Membina SDK Kamera Python dan Menggunakannya untuk Pengimbasan Berbilang Kod Bar

Sekarang SDK kamera C ringan telah lengkap untuk Windows, Linux dan macOS, kami boleh menyepadukannya ke dalam bahasa pengaturcaraan peringkat tinggi yang lain. Dalam artikel ini, kami akan meneroka cara membina SDK kamera Python berdasarkan pustaka kamera C dan menggunakannya untuk pengimbasan berbilang kod bar dengan SDK Pembaca Kod Bar Dynamsoft.

Video Demo Pengimbas Berbilang Kod Bar Python

Perancah Projek Sambungan CPython

Sambungan CPython ialah pustaka kongsi (cth., DLL pada Windows, .so pada Linux atau .dylib pada macOS) yang boleh dimuatkan ke dalam penterjemah Python semasa runtime dan digunakan untuk melanjutkan fungsinya. Struktur projek sambungan CPython kamera ringan adalah seperti berikut:

python-lite-camera
│
│── include
│   ├── Camera.h
│   ├── CameraPreview.h
│   ├── stb_image_write.h
│── lib
│   ├── linux
│   │   ├── liblitecam.so
│   ├── macos
│   │   ├── liblitecam.dylib
│   ├── windows
│   │   ├── litecam.dll
│   │   ├── litecam.lib
├── src
│   ├── litecam.cpp
│   ├── pycamera.h
│   ├── pywindow.h
│── litecam
│   ├── __init__.py
│── setup.py
│── MANIFEST.in
│── README.md

Penjelasan:

• termasuk: Fail pengepala pustaka kamera C.
• lib: Pustaka kongsi pustaka kamera C.
• src: Kod sumber SDK kamera Python.
• litecam: Titik masuk sambungan Python.
• setup.py: Skrip binaan.
• MANIFEST.in: Fail manifes untuk memasukkan fail bukan Python.
• README.md: Dokumentasi.

Menulis Build Script setup.py untuk Sambungan Python

Tambah kandungan berikut pada setup.py:

from setuptools.command import build_ext
from setuptools import setup, Extension
import sys
import os
import io
from setuptools.command.install import install
import shutil
from pathlib import Path

lib_dir = ''

sources = [
    "src/litecam.cpp",
]

include_dirs = [os.path.join(os.path.dirname(__file__), "include")]

libraries = ['litecam']

extra_compile_args = []

if sys.platform == "linux" or sys.platform == "linux2":
    lib_dir = 'lib/linux'
    extra_compile_args = ['-std=c++11']
    extra_link_args = ["-Wl,-rpath=$ORIGIN"]
elif sys.platform == "darwin":
    lib_dir = 'lib/macos'
    extra_compile_args = ['-std=c++11']
    extra_link_args = ["-Wl,-rpath,@loader_path"]
elif sys.platform == "win32":
    lib_dir = 'lib/windows'
    extra_link_args = []

else:
    raise RuntimeError("Unsupported platform")


long_description = io.open("README.md", encoding="utf-8").read()

module_litecam = Extension(
    "litecam",
    sources=sources,
    include_dirs=include_dirs,
    library_dirs=[lib_dir],
    libraries=libraries,
    extra_compile_args=extra_compile_args,
    extra_link_args=extra_link_args,
)

def copyfiles(src, dst):
    if os.path.isdir(src):
        filelist = os.listdir(src)
        for file in filelist:
            libpath = os.path.join(src, file)
            shutil.copy2(libpath, dst)
    else:
        shutil.copy2(src, dst)


class CustomBuildExt(build_ext.build_ext):
    def run(self):
        build_ext.build_ext.run(self)
        dst = os.path.join(self.build_lib, "litecam")
        copyfiles(lib_dir, dst)
        filelist = os.listdir(self.build_lib)
        for file in filelist:
            filePath = os.path.join(self.build_lib, file)
            if not os.path.isdir(file):
                copyfiles(filePath, dst)
                os.remove(filePath)


