I'm trying to use this library https://github.com/dom96/nim-opencv a wrapper for OpenCV.
After running nimble install opencv
I can see the package in ~/.nimble/pkgs/opencv-0.1.0/
But when attempting to use I get a compile error
Error: cannot open 'opencv/highgui'
import opencv/highgui
const fileName = "g.jpg"
let img_colr = loadImage(fileName, 1)
echo img_colr.width
echo img_colr.height
Not sure what the problem is something to do with Nim import paths?...
Are you compiling with nimble or nim? If the former then make sure you've got requires "opencv" in your .nimble file.
Related
I have installed open cv using the official installation process given at:
https://docs.opencv.org/4.5.2/d0/db2/tutorial_macos_install.html
I am doing this on mac and it took ~3 hours for this process. After installation, the installed directory looks like this:
apple#Apples-MacBook-Air.local:~/Learning/openCV/cpp$ pwd
/Users/apple/Learning/openCV/cpp
apple#Apples-MacBook-Air.local:~/Learning/openCV/cpp$ ls
3rdparty CTestTestfile.cmake bin data
opencv_data_config.hpp setup_vars.sh
CMakeCache.txt Makefile cmake_install.cmake doc
opencv_lapack.h test-reports
CMakeDownloadLog.txt OpenCVConfig-version.cmake cmake_uninstall.cmake
include opencv_python_config.cmake tmp
CMakeFiles OpenCVConfig.cmake configured lib
opencv_python_tests.cfg unix-install
CMakeVars.txt OpenCVModules.cmake custom_hal.hpp modules
opencv_tests_config.hpp version_string.tmp
CPackConfig.cmake apps cv_cpu_config.h opencv
python_loader
CPackSourceConfig.cmake basicOp.cpp cvconfig.h opencv2
samples
Now, I am writing a very simple program to test the installation and it looks like that I need to do more things than what I have done so far.
My simple program:
#include<iostream>
#include<opencv2/core.hpp>
int main() {
std::string imagePath = samples.findFile("starry_night.jpg");
cv::Mat imageMatrix = cv::imread(imagePath);
if(imageMatrix.empty()) {
std::cout << "Matrix is empty" << std::endl;
}
}
Compiling this gives error as:
apple#Apples-MacBook-Air.local:~/Learning/openCV/programs$ g++ imageRead.cpp
imageRead.cpp:2:9: fatal error: 'opencv2/core.hpp' file not found
#include<opencv2/core.hpp>
No problem, I can probably understand that due to non-linkage of the open cv libraries.
So, I compiled with:
apple#Apples-MacBook-Air.local:~/Learning/openCV/programs$ g++ imageRead.cpp -I/Users/apple/Learning/openCV/cpp/include -L/Users/apple/Learning/openCV/cpp/lib/
imageRead.cpp:2:9: fatal error: 'opencv2/core.hpp' file not found
#include<opencv2/core.hpp>
And it still give me the same error. Basically, I passed the paths for gcc to consider for linking.
Any suggestions? I can help providing more details on it, if needed.
Did you try #include<opencv2/opencv.hpp> instead of #include<opencv2/core.hpp>?
I am trying to replace python with dart as a scripting language for my tools. I can create a python file anywhere, import global packages and run it but I can't seem to get this working with dart. Do I always need a pubspec.yaml file to run a dart script?
This is the script I am trying to run:
import 'package:http/http.dart' as http;
main(List<String> args) async{
var res = await http.get('https://example.com');
print(res.headers);
}
This is the error I am getting:
Error: Could not resolve the package 'http' in 'package:http/http.dart'.
test2.dart:1:8: Error: Not found: 'package:http/http.dart'
import 'package:http/http.dart' as http;
^
test2.dart:4:19: Error: Method not found: 'get'.
var res = await http.get('https://example.com');
No, you don't need a pubspec.yaml file to run a program, but it does need to somehow be able to resolve all the imports.
The pubspec.yaml file is used for obtaining the packages (from pub.dev, a git repository, etc.) but not for finding the packages at runtime. The pub program reads the pubspec.yaml file and downloads the packages mentioned in it, and maintains a packages specification file indicating where each package resolves to. By default the packages specification is in a file called .packages in the same directory as the pubspec.yaml file. The Dart runtime normally finds the packages by looking at the .packages package specification file, but there are other ways.
Here are some options:
Put a .packages file in the same directory as the Dart program, or in an ancestor directory.
Use the --packages option to specify the package specification file to use:
dart --packages=/home/username/stuff/mypackagespecfile myprogram.dart
The Dart runtime also has a --package-root option. But I haven't figured out how to make it work.
The import statements use URIs, so import 'file://...'; can also work in some cases.
Use dart2native to compile the program into an executable.
