver().query(contentUri, null, null, null, null); if (cursor == null) { return contentUri.getPath(); } else { cursor.moveToFirst(); int index = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); return cursor.getString(index); } } [/code] The method calculateInSampleSize:: calculates a proper value for inSampleSize based on the actual and required dimensions: [code language="java"] public int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) { final int height = options.outHeight; final int width = options.outWidth; int inSampleSize = 1; if (height > reqHeight || width > reqWidth) { final int heightRatio = Math.round((float) height/ (float) reqHeight); final int widthRatio = Math.round((float) width / (float) reqWidth); inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio; } final float totalPixels = width * height; final float totalReqPixelsCap = reqWidth * reqHeight * 2; while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) { inSampleSize++; } return inSampleSize; } [/code]


Today everyone knows the importance of a lightning-fast website and how the speed impacts the conversion rate of a business. Today, everyone wants the site to be a PWA so that the mobile users can have an app-like experience with the website because, for the majority of the merchants, the customers come through mobile devices.
Tue Apr 20 2021
Here we are going to see how you can manage backup and restore of Postgres database with docker.
Thu Sep 03 2020
Image sliders or carousels always have increased the UI attraction of websites and they are pretty useful for reflecting the major roles/products too. In case, I am having a website that sells tee-shirts,
Mon Apr 30 2018

About VoidCanvas

This blog was created out of hobby and talks mostly about technology, web development, JavaScript, NodeJS and related topics. Thank you for reading my blog.

Copyright 2022 - www.voidcanvas.com

Popular Articles

Authentication using Google's oAuth api with node.js

Thu Mar 10 2016

OAuth authentications are pretty popular now a days and another thing which is popular is JavaScript. This article shows how to plugin google’s oAuth api for authentication in your own node application.

CSS3 Loader Snippet Collection: (Part 2 - Squares)

Sat Mar 01 2014

This is a continuation of my CSS3 loader snippet collection series. I've provided spinning css3 animation loader in the part 1 of this series and here in part 2, I'm providing various square type loading