花落阳关

1 hour ago, hatef said:

use this vi to search and find camera 

I have several cameras, but it only shows one, how to solve the problem? 

Hi! I had write a lv program and generate a .exe file. But once open the exe file, it will run the program,  owing to it need time to find the camera so something wrong will happen. Now I want to add a function for searching the camera, led on light when it had found the camera to give a notice, then it will autorun to acquire figures. So the question is how to add the camera earch function ? Thanks 

On 2017/12/14 at 10:16 PM, bmoyer said:

LV2011 in case others have the same difficulty.

Call HandBrake.vi

It does't work, I don't know why? Can you solve the problem, thanks!

Call HandBrake (2).vi

1 hour ago, ensegre said:

Dataflow.The small loop runs only after the big acquisition loop ends. You probably have no choice but to communicate the avi file reference and the writing status from one to the other via local variables. Or a channel wire perhaps.

I just want to add three button(grab,save and stop).Press grab to start to display on the front panel, press save button to generate a avi file(not generate one when the button is not pressed),press again to end the save mode. Press stop to end the whole program, could you please help me modify it, I had tried many times. 

On 2017/12/10 at 1:13 AM, ensegre said:

Basic LV programming question. One way is with event frames. You should only open the AVI file when the boolean changes from false to true and close it when it reverts to false.

Now there is still some question with the program, it can not be wrote to avi, just the last frame,I don't know why. Help me modify it to run, thanks!

Grab and SAVE AVI.vi

22 hours ago, bmoyer said:

You can include HandBrakeCLI.exe in the installer of your application and make calls to the exe using the command line interface.

Call HandBrake.vi

Thanks, can you generate the vi as 2015 version, I can not open it.

On 2017/12/10 at 1:04 AM, ensegre said:

http://zone.ni.com/reference/en-XX/help/370281AD-01/imaqvision/imaq_avi2_create/

http://zone.ni.com/reference/en-XX/help/370281AD-01/imaqvision/imaq_avi2_get_codec_names/

Thanks, I know the two vi, but I had install a h.264 and FFMPEG encoder, but it can't be found in the system, I don't know what's wrong with the question. I had tried to compare the video size of many video encoder and investigated in the website, the result is h.264 encoder is the best, it offers the minimum size  with guaranteeing image quality. So how can install the h.264 encoder and found it in the system?

Thanks for your suggestion, but it is a exe file, cannot be used in the labview program, I need a H.264 dll file or a  encapsulated function API for calling. And another question there is only one video type(avi format), if I had  encapsulated a dll file, whether or not it must firstly generate a avi file, then convert to mp4. Or maybe I have to encapsulated there function(create mp4 flie, acquire mp4, and close mp4 file), it's very hard for me.

10 hours ago, bmoyer said:

I use the Command Line Interface of Handbrake to allow LabVIEW to convert the .avi to .mp4 but I'm sure there are better ways.  

https://handbrake.fr/

 

 

Hi! Now I am writing a real time acquire and save to video file program.But 1080*720, 30 fps, it generates a lot of video data via the camera, about 20s for 1G bits. H.264 is a open source encode, how can I use the encoder to convert avi to mp4 or directly generate a mp4 file, has anyone who had achieved the effect?Thanks!

On 2017/12/6 at 3:56 PM, ensegre said:

I don't see a producer-consumer in your VI. That is e.g. two loops, enqueueing and dequeueing image references, or something equivalent. You create an AVI file at start because your program does so, you might want to do it rather only after the button is pressed. And I would handle that with an event structure and a shift register propagating the file reference from one iteration to the next. Maybe you'd want to check some LV learning resource first?

Thanks, I had achieved the result using the  producer-consumer,you can see it in the vi file. But I wanna to pressed the Boolean 2-5 to create avi files, otherwise it while generate many empty file, but the present program can just be pressed once, because the corresponding while structure will be end up. When I want to modify file name to generate a new avi file, it cannot be run(because it just could run once).So now I have two questions:

1. How to modify the program to achieve  continuous operation to generate a new avi file?

2. The pixels are 1080*720, 30 fps, 20s could generate 2G data, how can I  achieve compression and transmission of videos,then decoding and saving the avi file?

save avi.vi

16 hours ago, ensegre said:

A producer-consumer architecture, with a queue of images to be saved by the consumer loop, is the first thing you should really try. Alternatively and asynchronously grabbing one image from each loop for either viewing or saving, like you do, wont bring you far. Also, rendering the preview image might be resource intensive and compete with saving, you may want to display only one every N images. Finally, AVI could involve compression codecs, which can also be computationally demanding; to maintain a given frame rate you might have to stream uncompressed images, or to choose a less demanding codec, to reduce the image size.

Thanks, I can achieve the result via use the producer-consumer architecture with a better frame rate. But now there is a question, everytime run the program it will automatically generate a .avi file and it always be a empty file(0 byte).Now I want to add a case structure, when the case button was pressed it save to a avi file.If it was not pressed,the empty file won't be generate. You can directly modify in the vi file,thanks!

Grab and save avi.vi

Hello, everyone!

I want to  synchronous acquire and save video files via a GIGE camera while not influence the frame rate. I achieve the program as below, but the frame rate is highly unstable. I hope you can offer some ideas, thanks!

Hello, everyone!

I have a question with the waveform chart(figure 1). How can I plot multi curves in a waveform chart in sequence (figure 2)?

For example：

1. I plot the first curve which the starting point is 0.

2.I stop the program or press a button, then the second curve plots from the starting point at 0, too.

3. And so on, I can plot some cures in the same waveform chart.

I am looking forward to a reply, thanks for your attention !

10 hours ago, ShaunR said:

Did you save your 1.png as an 8bit  greyscale image?

Try with mine.

Sorry, the image of the 1.png is RGB, so I can not get the result.I had tried the 8 bit grayscale image,it's no problem, thanks!But I have two questions :1.the upper part of the vi just change the colortable of the intensity graph,why the intensity graph can add false-color? 2.I want to add false-color into the image display in real-time mode,how can I use the avaliable LUT? Below is image display, not intensity graph.Thanks!

18 hours ago, smithd said:

If you have the vision development module, there is a function for the built-in options: C:\Program Files (x86)\National Instruments\LabVIEW 2015\vi.lib\vision\Display.llb\IMAQ GetPalette

Useful if someone wants to replicate the behavior of the imaq image display.

Hi, smithd!

  I konw this vi, but there is just five color mode in the vi. I want to load the avaliable LUT into the image display.I do not kow how to use get colorpalette,can you upload a vi ?Thanks!

Hi,ShaunR!

   I can not realize the result of yours, it just change the colortable of the intensity graph,not show the false-color in the intensity graph(nothing in it). So how to show false-color? 

Hello,everyone!

I want  to use LabVIEW to make grayscale images convert to  pseudo-color image by using lookup table.But I do not know how to use this function. How can I  customize a LUT function ?I had find a lot of lut files from imageJ ,can I load the  available lut files into LabVIEW ?Thanks!