Note: Dart scripts can also start with a hash-bang line:
#!/usr/bin/env dart
import 'package:http/http.dart' as http;
main(List<String> args) async{
var res = await http.get('https://example.com');
print(res.headers);
}
Then you can make the program executable and run it without needing to type in the Dart runtime:
$ chmod a+x myprogram.dart
$ ./myprogram.dart
I try to run in VSCode a simple dart program with
import 'dart:html';
clause.
import 'dart:html';
// import 'package:html/dom.dart';
// import 'package:html/dom_parsing.dart';
// import 'package:html/parser.dart';
void main() async{
var myTable = new TableElement()
..setAttribute('border','1');
// ..setAttribute(name, value);
...
In Run mode (I use VSCode extension "Code Runner 0.9.9") and in Debug appeared the same error:
Error: Not found: 'dart:html'
import 'dart:html';
I have installed Dart SDK 2.3.1 at Windows10 and not installed Flutter at all.
PATH pointed to Dart SDK bin directory
PATH =D:\Dart\dart-sdk\bin;
*) At project directory I try to add additional directive at pubspec.yaml
dependencies:
----
name: main
description: Test App sample22
dependencies:
html:
---
After "pub get" command I'll see that html present but error still persist.
pub get
Resolving dependencies...
+ charcode 1.1.2
+ csslib 0.16.0
+ html 0.14.0+2
+ path 1.6.2
+ source_span 1.5.5
+ term_glyph 1.1.0
Changed 6 dependencies!
*) My next step was to import html parts via "package:html/" (marked as comments in code sample). It is not helped and required class TableElement still unrecognizable.
"main.dart:8:19: Error: Method not found: 'TableElement'."
*) I try to change "launch.json" string from
default
"program": "bin/main.dart",
to
"program": "D:/Dart/WRK03t/main.dart",
And rename my code file to "main.dart"
*) Also I try to remove Dart extension from VSCode, restart PC and install it again. it's not helped.
But let me say that when I compile main.dart to js
"dart2js -m -o tst.js main.dart"
Resulted tst.js run correctly within the html page.
Almost the same problem in Request Dart Installation doesnt find dart:html
dart:html is only available in the browser. This is the error you get if you try to run code that uses it on the VM (instead of the browser). This is expected.
If you need to run your code outside of the browser (eg. in the VM as a CLI app or via Fluter) you cannot use dart:html. If you only want to use it in the browser but VS Code is trying to run your code in the VM, you'll need to set up some VS Code tasks/launch configs to run build_runner, similar to the Dart DevTools project:
https://github.com/flutter/devtools/tree/abe811f66e1bd36612b76bbe28250bc669a6ce08/.vscode
Where need I to set the path to the protoc to get import standards Protocol Buffers (protobuf), like empty.proto and timestamp.proto in Windows and Dart?
When the protoc is ran:
protoc --dart_out=grpc:lib/src/protos/generated -Iprotos
protos/organization.proto
--plugin=protoc-gen-dart=D:\Users\Samuel\AppData\Roaming\Pub\Cache\bin\protoc-gen-dart.bat
The following error is presented:
google/protobuf/empty.proto: File not found. organization.proto:
Import "google/protobuf/empty.proto" was not found or had errors.
organization.proto:14:27: "google.protobuf.Empty" is not defined.
In IntelliJ Settings on Protobuf Support plugin the path is define where standard protos (*.proto) are:
Additionally this path is define in IntelliJ on Project Structure \ Global Libraries:
The code organization.proto that import google/protobuf/empty.proto to use Empty class :
syntax = "proto3";
package auge.protobuf;
import "google/protobuf/empty.proto";
service OrganizationService {
rpc GetOrganizations (google.protobuf.Empty) returns (OrganizationsResponse) {}
}
IntelliJ analyzer recognizes the import "google/protobuf/empty.proto" and Empty class on IDEA, but protoc can not find.
The environment is:
SO: Windows 7 x64
protoc: libprotoc 3.6.1
Dart: 2.2.0-edge
Say you have /some/path/to/google/protobuf/empty.proto, you need to pass --proto_path=/some/path/to/ so protoc can locate it.
use two dot before protobuf folder path
<Protobuf Include="..\Proto\protobuf.proto" ProtoRoot="Proto" />
I've follow the instructions for dart libsass at:
https://github.com/oddrationale/dart_libsass
The compile step completes correctly. However - when i try and execute sassd.dart i get the following:
dart bin/sassd.dart ~/projects/web_apps_dart/lib/client/components/picker/picker.scss ~/Desktop/test.css
Cannot find extension library'package:libsass/libsass.dart': error: line 10 pos 1: library handler failed
import 'dart-ext:libsass/src/sass_extension';
^
Cannot find initialization function in extension'package:libsass/libsass.dart': error: line 10 pos 1: library handler failed
import 'dart-ext:sass_extension';
^
sass_extension.cc exists at ~/lib/src/sass_extension.cc
Question: How do we correctly import the sass_extions.cc file in recent builds of Dart?
I'm the author/maintainer of dart_libsass.
I got your bug report on GitHub and resolved the issue there. The issue was with the build script not the sass_extension.cc file itself. If you have any other issues, let's continue the discussion on the GitHub issues page. Thanks!