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Kazunari Kudo edited this page Jan 16, 2020 · 39 revisions

I would like to install a specific version of Harvester. How should I do it?

I would like to install a specific version of Harvester. How should I do it?

Answer

If you want to install the latest version in the version 0 line, then execute the following command:

$ pip uninstall harvesters
$ pip install harvesters<1 -U --no-cache-dir

As always, it is better to learn from the original source:

https://pip.pypa.io/en/stable/reference/pip_install/#id49

Why doesn't the device have the GenICam feature nodes that I want to work with?

I think I'm accessing my camera but it does not have any GenICam feature node that I am expecting to work with.

Answer

Maybe you are accessing a GenTL Device module instead of the physical remote device i.e. the camera.

To get the node map of the remote device, you must code as follows:

node_map = ia.remote_device.node_map

Instead of:

node_map = ia.device.node_map

The latter code returns you the node map that the GenTL Device module holds. Their names are very similar but note that they are not identical. The distinguish had been introduced at version 0.2.12 resolving issue #84:

https://github.com/genicam/harvesters/issues/84

Harvester fails to load TLSimu. What's happening?

I'm trying to get Harvester working with TLSimu on Windows but it always gives me the following error message:

2019-12-03 10:13:38,332 :: harvesters.core :: ERROR :: GenTL exception: Failed to load CTI file; The specified module could not be found.
 (ID: -10001)
Traceback (most recent call last):
  File "c:\users\kkudo\appdata\local\programs\python\python37\lib\site-packages\harvesters\core.py", line 2606, in update_device_info_list
    self._open_gentl_producers()
  File "c:\users\kkudo\appdata\local\programs\python\python37\lib\site-packages\harvesters\core.py", line 2483, in _open_gentl_producers
    producer.open(file_path)
  File "c:\users\kkudo\appdata\local\programs\python\python37\lib\site-packages\genicam2\gentl.py", line 2306, in open
    return _gentl.GenTLProducer_open(self, path_name)
_gentl.LoadLibraryException: GenTL exception: Failed to load CTI file; The specified module could not be found.
 (ID: -10001)

Answer

TLSimu is used to test the functionalities of Harvester and TLSimu has a dependency on a DLL called VirtualFG. To get Harvester working with TLSimu, you must make VirtualFG visible from it's DLL search order.

An intuitive solution would be to add the file location to the PATH environment variable.

See also

Dynamic-Link Library Search Order

I'd like to store the downloaded XML/Zip file. How can I do that?

I would like to store the downloaded XML/Zip file of the target devices. How can I do that?

Answer

You can use an environment variable, HARVESTERS_XML_FILE_DIR, to specify the directory where downloaded Zip/XML files are stored. Set a directory to the variable and then execute your program that uses Harvester. You will find the expected file in the specified location when the program tried to create an ImageAcquirer object.

I'm trying to involve 2 or more netowrk interface cards but it corrupts my program. Why?

My program involves 2 or more network interface cards, NICs in short. However, everything is fine as long as I use only a single NIC but my program turns corrupted once I started to use 2 or more network interface cards. Why is this issue happening?

Answer

Assign individual subnet to each NIC. They should not reside in the same subnet.

See also

Microsoft: How multiple adapters on the same network are expected to behave

How can I check the version number of Harvester?

I'm using Harvester and would like to know its version number.

Answer

You can check the version number referring to the __version__ property. The code would like as follows:

from harvesters import __version))
print(__version__)

It would give you a string, for example:

'0.2.8'

Harvester raises ClosedException but I don't know why

I'm just creating ImageAcquirer objects passing a factory method a Harvester object:

class Foo:
    def create_image_acquirer(harvester: Harvester, index: int):
        return harvester.create_image_acquirer(id_=index)

However, Harvester unexpectedly raises ClosedException. Why?

Exception ignored in: <function ImageAcquirer.__del__ at 0x0000019F2A2E8C80>
Traceback (most recent call last):
  File "C:\Python37\lib\site-packages\harvesters\core.py", line 1383, in __del__
    self.destroy()
  File "C:\Python37\lib\site-packages\harvesters\core.py", line 1968, in destroy
    self._parent._destroy_image_acquirer(self)
  File "C:\Python37\lib\site-packages\harvesters\core.py", line 2489, in _destroy_image_acquirer
    id_ = ia._device.id_
  File "C:\Python37\lib\site-packages\genicam2\gentl.py", line 3238, in _get_id_
    return _gentl.Device__get_id_(self)
_gentl.ClosedException: GenTL exception: Tried to call a function but the library has been closed. Call GCInitLib first. (ID: -10002)

Answer

A possible short answer is you don't hold the Harvester object while the created ImageAcquirer objects.