class CustomBuildExtDev(build_ext.build_ext):
    def run(self):
        build_ext.build_ext.run(self)
        dev_folder = os.path.join(Path(__file__).parent, 'litecam')
        copyfiles(lib_dir, dev_folder)
        filelist = os.listdir(self.build_lib)
        for file in filelist:
            filePath = os.path.join(self.build_lib, file)
            if not os.path.isdir(file):
                copyfiles(filePath, dev_folder)


class CustomInstall(install):
    def run(self):
        install.run(self)


setup(name='lite-camera',
      version='2.0.1',
      description='LiteCam is a lightweight, cross-platform library for capturing RGB frames from cameras and displaying them. Designed with simplicity and ease of integration in mind, LiteCam supports Windows, Linux and macOS platforms.',
      long_description=long_description,
      long_description_content_type="text/markdown",
      author='yushulx',
      url='https://github.com/yushulx/python-lite-camera',
      license='MIT',
      packages=['litecam'],
      ext_modules=[module_litecam],
      classifiers=[
           "Development Status :: 5 - Production/Stable",
           "Environment :: Console",
           "Intended Audience :: Developers",
          "Intended Audience :: Education",
          "Intended Audience :: Information Technology",
          "Intended Audience :: Science/Research",
          "License :: OSI Approved :: MIT License",
          "Operating System :: Microsoft :: Windows",
          "Operating System :: MacOS",
          "Operating System :: POSIX :: Linux",
          "Programming Language :: Python",
          "Programming Language :: Python :: 3",
          "Programming Language :: Python :: 3 :: Only",
          "Programming Language :: Python :: 3.6",
          "Programming Language :: Python :: 3.7",
          "Programming Language :: Python :: 3.8",
          "Programming Language :: Python :: 3.9",
          "Programming Language :: Python :: 3.10",
          "Programming Language :: Python :: 3.11",
          "Programming Language :: Python :: 3.12",
          "Programming Language :: C++",
          "Programming Language :: Python :: Implementation :: CPython",
          "Topic :: Scientific/Engineering",
          "Topic :: Software Development",
      ],
      cmdclass={
          'install': CustomInstall,
          'build_ext': CustomBuildExt,
          'develop': CustomBuildExtDev},
      )

Penjelasan:

• lite-camera: Nama pakej Python.
• ext_modules: Senarai sambungan CPython. Ia menentukan fail sumber, termasuk direktori, direktori perpustakaan, pustaka dan bendera kompil/pautan untuk platform yang berbeza.
• membangunkan: Perintah tersuai untuk pembangunan. Ia menyalin perpustakaan kongsi ke folder litecam untuk ujian mudah.
• build_ext: Menyesuaikan proses binaan untuk membungkus perpustakaan kongsi ke dalam pakej roda.

Melaksanakan API SDK Kamera Python dalam C

Fail pycamera.h mentakrifkan kelas Python PyCamera untuk menangkap bingkai daripada kamera, manakala fail pywindow.h mentakrifkan kelas Python PyWindow untuk memaparkan bingkai dalam tetingkap. Fail litecam.cpp berfungsi sebagai titik masuk untuk sambungan Python, di mana beberapa kaedah global ditakrifkan, dan kelas PyCamera dan PyWindow didaftarkan.

pycamera.h

Termasuk

python-lite-camera
│
│── include
│   ├── Camera.h
│   ├── CameraPreview.h
│   ├── stb_image_write.h
│── lib
│   ├── linux
│   │   ├── liblitecam.so
│   ├── macos
│   │   ├── liblitecam.dylib
│   ├── windows
│   │   ├── litecam.dll
│   │   ├── litecam.lib
├── src
│   ├── litecam.cpp
│   ├── pycamera.h
│   ├── pywindow.h
│── litecam
│   ├── __init__.py
│── setup.py
│── MANIFEST.in
│── README.md

• Python.h: Disertakan untuk menggunakan API Python C.
• structmember.h: Menyediakan makro dan pembantu untuk mengurus ahli objek.
• Camera.h: Mentakrifkan kelas Kamera, yang dibungkus oleh sambungan PyCamera.

