/opencv-mobile

The minimal opencv for android and ios

Primary LanguageCMakeApache License 2.0Apache-2.0

opencv-mobile

License release download

✔️ This project provides the minimal build of opencv library for the android and ios platforms.

✔️ We provide prebuild binary packages for opencv 2.4.13.7, 3.4.13 and 4.5.1.

✔️ We also provide prebuild binary package for ios with bitcode enabled, that the official package lacks.

✔️ All the binaries are compiled from source on github action, no virus, no backdoor, no secret code.

opencv 4.5.1 android package size
The official opencv 229MB
opencv-mobile 16.7MB
opencv 4.5.1 ios package size
The official opencv 173MB
opencv-mobile 14.4MB
opencv 4.5.1 ios with bitcode package size
The official opencv missing :(
opencv-mobile 50.2MB

Download

android

(armeabi-v7a arm64-v8a x86 x86_64) build with ndk r21d and android api 24

ios

(armv7 arm64 arm64e i386 x86_64) build with Xcode 12.2

ios with bitcode

(armv7 arm64 arm64e i386 x86_64) build with Xcode 12.2

Usage android

  1. Extract archive to <project dir>/app/src/main/jni/
  2. Modify <project dir>/app/src/main/jni/CMakeListst.txt to find and link opencv
set(OpenCV_DIR ${CMAKE_SOURCE_DIR}/opencv-mobile-4.5.1-android/sdk/native/jni)
find_package(OpenCV REQUIRED)

target_link_libraries(your_jni_target ${OpenCV_LIBS})

Usage ios

  1. Extract archive, and drag opencv2.framework into your project
  2. In Build Phases -> Link Binary with Libraries, add libz.tbd

Some notes

  • The minimal opencv build contains most basic opencv operators and common image processing functions, with some handy additions like keypoint feature extraction and matching, image inpainting and opticalflow estimation.

  • Many computer vision algorithms that reside in dedicated modules are discarded, such as face detection etc. You could try deep-learning based algorithms with nerual network inference library optimized for mobile.

  • cuda and opencl are disabled because there is no cuda on mobile, no opencl on ios, and opencl on android is slow. opencv on gpu is not suitable for real productions. Write metal on ios and opengles/vulkan on android if you need good gpu acceleration.

  • C++ RTTI and exceptions are disabled for minimal build. Be careful when you write cv::Mat roi = image(roirect); :P

opencv modules included

module comment
opencv_core Mat, matrix operations, etc
opencv_imgproc resize, cvtColor, warpAffine, etc
opencv_features2d keypoint feature and matcher, etc (not included in opencv 2.x package)
opencv_photo inpaint, etc
opencv_video opticalflow, etc

opencv modules discarded

module comment
opencv_androidcamera use android Camera api instead
opencv_calib3d camera calibration, rare uses on mobile
opencv_contrib experimental functions, build part of the source externally if you need
opencv_dnn very slow on mobile, try ncnn for nerual network inference on mobile
opencv_dynamicuda no cuda on mobile
opencv_flann feature matching, rare uses on mobile, build the source externally if you need
opencv_gapi graph based image processing, little gain on mobile
opencv_gpu no cuda/opencl on mobile
opencv_highgui use android Bitmap or ios UIImage api instead
opencv_imgcodecs use android Bitmap or ios UIImage api instead
opencv_java wrap your c++ code with jni
opencv_js write native code on mobile
opencv_lagacy various good-old cv routines, build part of the source externally if you need
opencv_ml train your ML algorithm on powerful pc or server
opencv_nonfree the SIFT and SURF, use ORB which is faster and better
opencv_objdetect HOG, cascade detector, use deep learning detector which is faster and better
opencv_ocl no opencl on mobile
opencv_python no python on mobile
opencv_shape shape matching, rare uses on mobile, build the source externally if you need
opencv_stitching image stitching, rare uses on mobile, build the source externally if you need
opencv_superres do video super-resolution on powerful pc or server
opencv_ts test modules, useless in production anyway
opencv_videoio use android MediaCodec or ios AVFoundation api instead
opencv_videostab do video stablization on powerful pc or server
opencv_viz vtk is not available on mobile, write your own data visualization routines