Nothing wrong with creating ImageAcquirer objects calling a factory method but if the Foo object reaches out to its life although the ImageAcquirer objects will keep existing, the C++ objects of each Python ImageAcquirer object will be automatically destructed by design.

Having that destruction, the ImageAcquirer objects turn dangling and any operation on the objects lose meaning because it's C++ object has gone.

Again, please keep holding the Harvester object as long as you keep holding ImageAcquirer objects.

I want to upgrade Harvester to an arbitrary version

How can I upgrade Harvester to an arbitrary version using pip?

Answer

You can upgrade/downgrade Harvester just typing as follows; if you want to upgrade to 0.2.0 then:

$ pip install harvesters==0.2.0

I want to identify the dependency of the installed Python packages

It's not always but sometimes I need to check the dependencies of the Python packages that I installed using pip. Is there any way to easily make it?

Answer

Maybe pipdeptree could help you. You can install pipdeptree typing the following command:

$ pip install pipdeptree

After installed that, type the following command:

$ pipdeptree

It will display the dependency tree.

I pointed out a CTI file but Harvester says the image doesn't exist (Part 2)

Following the "Getting Started" page, I copied a CTI file to my location and actually pointed out the location where my target CTI files are located as follows:

h = Harvester()
h.add_cti_file('my_target.cti')
h.update_device_info_list()
_gentl.LoadLibraryException: GenTL exception: Failed to load CTI file; The specified module could not be found. (ID: -10001)

Answer

A CTI file is a shared library actually. So PLEASE DO NOT USE THE COPIED CTI FILE!! PLEASE!! Library manufacturers provide you CTI files in appropriate locations because the libraries may need to retrieve relevant libraries to link. If you use the copied one, it may be located in an incorrect location where the library can't load other relevant libraries.

I pointed out a CTI file but Harvester says the image doesn't exist (Part 1)

Following the "Getting Started" page, I actually pointed out the location where my target CTI files are located as follows:

h = Harvester()
h.add_cti_file('c:\path\to\my_target.cti')
h.update_device_info_list()
_gentl.LoadLibraryException: GenTL exception: Failed to load CTI file; The specified module could not be found. (ID: -10001)

Answer

If you want to describe a file path using the Windows style directory separator, you will have to use \\ instead of \. I mean you had to code as follows:

h = Harvester()
h.add_cti_file('c:\\path\\to\\my_target.cti')

Or, the UNIX style is also a way to go:

h.add_cti_file('c:/path/to/my_target.cti')

I actually loaded a .cti file but Harvester returns me an error

Following the "Getting Started" page, I actually pointed out the location where my target CTI files are located as follows:

h = Harvester()
h.add_cti_file('/path/to/my_target.cti')
h.update_device_info_list()

However, Harvester raises the following exception.

_gentl.LoadLibraryException: GenTL exception: Failed to load CTI file; /home/server/Desktop/ctifiles/GxGVTL.cti: invalid ELF header (ID: -10001)

Answer

Are you sure the CTI file was generated for your target operating system? In general, CTI files are system dependent and usually don't work on other operating systems; so the Windows version works only on Windows and the others as well. Actually, CTI files are shared objects or DLLs that renamed the file extension to cti. Please make sure if the CTI file is generated for your target operating system.

Images in .rst files are not displayed on my web browser

Any image in .rst files is not correctly displayed on my web browser while I'm trying it at my office. However, they are actually displayed if I browse them on my private laptop. What is the difference?

Answer

Perhaps your company's Proxy server could be blocking you to access the resources in the GitHub domain. In this case, you should browse the .rst file locally.

First, you should clone the repository:

Then install a restructured text file browser called restview:

$ pip install restview

Finally, open the README.rst in your working copy from it:

$ restview README.rst

restview will open your default web browser and show the contents of the .rst file. In the displayed contents the images in the .rst file should be correctly displayed.

Clone this wiki locally