Definisi Struktur PyCamera

from setuptools.command import build_ext
from setuptools import setup, Extension
import sys
import os
import io
from setuptools.command.install import install
import shutil
from pathlib import Path

lib_dir = ''

sources = [
    "src/litecam.cpp",
]

include_dirs = [os.path.join(os.path.dirname(__file__), "include")]

libraries = ['litecam']

extra_compile_args = []

if sys.platform == "linux" or sys.platform == "linux2":
    lib_dir = 'lib/linux'
    extra_compile_args = ['-std=c++11']
    extra_link_args = ["-Wl,-rpath=$ORIGIN"]
elif sys.platform == "darwin":
    lib_dir = 'lib/macos'
    extra_compile_args = ['-std=c++11']
    extra_link_args = ["-Wl,-rpath,@loader_path"]
elif sys.platform == "win32":
    lib_dir = 'lib/windows'
    extra_link_args = []

else:
    raise RuntimeError("Unsupported platform")


long_description = io.open("README.md", encoding="utf-8").read()

module_litecam = Extension(
    "litecam",
    sources=sources,
    include_dirs=include_dirs,
    library_dirs=[lib_dir],
    libraries=libraries,
    extra_compile_args=extra_compile_args,
    extra_link_args=extra_link_args,
)

def copyfiles(src, dst):
    if os.path.isdir(src):
        filelist = os.listdir(src)
        for file in filelist:
            libpath = os.path.join(src, file)
            shutil.copy2(libpath, dst)
    else:
        shutil.copy2(src, dst)


class CustomBuildExt(build_ext.build_ext):
    def run(self):
        build_ext.build_ext.run(self)
        dst = os.path.join(self.build_lib, "litecam")
        copyfiles(lib_dir, dst)
        filelist = os.listdir(self.build_lib)
        for file in filelist:
            filePath = os.path.join(self.build_lib, file)
            if not os.path.isdir(file):
                copyfiles(filePath, dst)
                os.remove(filePath)


class CustomBuildExtDev(build_ext.build_ext):
    def run(self):
        build_ext.build_ext.run(self)
        dev_folder = os.path.join(Path(__file__).parent, 'litecam')
        copyfiles(lib_dir, dev_folder)
        filelist = os.listdir(self.build_lib)
        for file in filelist:
            filePath = os.path.join(self.build_lib, file)
            if not os.path.isdir(file):
                copyfiles(filePath, dev_folder)


class CustomInstall(install):
    def run(self):
        install.run(self)


setup(name='lite-camera',
      version='2.0.1',
      description='LiteCam is a lightweight, cross-platform library for capturing RGB frames from cameras and displaying them. Designed with simplicity and ease of integration in mind, LiteCam supports Windows, Linux and macOS platforms.',
      long_description=long_description,
      long_description_content_type="text/markdown",
      author='yushulx',
      url='https://github.com/yushulx/python-lite-camera',
      license='MIT',
      packages=['litecam'],
      ext_modules=[module_litecam],
      classifiers=[
           "Development Status :: 5 - Production/Stable",
           "Environment :: Console",
           "Intended Audience :: Developers",
          "Intended Audience :: Education",
          "Intended Audience :: Information Technology",
          "Intended Audience :: Science/Research",
          "License :: OSI Approved :: MIT License",
          "Operating System :: Microsoft :: Windows",
          "Operating System :: MacOS",
          "Operating System :: POSIX :: Linux",
          "Programming Language :: Python",
          "Programming Language :: Python :: 3",
          "Programming Language :: Python :: 3 :: Only",
          "Programming Language :: Python :: 3.6",
          "Programming Language :: Python :: 3.7",
          "Programming Language :: Python :: 3.8",
          "Programming Language :: Python :: 3.9",
          "Programming Language :: Python :: 3.10",
          "Programming Language :: Python :: 3.11",
          "Programming Language :: Python :: 3.12",
          "Programming Language :: C++",
          "Programming Language :: Python :: Implementation :: CPython",
          "Topic :: Scientific/Engineering",
          "Topic :: Software Development",
      ],
      cmdclass={
          'install': CustomInstall,
          'build_ext': CustomBuildExt,
          'develop': CustomBuildExtDev},
      )

Struktur PyCamera mewakili objek Python yang melilit objek C Camera. Pengendali ialah penunjuk kepada contoh kelas Kamera.

