CODEWITHSUNDEEP
androidbitmapout-of-memoryface-detection
android developer
android developer

Reputation: 116060

How to overcome the face detection API restrictions?

background

i'm developing an app that at some point it has a huge bitmap and it needs to use face detection on it, so i use the FaceDetector API

the problem

the face detection API has restrictions about its input bitmap:

  1. the bitmap config must be Config.RGB_565 (written here)
  2. the bitmap width must be even (written here)

what i've done

since i need to have the original bitmap later, i've stored it into a file.

right after that i recycle the original bitmap, and load a temporary one from the file, having the right config, but sadly, it won't always work since i need to use an even width, and the original bitmap doesn't always have an even width.

i've tried telling the face detection API to use "width-1" as the width, but it didn't work. it said "java.lang.IllegalArgumentException: bitmap size doesn't match initialization". i don't even understand why it needs such a weird width restriction and why it needs the parameters of the width and height if it already has the bitmap...

the question

what should i do?

is it possible to make it work with odd-width bitmaps , and maybe ignore a whole column of pixels?

the reason i ask this is because the bitmap is quite large, and if i clone it to a new one that has a similar size (with an even width), i can easily get OOM on some devices.

i know i can scale using JNI (similar to a post i've written some time ago,here) , but i hope i can find a better, less hardcore-way to achieve the same thing.

if there is no other way, maybe android has a JNI functions that could help ?

Upvotes: 1

Views: 919

Answers (1)

Raghav
Raghav

Reputation: 1

This can be used for converting the bitmap in the required format (The bitmap must be in 565 format).

Bitmap mFaceBitmap = bitmapImage.copy(Bitmap.Config.RGB_565, true); bitmapImage.recycle(); // If you want to free memory ASAP

And to alter the width, you can try something like

mFaceBitmapWidth = mFaceBitmap.getWidth(); mFaceBitmap.setWidth(mFaceBitmapWidth - 1);

Upvotes: 0

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