Develop Reference

How to resize a base64 image to occupy less?

I have an Bitmap image hat i convert to base64, but I want that the image to occupy less because I want to upload that image to a database and it needs to be less than a mb.
Convert from Bitmap to base 64:
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
imagen.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
byte[] byteArray = byteArrayOutputStream.toByteArray();
final String imagenPlanta = Base64.encodeToString(byteArray, Base64.DEFAULT);
Any help would be appreciated.

To make it smaller you have to get rid of information. Do something like JPEG, it will focus on removing information that is less relevant, many times a JPEG image looks just fine but is like 10 times smaller.

Image size is too small Azure Face API Android

I am trying to use the Azure Face API on android. I am capturing an image from the device camera and then converting it to an InputStream to be sent to the detect method. I keep getting the error "com.microsoft.projectoxford.face.rest.ClientException: Image size is too small"
I checked the documentation and the image size is 1.4Mb which is within the 1Kb-4Mb range. I don't understand why it isn't working.
Bitmap bitmap = cameraKitImage.getBitmap();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, bos);
bitmapdata = bos.toByteArray();
new FaceTask().execute(new ByteArrayInputStream(bitmapdata));
Face[] faces = faceServiceClient.detect(inputStreams[0], true, false, null);

Somehow your file is being compressed more than 1Kb or if it is small in actual size already. Try to save it somewhere in the drawable or assets folder and open it in the input stream.

Decreasing File Size of Image From ImageView

I use the following code to obtain a bitmap from an ImageView. This image is not saved anywhere else on my device. I want to upload this image into an online mysqli database. However, to do so I need to decrease the size of the file first. I found a lot of links about this, however they all require the file to be saved on the device and then use FileOutputStream. I am looking for a way to reduce the file size so that it can be comfortably transferred using the Volley API ( i am currently receiving either run out of memory exceptions or broken pipe errors). Hence I am looking for a way to modify this code to be able to significantly decrease the file size, whilst still maintaining a quality which can be comfortably shown on a mobile device. The original image is taken straight from the camera hence the size is quite large. Here is my code:
ImageView pic_holder = (ImageView) findViewById(R.id.picturedisplay);
Bitmap bitmap = ((BitmapDrawable)pic_holder.getDrawable()).getBitmap();
ByteArrayOutputStream stream=new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 90, stream);
byte[] image=stream.toByteArray();
String img_str = Base64.encodeToString(image, 0);
I would like to decrease the size of the img_str which is passed to my Volley method.

Convert YUV imageformat to PNG

I was struggeling to get YuvImage to a png imageformat on an Android 5.0.1 device where the png showed up as green images. On a Android 5.1.1 this did not happend, and the images was showing just fine.
After some time I found out that there is a bug in Android 5.0.1 which makes the images that are converted appear green. This was fixed in Android 5.1.1
However, does anyone know about a solution in order to make this work on devices that has not got this fix?

I don't think there is a way to workaround the bug because in my experience the images are already green when generated by the system, and it is not a problem of the conversion to PNG.
I see that you are using the Camera 2 API from your comment response, and since you are using YUV format I believe you are trying to save images from the continuous feed from the camera (as opposed from full resolution picture taking). If that is the case, I'll suggest using the older Camera API if at all possible, as I haven't seen a device that does not work when capturing preview images in YUV format (NV21), which can easily converted to a PNG, although having to go through a JPEG step:
YuvImage yuvImage = new YuvImage(nv21bytearray, ImageFormat.NV21, width, height, null);
ByteArrayOutputStream os = new ByteArrayOutputStream();
yuvImage.compressToJpeg(new Rect(0, 0, width, height), 100, os);
byte[] jpegByteArray = os.toByteArray();
Bitmap bitmap = BitmapFactory.decodeByteArray(jpegByteArray, 0, jpegByteArray.length);
FileOutputStream fos = new FileOutputStream(Environment.getExternalStorageDirectory() + "/imagename.png");
bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
fos.close();
with nv21bytearray being the NV21 byte array returned by the old camera API onPreviewFrame(...) method.

Why the color of the image changed when it compressed by Bitmap.CompressFormat.JPEG

I am trying to compress the photo took by the camera in Android. But the color of the image changed when it compressed by Bitmap.CompressFormat.JPEG. How can I solve this problem? Thanks
I have put some sample images which generated from my code. You can see the color of the paper on the top of the images is different.
Here is the code snippet:
Bitmap bitmap = BitmapFactory.decodeFile(Common.FOLDER_PATH + "pic.jpg");
FileOutputStream stream2 = new FileOutputStream(Common.FOLDER_PATH + "pic100.jpg");
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream2);
FileOutputStream stream3 = new FileOutputStream(Common.FOLDER_PATH + "pic100.png");
bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream3);
This is original image:
This is JPEG:
This is PNG:

JPEG is a lossy compression format and there may be loss of image information during the compression. The sacrifice of original image information is made for a better compression ratio (resulting in smaller file).
However, if this is not acceptable for you, you should use one of the lossless compression methods which includes the PNG.