Kaedah

• PyCamera_dealloc
  

  #include <Python.h>
  #include <structmember.h>
  #include "Camera.h"
  

  Mengagihkan objek Kamera dan melepaskan memori yang berkaitan.

• PyCamera_new
  

  typedef struct
  {
      PyObject_HEAD Camera *handler;
  } PyCamera;
  

  Mencipta contoh baharu PyCamera. Ia memperuntukkan memori untuk objek Python, mencipta objek Kamera baharu dan menyerahkannya kepada pengendali sendiri.

• terbuka
  

  static int PyCamera_clear(PyCamera *self)
  {
      if (self->handler)
      {
          delete self->handler;
      }
      return 0;
  }
  
  static void PyCamera_dealloc(PyCamera *self)
  {
      PyCamera_clear(self);
      Py_TYPE(self)->tp_free((PyObject *)self);
  }
  
  

  Membuka kamera dengan indeks yang ditentukan.

• listMediaTypes
  

  static PyObject *PyCamera_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
  {
      PyCamera *self;
  
      self = (PyCamera *)type->tp_alloc(type, 0);
      if (self != NULL)
      {
          self->handler = new Camera();
      }
  
      return (PyObject *)self;
  }
  
  

  Mengembalikan senarai jenis media yang disokong. Untuk Windows, ia menukar rentetan aksara lebar kepada objek Unicode Python.

• lepaskan
  

  static PyObject *open(PyObject *obj, PyObject *args)
  {
      PyCamera *self = (PyCamera *)obj;
  
      int index = 0;
      if (!PyArg_ParseTuple(args, "i", &index))
      {
          return NULL;
      }
  
      bool ret = self->handler->Open(index);
      return Py_BuildValue("i", ret);
  }
  

  Melepaskan kamera.

• setResolution
  

  static PyObject *listMediaTypes(PyObject *obj, PyObject *args)
  {
      PyCamera *self = (PyCamera *)obj;
  
      std::vector<MediaTypeInfo> mediaTypes = self->handler->ListSupportedMediaTypes();
  
      PyObject *pyList = PyList_New(0);
  
      for (size_t i = 0; i < mediaTypes.size(); i++)
      {
          MediaTypeInfo &mediaType = mediaTypes[i];
  
  #ifdef _WIN32
          PyObject *subtypeName = PyUnicode_FromWideChar(mediaType.subtypeName, wcslen(mediaType.subtypeName));
          PyObject *pyMediaType = Py_BuildValue("{s:i,s:i,s:O}",
                                                "width", mediaType.width,
                                                "height", mediaType.height,
                                                "subtypeName", subtypeName);
          if (subtypeName != NULL)
          {
              Py_DECREF(subtypeName);
          }
  
  #else
          PyObject *pyMediaType = Py_BuildValue("{s:i,s:i,s:s}",
                                                "width", mediaType.width,
                                                "height", mediaType.height,
                                                "subtypeName", mediaType.subtypeName);
  #endif
  
          PyList_Append(pyList, pyMediaType);
      }
  
      return pyList;
  }
  
  

  Menetapkan resolusi kamera.

• captureFrame
  

  static PyObject *release(PyObject *obj, PyObject *args)
  {
      PyCamera *self = (PyCamera *)obj;
  
      self->handler->Release();
      Py_RETURN_NONE;
  }
  

  Merakam bingkai daripada kamera dan mengembalikan data RGB sebagai tatasusunan bait Python.

