Iterative pattern matching
Hi, I need to create a pattern matching program. I have successfully created one that matches a template image to a full video. Now, I need a program that updates the template image with each frame. So I would create the template on frame 1. Then on frame 2, when the program finds a spot that matches the template, it saves this image as the new template to compare to the next frame. This would continue for the full video. Does anyone have a program that does this? Or any idea where to start? I am using Labview 2010. Thank you!
Here is my current program!
Attachments:
20120417 Tracking.vi 588 KB
Similar Messages
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Slowness of color pattern matching vi
Hi,
We're trying to implement a SLAM (simultaneous localization and mapping) algorithm in Labview based on kinect. In order to do so, the mapping robot should spot landmarks in real-time from the kinect image. We found the color pattern matching VI which does exactly what we need but the problem is that it's very slow (about 1.5 seconds for each image and total of 3 images each iteration). Is this the normal time for detecting landmarks in a kinect image? The robot can't map accurately when the iteration is so slow.
Thanks,
Rap Master
Attachments:
detect landmarks.vi 61 KBGiven that the pattern matching VI is an IMAQ (Image Acquisition) VI, this question will be best served by posting in our Machine Vision forums.
Blake C.
Applications Engineer
National Instruments
www.ni.com/support -
How can I load pattern matching images into memory?
I discovered this problem by accident when our network went down. I could not run my VI because the .png file used for pattern matching was on a network drive. My concern it the amount of time that is required to read a network file. Is there a way to load the file into memory when the VI is opened?
Brian,
Thank you for contacting National Instruments. For most pattern matching programs, the pattern file should only be read from file once and is then copy to a buffer on the local machine. If you examine your code, or an example program for pattern matching, you should see at least two IMAQ Create VI called somewhere near the front of your code. This VI basically creates a memory location and most likely will be called once for your pattern image and once for the image you are searching.
Unless you are specifically calling a File Dialog VI where you are given a dialog box to open a file or have hard coded the file path so that it is read each iteration of your code, then your pattern file should only need to be called at the beginning of your application, th
us causing only one file read over the network for that image. Therefore your program most likely already loads the image in memory once it is read and should not be accessing the network constantly.
Again, I would recommend taking a look at your code to make sure you are not causing a file access every time and then you should be ready to go. Just in case you do have the network go down, I would recommend keeping a copy of the image locally and, if you are feeling ambitious, you can programmatically have your program read the file locally if the network file returns an error.
Good luck with your application and let us know if we can be of any further assistance.
Regards,
Michael
Applications Engineer
National Instruments -
Problem while using color pattern matching
Currently we are doing projects on real time object tracking where we found one doubt that irrespective of the object size whether this color pattern match works or not . My questions are as follows:
1. Whether it is applicable for objects moving far . Because as it moves far, the size of the object decreases such that the color pattern matching is not working what will be solution since we must use color image
2. What is the difference in using scale and rotate invarient in color pattern matching
3. How we can effectively decrease the ROI depending upon the object position as per below attached screen shots .
we have removed boundary box values of X and Y coordinates at the four corner but we can't track as the object moves far away or we can't decrease the ROI as the object moves far.
4. whether it is possible to see the value of particular pixel in LABVIEW vision development module as we seen only the coordinate position . whether it is applicable to see particular pixel value. Guide us
please, see the below screen shots and provide the solution how effectively decrease or increase the ROI depending on objects position using color pattern match
Attachments:
problem in matching while object moves far.png 515 KBHello,
I have not been using the color pattern matching a lot (especially not in real-time). But since the pattern matching considers only small scale changes, you could try updating the color template every n-th iteration (depending on your setup and requirements). The major problem is the template size, since the color pattern matching tends to take quite a lot of time in learning the template. You would of course need to come up with some idea on how to change the subimage size, where the new template will be learned.
This is the part of coarse (rough) object detection as was suggested by MoviJOHN. For example, if your object is distinctly red, you can extract the green channel from your rgb image and use threshold to roughly find the object and apply the new ROI - template.
So:
1. learn the template,
2. use pattern matching with bounding rectangle (ROI) for the next couple of frames (you would need to experiment here where the detection fails -> how fast can you move the object away so that the detection fails),
3. Before the detection fails -> rough object detection with some padded bounding rectangle (new ROI),
4. Re-learn te template of new ROI and go back to 2.
Again, the biggest issue is the template learning time - if you have a high resolution camera and the template is large, this won't satisfy your real-time application.
