Hello, I try to bind C++ OpenCV version to understand how to made it. So I
created a little "useless" Nim file:
{.passc: "-I/mnt/c/OpenCVNim/extern/opencv-install/include/opencv4", link:
"/mnt/c/OpenCVNim/extern/opencv-install/lib/libopencv_world.so".}
const
mat = "<opencv2/core/mat.hpp>"
imgcodecs = "<opencv2/imgcodecs.hpp>"
type
Mat {.importcpp: "cv::Mat", header: mat.} = object
ImreadModes = enum
IMREAD_UNCHANGED = -1, ## !< If set, return the loaded image
as is (with alpha channel, otherwise it gets cropped). Ignore EXIF orientation.
IMREAD_GRAYSCALE = 0, ## !< If set, always convert image to
the single channel grayscale image (codec internal conversion).
IMREAD_COLOR = 1, ## !< If set, always convert image to
the 3 channel BGR color image.
IMREAD_ANYDEPTH = 2, ## !< If set, return 16-bit/32-bit
image when the input has the corresponding depth, otherwise convert it to 8-bit.
IMREAD_ANYCOLOR = 4, ## !< If set, the image is read in any
possible color format.
IMREAD_LOAD_GDAL = 8, ## !< If set, use the gdal driver for
loading the image.
IMREAD_REDUCED_GRAYSCALE_2 = 16, ## !< If set, always convert image
to the single channel grayscale image and the image size reduced 1/2.
IMREAD_REDUCED_COLOR_2 = 17, ## !< If set, always convert image to
the 3 channel BGR color image and the image size reduced 1/2.
IMREAD_REDUCED_GRAYSCALE_4 = 32, ## !< If set, always convert image
to the single channel grayscale image and the image size reduced 1/4.
IMREAD_REDUCED_COLOR_4 = 33, ## !< If set, always convert image to
the 3 channel BGR color image and the image size reduced 1/4.
IMREAD_REDUCED_GRAYSCALE_8 = 64, ## !< If set, always convert image
to the single channel grayscale image and the image size reduced 1/8.
IMREAD_REDUCED_COLOR_8 = 65, ## !< If set, always convert image to
the 3 channel BGR color image and the image size reduced 1/8.
IMREAD_IGNORE_ORIENTATION = 128
proc imread(file: cstring, mode: ImreadModes): Mat {.importcpp:
"cv::imread(@)", header: imgcodecs.}
proc imwrite(file: cstring, mat : Mat): bool {.importcpp:
"cv::imwrite(@)", header: imgcodecs.}
when isMainModule:
var
imagePath : cstring =
"/mnt/c/OpenCVNim/extern/opencv-4.5.5/samples/data/box.png"
img = imread(imagePath, IMREAD_COLOR);
discard imwrite("/mnt/c/OpenCVNim/extern/test.jpg", img)
Run
It seems pretty simple but I have a link error:
Verifying dependencies for [email protected]
Info: Dependency on cppstl@any version already satisfied
Verifying dependencies for [email protected]
Building OpenCVNim/OpenCVNim using cpp backend
/usr/bin/ld: /home/echopouet/.cache/nim/OpenCVNim_d/@mOpenCVNim.nim.cpp.o:
in function `NimMainModule()':
@mOpenCVNim.nim.cpp:(.text+0x26f): undefined reference to
`cv::imread(std::__cxx11::basic_string<char, std::char_traits<char>,
std::allocator<char> > const&, int)'
/usr/bin/ld: @mOpenCVNim.nim.cpp:(.text+0x282): undefined reference to
`cv::Mat::operator=(cv::Mat&&)'
/usr/bin/ld: @mOpenCVNim.nim.cpp:(.text+0x28e): undefined reference to
`cv::Mat::~Mat()'
/usr/bin/ld: @mOpenCVNim.nim.cpp:(.text+0x351): undefined reference to
`cv::imwrite(std::__cxx11::basic_string<char, std::char_traits<char>,
std::allocator<char> > const&, cv::_InputArray const&, std::vector<int,
std::allocator<int> > const&)'
/usr/bin/ld: @mOpenCVNim.nim.cpp:(.text+0x3bb): undefined reference to
`cv::Mat::~Mat()'
/usr/bin/ld: /home/echopouet/.cache/nim/OpenCVNim_d/@mOpenCVNim.nim.cpp.o:
in function `__static_initialization_and_destruction_0(int, int)':
@mOpenCVNim.nim.cpp:(.text+0x486): undefined reference to `cv::Mat::Mat()'
/usr/bin/ld: @mOpenCVNim.nim.cpp:(.text+0x49b): undefined reference to
`cv::Mat::~Mat()'
collect2: error: ld returned 1 exit status
Error: execution of an external program failed: 'g++ -o
/mnt/c/OpenCVNim/OpenCVNim
/mnt/c/OpenCVNim/extern/opencv-install/lib/libopencv_world.so
/home/echopouet/.cache/nim/OpenCVNim_d/stdlib_digitsutils.nim.cpp.o
/home/echopouet/.cache/nim/OpenCVNim_d/stdlib_dollars.nim.cpp.o
/home/echopouet/.cache/nim/OpenCVNim_d/stdlib_system.nim.cpp.o
/home/echopouet/.cache/nim/OpenCVNim_d/@mOpenCVNim.nim.cpp.o -ldl'
Tip: 3 messages have been suppressed, use --verbose to show them.
Error: Build failed for package: OpenCVNim
... Execution failed with exit code 1
... Command: /home/echopouet/.nimble/bin/nim cpp --colors:on
--noNimblePath -d:NimblePkgVersion=0.1.0
--path:/home/echopouet/.nimble/pkgs/cppstl-0.5.0 --hints:off
-o:/mnt/c/OpenCVNim/bin/OpenCVNim /mnt/c/OpenCVNim/src/OpenCVNim.nim
Run
I link with **libopencv_world.so** that contains all so I don't undertstand why
all are missing. I certainly missed something.
Thanks.
