Leptonica OpenCV Java 将 Mat 转换为 Pix，反之亦然答案

【问题标题】：Leptonica OpenCV Java convert Mat to Pix and vise versaLeptonica OpenCV Java 将 Mat 转换为 Pix，反之亦然
【发布时间】：2018-02-19 14:41:22
【问题描述】：

我使用以下 lept4j 和 OpenCV Maven 依赖项：

<!-- Leptonica -->
<dependency>
    <groupId>net.sourceforge.lept4j</groupId>
    <artifactId>lept4j</artifactId>
    <version>1.9.0</version>
</dependency>

<!-- OpenCV -->
<dependency>
    <groupId>org.openpnp</groupId>
    <artifactId>opencv</artifactId>
    <version>3.2.0-1</version>
</dependency>

我想同时使用 OpenCV 和 Leptonica 函数。为此，我需要能够将 Mat 转换为 Pix 并将 Pix 转换为 Mat。

这是我现在拥有的：

public static Pix matToGrayscalePix(Mat mat) {

    if (mat == null) {
        throw new IllegalArgumentException("Recycled matrix");
    }

    final byte[] bytes = new byte[(int) mat.total()];
    mat.get(0, 0, bytes);

    ByteBuffer buff = ByteBuffer.wrap(bytes);
    return Leptonica1.pixReadMem(buff, new NativeSize(buff.capacity()));
}

public static Mat pixToGrayscaleMat(Pix pix) {

    if (pix == null) {
        throw new IllegalArgumentException("Recycled matrix");
    }

    PointerByReference pdata = new PointerByReference();
    NativeSizeByReference psize = new NativeSizeByReference();
    int format = net.sourceforge.lept4j.ILeptonica.IFF_TIFF;
    Leptonica1.pixWriteMem(pdata, psize, pix, format);
    byte[] b = pdata.getValue().getByteArray(0, psize.getValue().intValue());

    return new MatOfByte(b).reshape(0, pix.h);
}

但是这些功能现在不起作用。我做错了什么？

【问题讨论】：

标签： opencv leptonica

【解决方案1】：

尝试以下方法：

public static Pix convertMatToPix(Mat mat) {
    MatOfByte bytes = new MatOfByte();
    Imgcodecs.imencode(".tif", mat, bytes);
    ByteBuffer buff = ByteBuffer.wrap(bytes.toArray());
    return Leptonica1.pixReadMem(buff, new NativeSize(buff.capacity()));
}

public static Mat convertPixToMat(Pix pix) {
    PointerByReference pdata = new PointerByReference();
    NativeSizeByReference psize = new NativeSizeByReference();
    Leptonica1.pixWriteMem(pdata, psize, pix, ILeptonica.IFF_TIFF);
    byte[] b = pdata.getValue().getByteArray(0, psize.getValue().intValue());
    Leptonica1.lept_free(pdata.getValue());
    return Imgcodecs.imdecode(new MatOfByte(b), Imgcodecs.CV_LOAD_IMAGE_UNCHANGED);
}

【讨论】：