You should set up the appropriate illumination first. The resolution is also important, since your object is moved back and forth (but the resolution will have a direct impact on the template learning time).
Best regards,
K
https://decibel.ni.com/content/blogs/kl3m3n
"Kudos: Users may give one another Kudos on the forums for posts that they found particularly helpful or insightful." -
How do I set multiple pattern matching Vi's and make overlapping pattern matches to count as one?
Hello! I'm a student and I'm currently making a project using pattern matching.
My patterns are from chick foot/feet.
I'm created multiple pattern matching VI's to detect all the feet because I find it difficult/impossible to match all the feet with a single pattern/template.
However, when using multiple pattern matching VI's some pattern matches detect the same foot, hence overlapping.
So how can I make the overlaping pattern matches to be counted as one?
Thank you in advanceThank you for replying Sir Zwired1.
I'm still a newbie in using LabVIEW so pardon me if I can't understand fully
The objective of my project is to detect all the feet through pattern matching and count the pattern matches made.
"Keep a 2D array of counts, initialized to zero and the same size as your array of possible locations, and increment the value every time you get a match. If multiple pattern matching attempts result in a match a given location in your count array might be "3" but all you care about is if the number is greater than zero."
I'm sorry, but how do you do this? BTW, I'm using vision assistant. -
Trouble using a pattern match in the GO URL when the value starts with %
Hi guys,
We are trying to use a Go URL as follows:
[http://hostname.com:9704/analytics/saw.dll?Go&Path=/users/administrator/Test/TestReport&Action=Navigate&col1=TestReport.SUBJECT&op1=like&val1="%25D8D8%25"|http://hostname.com:9704/analytics/saw.dll?Go&Path=/users/administrator/Test/TestReport&Action=Navigate&col1=TestReport.SUBJECT&op1=like&val1="%25D8D8%25"]
Basically, we want to send the filter : SUBJECT like '%D8D8%' in the GoURL. However, the report that opens up does not fetch any rows because BI somehow messes up the clause by not recognizing the leading %25 (which is an escaped % character). Instead it resolves the %25D8D8%25 into something like �D8% .
As you can see, the %25 at the end however gets resolved correctly but somehow the one at the beginning gets clubbed with the leading D8 to give �.
Any idea, how to get BI to accept a leading escaped % character when doing a pattern match in the Go URL?I'm heading to the Apple Store in Danbury CT tomorrow to test out a MacBook Pro. I'll happily post what I like and dislike here.
Waiting for a MacBook Pro... Other OS -
Hey all,
I would like to know how can I read a template´s information to know if it is a pattern macthing or a geometric matching template?
In my code, users provide templates and the algorithm must match them using pattern matching or geometric matching depending on the template.
At the moment I am doing it by including a P or a G in the name of the file, but I would like to avoid this and read the information from the file.
Any ideas?
Thanks in advance,
Esteban
Solved!
Go to Solution.Hey Esteban,
you can use the VI "IMAQ Is Vision Info Present 2 VI" to reice the information:
IMAQ Is Vision Info Present 2 VI - NI Vision 2011 for LabVIEW Help - National Instruments
http://zone.ni.com/reference/en-XX/help/370281P-01/imaqvision/imaq_is_vision_info_present_2/
Take a look at the attached VI
Stephan
Attachments:
Determine Pattern type.zip 13 KB -
OBIEE 11G : Remove label (is like pattern match) in the prompt
Hi Experts,
I have Gone through this thread Re: OBIEE 11G : Remove label (is like pattern match) in the prompt and applied JS as mentioed but
It works for the first display of the page but its back as soon as you hit the apply button
can be it be removed permanently? Thanks in AdvanceHi Nagen,
You can try the following:
Create a variable prompt with the column vales that you want to match
Create a filter in the analysis criteria tab on the column, set to pick up the variable, and define the IS LIKE here.
It is effectively doing the same task as the standard prompt approach does, but in a round-a-bout way which doesn't include adding any of Oracle's text in. -
What I want to do is , have two images on image displays and the pass them through the same setup as the pattern matching example to get the number of matches , I have attached what I have done and also given the pattern matching example program as well.
Hope to get answers back soon,
Thanks Alan
Attachments:
screenshot.docx 48 KB
Pattern Matching Example.vi 100 KBHi there!
The example used can be adapted for comparing two images, however the algorithm and coding for finding the differences is more specific to your actual problem. In terms of the loading and displaying of the images, this can be done in the same way.
Once you have some sort of algorithm, then you can automate the learning and matching by simply wiring them in order. (in the example, these are put in case structures as they are waiting on response from the front panel)
I hope that this helps,
Liam A.