• getWidth dan getHeight
  

  static PyObject *setResolution(PyObject *obj, PyObject *args)
  {
      PyCamera *self = (PyCamera *)obj;
      int width = 0, height = 0;
      if (!PyArg_ParseTuple(args, "ii", &width, &height))
      {
          return NULL;
      }
      int ret = self->handler->SetResolution(width, height);
      return Py_BuildValue("i", ret);
  }
  

  Mengembalikan lebar dan ketinggian bingkai yang ditangkap.

contoh_kaedah

static PyObject *captureFrame(PyObject *obj, PyObject *args)
{
    PyCamera *self = (PyCamera *)obj;

    FrameData frame = self->handler->CaptureFrame();
    if (frame.rgbData)
    {
        PyObject *rgbData = PyByteArray_FromStringAndSize((const char *)frame.rgbData, frame.size);
        PyObject *pyFrame = Py_BuildValue("iiiO", frame.width, frame.height, frame.size, rgbData);
        ReleaseFrame(frame);

        return pyFrame;
    }
    else
    {
        Py_RETURN_NONE;
    }
}

Mentakrifkan kaedah yang tersedia pada objek PyCamera Python. Kaedah ini dikaitkan dengan fungsi C sepadan yang ditakrifkan di atas.

PyCameraType

static PyObject *getWidth(PyObject *obj, PyObject *args)
{
    PyCamera *self = (PyCamera *)obj;

    int width = self->handler->frameWidth;
    return Py_BuildValue("i", width);
}

static PyObject *getHeight(PyObject *obj, PyObject *args)
{
    PyCamera *self = (PyCamera *)obj;

    int height = self->handler->frameHeight;
    return Py_BuildValue("i", height);
}

Mentakrifkan jenis PyCamera, termasuk kaedahnya, peruntukan memori, deallocation dan gelagat lain.

pywindow.h

Termasuk

static PyMethodDef instance_methods[] = {
    {"open", open, METH_VARARGS, NULL},
    {"listMediaTypes", listMediaTypes, METH_VARARGS, NULL},
    {"release", release, METH_VARARGS, NULL},
    {"setResolution", setResolution, METH_VARARGS, NULL},
    {"captureFrame", captureFrame, METH_VARARGS, NULL},
    {"getWidth", getWidth, METH_VARARGS, NULL},
    {"getHeight", getHeight, METH_VARARGS, NULL},
    {NULL, NULL, 0, NULL}};

• Python.h: Diperlukan untuk menggunakan Python C API.
• structmember.h: Menyediakan makro untuk mengurus ahli objek.
• CameraPreview.h: Mentakrifkan kelas CameraWindow, yang digunakan untuk memaparkan pratonton kamera dan berinteraksi dengannya.

Definisi Struktur PyWindow

static PyTypeObject PyCameraType = {
    PyVarObject_HEAD_INIT(NULL, 0) "litecam.PyCamera", /* tp_name */
    sizeof(PyCamera),                                  /* tp_basicsize */
    0,                                                 /* tp_itemsize */
    (destructor)PyCamera_dealloc,                      /* tp_dealloc */
    0,                                                 /* tp_print */
    0,                                                 /* tp_getattr */
    0,                                                 /* tp_setattr */
    0,                                                 /* tp_reserved */
    0,                                                 /* tp_repr */
    0,                                                 /* tp_as_number */
    0,                                                 /* tp_as_sequence */
    0,                                                 /* tp_as_mapping */
    0,                                                 /* tp_hash  */
    0,                                                 /* tp_call */
    0,                                                 /* tp_str */
    PyObject_GenericGetAttr,                           /* tp_getattro */
    PyObject_GenericSetAttr,                           /* tp_setattro */
    0,                                                 /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,          /*tp_flags*/
    "PyCamera",                                        /* tp_doc */
    0,                                                 /* tp_traverse */
    0,                                                 /* tp_clear */
    0,                                                 /* tp_richcompare */
    0,                                                 /* tp_weaklistoffset */
    0,                                                 /* tp_iter */
    0,                                                 /* tp_iternext */
    instance_methods,                                  /* tp_methods */
    0,                                                 /* tp_members */
    0,                                                 /* tp_getset */
    0,                                                 /* tp_base */
    0,                                                 /* tp_dict */
    0,                                                 /* tp_descr_get */
    0,                                                 /* tp_descr_set */
    0,                                                 /* tp_dictoffset */
    0,                                                 /* tp_init */
    0,                                                 /* tp_alloc */
    PyCamera_new,                                      /* tp_new */
};

Mentakrifkan struct PyWindow yang membalut objek C CameraWindow. Ahli pengendali menunjuk pada contoh CameraWindow.

