Table Of Contents

Previous topic

FrameStreamer Class

Next topic

ImageTarget Class

Image Class

Description

Image stores an image data and represents an image in memory.

Image raw data can be accessed as byte array. The width/height/stride information are also accessible.

(since 2.1.0) To access image data in Java API, get buffer from Image and copy to a Java byte array.

You can always access image data from the first version of EasyAR SDK, and it is even easier in EasyAR SDK 2.1.

You can do this in iOS

#import <easyar/buffer.oc.h>
#import <easyar/image.oc.h>

easyar_Frame * frame = [streamer peek];
for (easyar_Image * i in [frame images]) {
    easyar_Buffer * b = [i buffer];
    char * bytes = calloc([b size], 1);
    memcpy(bytes, [b data], [b size]);
    //TODO: use bytes here
    free(bytes);
}

Or in Android (since 2.1.0)

import cn.easyar.Buffer;
import cn.easyar.Image;

Frame frame = streamer.peek();
for (Image i : frame.images()) {
    Buffer b = i.buffer();
    byte[] bytes = new byte[b.size()];
    b.copyTo(bytes, 0);
    //TODO: use bytes here
}

Before 2.1.0, you can only pass data to JNI then pass data back to Java by yourself, or you can use that data directly in C/C++ layer.

buffer

(since 2.1.0) Return buffer inside image. It can be used to access internal data of image.

C: void easyar_Image_buffer(const easyar_Image* This, easyar_Buffer** Return)
C++11: std::shared_ptr<Buffer> buffer()
Traditional C++: void buffer(Buffer** Return)
Java: public native Buffer buffer()
Objective-C: - (easyar_Buffer *)buffer
Swift (since EasyAR SDK 2.1.0): public func buffer() -> Buffer

width

Returns image width.

C: int easyar_Image_width(const easyar_Image* This)
C++11: int width()
Traditional C++: int width()
Java: public native int width()
Objective-C: - (int)width
Swift (since EasyAR SDK 2.1.0): public func width() -> Int32

height

Returns image height.

C: int easyar_Image_height(const easyar_Image* This)
C++11: int height()
Traditional C++: int height()
Java: public native int height()
Objective-C: - (int)height
Swift (since EasyAR SDK 2.1.0): public func height() -> Int32

stride

Returns image stride.

C: int easyar_Image_stride(const easyar_Image* This)
C++11: int stride()
Traditional C++: int stride()
Java: public native int stride()
Objective-C: - (int)stride
Swift (since EasyAR SDK 2.1.0): public func stride() -> Int32

format

Returns image format. Generally, you will get a YUV image from camera on mobile devices and BGR image from camera on desktop devices.

C: easyar_PixelFormat easyar_Image_format(const easyar_Image* This)
C++11: PixelFormat format()
Traditional C++: PixelFormat format()
Java: public native /* PixelFormat */ int format()
Objective-C: - (easyar_PixelFormat)format
Swift (since EasyAR SDK 2.1.0): public func format() -> PixelFormat

data

Returns image raw data as a byte array.

C: void* easyar_Image_data(const easyar_Image* This)
C++11: void * data()
Traditional C++: void* data()
Java: public native long data()
Objective-C: - (void *)data
Swift (since EasyAR SDK 2.1.0): public func data() -> OpaquePointer