National Instruments
Applications Engineer -
Regular Expressions (Pattern/Matcher) --- Help
Hi,
I have an regex i.e. Pattern.compile("([0-9])D([0-9])'?(?:([0-9]+)\")?([NSEW])").{code}
It has to exactly match the input e.g *45D15'34"N*
I need to retrieve the values based on grouping.
Group1 = 45 (degree value)
Group2 = 15 (minutes value)
Group3 = 34 (seconds value) ----> this is a non-capturing group
Group4 = N (directions)
The regex works fine for most of longitude/latitude value but I get a StackOverFlow for some. There is a known bug on this http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=5050507
According to the bug report, they have said that are many different regex that can trigger the stack overflow....even though the length of my input is not as long as the one posted on the bug report.
I was wondering if anyone could suggest a different way of writing the regex above to avoid the stack over flow.
Thank you in advanceHi,
I missed the '+' in my original regex Pattern.compile("([0-9]+)D([0-9]+)'?(?:([0-9]+)\")?([NSEW])"){code}.
I have also tried {code} Pattern.compile("(\\d+)D(\\d+)'?(?:(\\d+)\")?([NSEW])");And, the other 2 expressions as suggested by you.
The problem happens when Durham Lat=35D52N Lon=78D47W value is selected from a Jtree(the values are parsed from a xml file to the tree - the xml file has a bout 800 longitude/latitude elements for different cities in the US). It does not happen for other values and If I increment the degree or min by, then the expression works. I am not sure how else i could re-write this exp.
Below is the snippet of the xml file:
<State name="NORTH CAROLINA">
<City name="Asheville AP" Lat="35D26'N" Lon="82D32'W"/>
<City name="Charlotte AP" Lat="35D13'N" Lon="80D56'W"/>
<City name="Durham" Lat="35D52'N" Lon="78D47'W"/>
<City name="Elizabeth City AP" Lat="36D16'N" Lon="76D11'W"/>
<City name="Fayetteville, Pope AFB" Lat="35D10'N" Lon="79D01'W"/>
<City name="Goldsboro,Seymour-Johnson" Lat="35D20'N" Lon="77D58'W"/>
<City name="Greensboro AP (S)" Lat="36D05'N" Lon="79D57'W"/>
<City name="Greenville" Lat="35D37'N" Lon="77D25'W"/>
<City name="Henderson" Lat="36D22'N" Lon="78D25'W"/>
<City name="Hickory" Lat="35D45'N" Lon="81D23'W"/>
<City name="Jacksonville" Lat="34D50'N" Lon="77D37'W"/>
<City name="Lumberton" Lat="34D37'N" Lon="79D04'W"/>
<City name="New Bern AP" Lat="35D05'N" Lon="77D03'W"/>
<City name="Raleigh/Durham AP (S)" Lat="35D52'N" Lon="78D47'W"/>
<City name="Rocky Mount" Lat="35D58'N" Lon="77D48'W"/>
<City name="Wilmington AP" Lat="34D16'N" Lon="77D55'W"/>
<City name="Winston-Salem AP" Lat="36D08'N" Lon="80D13'W"/>
</State>
public final class GeoLine {
/* Enum for the possible directions of longitude and latitude*/
public enum Direction {
N, S, E, W;
public boolean isLongitude() {
return (this == E || this == W);
public boolean isLatitude() {
return (this == N || this == S);
public Direction getCanonicalDirection() {
if (this == S) {
return Direction.N;
} else if (this == W) {
return Direction.E;
} else {
return this;
private final int degree;
private final int minute;
private final int second;
private final Direction dir;
/* Recognizes longitude and latitude values that has degrees, minutes and seconds i.e. "45D15'34"N
* or "45D1534"N. The single-quotes for the minutes is optional. And, for the moment we do not support seconds
* validation although ilog library returns the longitude/latitude with second when NEs and Sub-networks are
* dragged and dropped on the map.*/
private static final Pattern PATTERN = Pattern.compile("([0-9]+)D([0-9]+)'?(?:([0-9]+)\")?([NSEW])");
public GeoLine(int degree, int minute, Direction dir) {
this(degree, minute, 0, dir);
public GeoLine(int degree, int minute, int second, Direction dir) {
Log.logInfo(getClass().getSimpleName(), "PAU degree: " + degree + " minute: " + minute + " second: " + second + " direction: " + dir);
verifyLongitudeLatitude(degree, dir);
verifyMinute(degree, minute, dir);
this.degree = degree;
this.minute = minute;
this.second = second;
if (this.degree == 0 && this.minute == 0 && this.second == 0) {
this.dir = dir.getCanonicalDirection();
} else {
this.dir = dir;
public Direction getDirection() {
return dir;
public int getMinute() {
return minute;
public int getDegree() {
return degree;
public int getSecond() {
return second;
public static GeoLine parseLine(String location) {
* Matcher class will throw java.lang.NullPointerException if a null location
* is passed, null location validation is not needed.