Kaedah untuk Objek PyWindow

• PyWindow_dealloc
  

  #include <Python.h>
  #include <structmember.h>
  #include "CameraPreview.h"
  

  Mengagihkan objek CameraWindow dan melepaskan memori.

• PyWindow_new
  

  typedef struct
  {
      PyObject_HEAD CameraWindow *handler;
  } PyWindow;
  
  

  Mencipta tika baharu PyWindow. Ia memperuntukkan memori untuk objek Python, mencipta objek CameraWindow baharu dan menugaskannya kepada pengendali diri>.

• Kunci tunggu
  

  python-lite-camera
  │
  │── include
  │   ├── Camera.h
  │   ├── CameraPreview.h
  │   ├── stb_image_write.h
  │── lib
  │   ├── linux
  │   │   ├── liblitecam.so
  │   ├── macos
  │   │   ├── liblitecam.dylib
  │   ├── windows
  │   │   ├── litecam.dll
  │   │   ├── litecam.lib
  ├── src
  │   ├── litecam.cpp
  │   ├── pycamera.h
  │   ├── pywindow.h
  │── litecam
  │   ├── __init__.py
  │── setup.py
  │── MANIFEST.in
  │── README.md
  

  Menunggu acara tekan kekunci dan mengembalikan False jika kekunci sepadan dengan aksara yang ditentukan. False bermaksud aplikasi harus keluar.

• Rangka persembahan
  

  from setuptools.command import build_ext
  from setuptools import setup, Extension
  import sys
  import os
  import io
  from setuptools.command.install import install
  import shutil
  from pathlib import Path
  
  lib_dir = ''
  
  sources = [
      "src/litecam.cpp",
  ]
  
  include_dirs = [os.path.join(os.path.dirname(__file__), "include")]
  
  libraries = ['litecam']
  
  extra_compile_args = []
  
  if sys.platform == "linux" or sys.platform == "linux2":
      lib_dir = 'lib/linux'
      extra_compile_args = ['-std=c++11']
      extra_link_args = ["-Wl,-rpath=$ORIGIN"]
  elif sys.platform == "darwin":
      lib_dir = 'lib/macos'
      extra_compile_args = ['-std=c++11']
      extra_link_args = ["-Wl,-rpath,@loader_path"]
  elif sys.platform == "win32":
      lib_dir = 'lib/windows'
      extra_link_args = []
  
  else:
      raise RuntimeError("Unsupported platform")
  
  
  long_description = io.open("README.md", encoding="utf-8").read()
  
  module_litecam = Extension(
      "litecam",
      sources=sources,
      include_dirs=include_dirs,
      library_dirs=[lib_dir],
      libraries=libraries,
      extra_compile_args=extra_compile_args,
      extra_link_args=extra_link_args,
  )
  
  def copyfiles(src, dst):
      if os.path.isdir(src):
          filelist = os.listdir(src)
          for file in filelist:
              libpath = os.path.join(src, file)
              shutil.copy2(libpath, dst)
      else:
          shutil.copy2(src, dst)
  
  
  class CustomBuildExt(build_ext.build_ext):
      def run(self):
          build_ext.build_ext.run(self)
          dst = os.path.join(self.build_lib, "litecam")
          copyfiles(lib_dir, dst)
          filelist = os.listdir(self.build_lib)
          for file in filelist:
              filePath = os.path.join(self.build_lib, file)
              if not os.path.isdir(file):
                  copyfiles(filePath, dst)
                  os.remove(filePath)
  
  
  class CustomBuildExtDev(build_ext.build_ext):
      def run(self):
          build_ext.build_ext.run(self)
          dev_folder = os.path.join(Path(__file__).parent, 'litecam')
          copyfiles(lib_dir, dev_folder)
          filelist = os.listdir(self.build_lib)
          for file in filelist:
              filePath = os.path.join(self.build_lib, file)
              if not os.path.isdir(file):
                  copyfiles(filePath, dev_folder)
  
  
  class CustomInstall(install):
      def run(self):
          install.run(self)
  
  
  setup(name='lite-camera',
        version='2.0.1',
        description='LiteCam is a lightweight, cross-platform library for capturing RGB frames from cameras and displaying them. Designed with simplicity and ease of integration in mind, LiteCam supports Windows, Linux and macOS platforms.',
        long_description=long_description,
        long_description_content_type="text/markdown",
        author='yushulx',
        url='https://github.com/yushulx/python-lite-camera',
        license='MIT',
        packages=['litecam'],
        ext_modules=[module_litecam],
        classifiers=[
             "Development Status :: 5 - Production/Stable",
             "Environment :: Console",
             "Intended Audience :: Developers",
            "Intended Audience :: Education",
            "Intended Audience :: Information Technology",
            "Intended Audience :: Science/Research",
            "License :: OSI Approved :: MIT License",
            "Operating System :: Microsoft :: Windows",
            "Operating System :: MacOS",
            "Operating System :: POSIX :: Linux",
            "Programming Language :: Python",
            "Programming Language :: Python :: 3",
            "Programming Language :: Python :: 3 :: Only",
            "Programming Language :: Python :: 3.6",
            "Programming Language :: Python :: 3.7",
            "Programming Language :: Python :: 3.8",
            "Programming Language :: Python :: 3.9",
            "Programming Language :: Python :: 3.10",
            "Programming Language :: Python :: 3.11",
            "Programming Language :: Python :: 3.12",
            "Programming Language :: C++",
            "Programming Language :: Python :: Implementation :: CPython",
            "Topic :: Scientific/Engineering",
            "Topic :: Software Development",
        ],
        cmdclass={
            'install': CustomInstall,
            'build_ext': CustomBuildExt,
            'develop': CustomBuildExtDev},
        )
  

  Memaparkan bingkai dalam tetingkap.

• drawContour
  

  #include <Python.h>
  #include <structmember.h>
  #include "Camera.h"
  

  Melukis kontur (siri titik) pada bingkai.

• drawTeks
  

  typedef struct
  {
      PyObject_HEAD Camera *handler;
  } PyCamera;
  

  Melukis teks pada bingkai.

window_instance_methods

static int PyCamera_clear(PyCamera *self)
{
    if (self->handler)
    {
        delete self->handler;
    }
    return 0;
}

static void PyCamera_dealloc(PyCamera *self)
{
    PyCamera_clear(self);
    Py_TYPE(self)->tp_free((PyObject *)self);
}

Mentakrifkan kaedah yang tersedia pada objek Python PyWindow.

PyWindowType

static PyObject *PyCamera_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
    PyCamera *self;

    self = (PyCamera *)type->tp_alloc(type, 0);
    if (self != NULL)
    {
        self->handler = new Camera();
    }

    return (PyObject *)self;
}

Mentakrifkan jenis PyWindow, termasuk kaedahnya, peruntukan memori, deallocation dan gelagat lain.

litecam.cpp

static PyObject *open(PyObject *obj, PyObject *args)
{
    PyCamera *self = (PyCamera *)obj;

    int index = 0;
    if (!PyArg_ParseTuple(args, "i", &index))
    {
        return NULL;
    }

    bool ret = self->handler->Open(index);
    return Py_BuildValue("i", ret);
}

Penjelasan:

• getDeviceList: Mengembalikan senarai kamera yang tersedia.
• saveJpeg: Menyimpan bingkai sebagai imej JPEG.
• PyInit_litecam: Memulakan modul litecam dan mendaftarkan jenis PyCamera dan PyWindow.

Membina SDK Kamera Python

• Mod Pembangunan
  

  static PyObject *listMediaTypes(PyObject *obj, PyObject *args)
  {
      PyCamera *self = (PyCamera *)obj;
  
      std::vector<MediaTypeInfo> mediaTypes = self->handler->ListSupportedMediaTypes();
  
      PyObject *pyList = PyList_New(0);
  
      for (size_t i = 0; i < mediaTypes.size(); i++)
      {
          MediaTypeInfo &mediaType = mediaTypes[i];
  
  #ifdef _WIN32
          PyObject *subtypeName = PyUnicode_FromWideChar(mediaType.subtypeName, wcslen(mediaType.subtypeName));
          PyObject *pyMediaType = Py_BuildValue("{s:i,s:i,s:O}",
                                                "width", mediaType.width,
                                                "height", mediaType.height,
                                                "subtypeName", subtypeName);
          if (subtypeName != NULL)
          {
              Py_DECREF(subtypeName);
          }
  
  #else
          PyObject *pyMediaType = Py_BuildValue("{s:i,s:i,s:s}",
                                                "width", mediaType.width,
                                                "height", mediaType.height,
                                                "subtypeName", mediaType.subtypeName);
  #endif
  
          PyList_Append(pyList, pyMediaType);
      }
  
      return pyList;
  }
  
  

• Pakej Roda
  

  static PyObject *release(PyObject *obj, PyObject *args)
  {
      PyCamera *self = (PyCamera *)obj;
  
      self->handler->Release();
      Py_RETURN_NONE;
  }
  

• Pengagihan Sumber
  

  static PyObject *setResolution(PyObject *obj, PyObject *args)
  {
      PyCamera *self = (PyCamera *)obj;
      int width = 0, height = 0;
      if (!PyArg_ParseTuple(args, "ii", &width, &height))
      {
          return NULL;
      }
      int ret = self->handler->SetResolution(width, height);
      return Py_BuildValue("i", ret);
  }
  

Langkah-langkah untuk Melaksanakan Pengimbas Berbilang Kod Bar Python

1. Pasang SDK kamera Python dan SDK Pembaca Kod Bar Dynamsoft:
   

   static PyObject *captureFrame(PyObject *obj, PyObject *args)
   {
       PyCamera *self = (PyCamera *)obj;
   
       FrameData frame = self->handler->CaptureFrame();
       if (frame.rgbData)
       {
           PyObject *rgbData = PyByteArray_FromStringAndSize((const char *)frame.rgbData, frame.size);
           PyObject *pyFrame = Py_BuildValue("iiiO", frame.width, frame.height, frame.size, rgbData);
           ReleaseFrame(frame);
   
           return pyFrame;
       }
       else
       {
           Py_RETURN_NONE;
       }
   }
   

2. Dapatkan lesen percubaan percuma selama 30 hari untuk Pembaca Kod Bar Dynamsoft.

3. Buat skrip Python untuk pengimbasan berbilang kod bar:
   

   static PyObject *getWidth(PyObject *obj, PyObject *args)
   {
       PyCamera *self = (PyCamera *)obj;
   
       int width = self->handler->frameWidth;
       return Py_BuildValue("i", width);
   }
   
   static PyObject *getHeight(PyObject *obj, PyObject *args)
   {
       PyCamera *self = (PyCamera *)obj;
   
       int height = self->handler->frameHeight;
       return Py_BuildValue("i", height);
   }
   

   Ganti LESEN-KUNCI dengan kunci lesen Pembaca Kod Bar Dynamsoft anda.

4. Jalankan skrip:
   

   static PyMethodDef instance_methods[] = {
       {"open", open, METH_VARARGS, NULL},
       {"listMediaTypes", listMediaTypes, METH_VARARGS, NULL},
       {"release", release, METH_VARARGS, NULL},
       {"setResolution", setResolution, METH_VARARGS, NULL},
       {"captureFrame", captureFrame, METH_VARARGS, NULL},
       {"getWidth", getWidth, METH_VARARGS, NULL},
       {"getHeight", getHeight, METH_VARARGS, NULL},
       {NULL, NULL, 0, NULL}};
   
   

   

Kod Sumber

https://github.com/yushulx/python-lite-camera

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