Matcher m = PATTERN.matcher(location);
if(m.matches()) {
int deg;
int min;
int second;
Direction direction;
deg = Integer.parseInt(m.group(1));
min = Integer.parseInt(m.group(2));
if (m.group(3) == null) {
second = 0;
} else {
second = Integer.parseInt(m.group(3));
direction = Direction.valueOf(m.group(4));
return new GeoLine(deg, min, second, direction);
} else {
throw new IllegalArgumentException("Invalid location value. Expected format XXDXX'XX\"[NSEW] " + location);
private void verifyMinute(int deg, int min, Direction direction) {
/* This validation is to make sure that minute does not exceed 0 if maximum value for latitude == 90
* or longitude == 180 is specified */
int maxDeg = direction.isLatitude() ? 90 : 180;
if(min < 0 || min > 59) {
throw new NumberFormatException("Minutes is out of range. Value should be less than 60: " + min);
if (deg == maxDeg && min > 0) {
throw new NumberFormatException("Degree value " + deg + "D" + direction + " cannot have minute exceeding 0: " + min);
private void verifyLongitudeLatitude(int valDeg, Direction valDir) {
int max = valDir.isLatitude() ? 90 : 180;
if(valDeg < 0 || valDeg > max) {
throw new NumberFormatException("Degree " + valDeg + valDir + " is invalid");
public final boolean isLongitude() {
return dir.isLongitude();
public final boolean isLatitude() {
return dir.isLatitude();
@Override
public final String toString(){
if(minute < 10){
return degree + "D0" + minute + dir;
} else {
return degree + "D" + minute + dir;
@Override
public boolean equals(Object obj) {
if (obj instanceof GeoLine) {
GeoLine other = (GeoLine) obj;
return (this.degree == other.degree && this.minute == other.minute && this.second == other.second && this.dir == other.dir);
return false;
@Override
public int hashCode() {
int result = 17;
result = result * 37 + degree;
result = result * 37 + minute;
result = result * 37 + second;
result = result * 37 + dir.hashCode();
return result;
}Thank you again. -
Mod_security: Access denied with code 405. Pattern match "!(GET|HEAD|POST)
Hi all,
After Cloning facing an issue
mod_security: Access denied with code 405. Pattern match "!(GET|HEAD|POST)"
and not able to get the login prompt
EBS: 12.1.3
DB:11G
Please help as this is urgent.
Regards,
Raj.Hi Hussein/Srini,
My OS details are as follows
Source OS : OE Linux 5X
Target : REHL
DB : 11.2.0.3
In my previous cloning the R12 login URL was not getting redirected to https from http. This backup was given by client last week and I completed the cloning and post cloning procedures without any error, but unable to login as the page is redirecting to https:/hostname:port/OA_HTML/AppsLogin.
I have done the following so far, but the issue is not getting resolved.
1) Generated JAR files using ADADMIN (Force)
2) Compiled JSP
3) Ran autoconfig multiple times without any error in both db and application tiers.
4) DB alert log did not have any error.
5) Executed relink all from APPL_TOP
6) Able to launch http://XXXXXXXXX:XXXX/forms/frmservlet?
Kindly help me out on this
Regards -
who knows how to output some text once labview detects something I want using pattern matching(Vision assistant)?
The text is something like"Yes, this is a coin"
Thanks!I attached a SubVI which I used to place an overlay next to a Pattern, found by a Pattern Match before:
As you can see, you simply pass the image reference and the Array of Matches to the VI along with the String you want to have as an overlay next to the Match.
I also modified your VI a bit, but didn't test it. I created an Array of clusters, each elment containing the template path along with the respective text.
Please note that this is just a hint!
Christian
Attachments:
suggestion.vi 146 KB
Overlay_Txt.vi 24 KB -
How to use AND,OR,NOT condition in Pattern Matching in java
how to use AND,OR,NOT condition in Pattern Matching in java
Please anyone give example..Stop asking these stupid vague questions and do some of your own research.
Start here:
http://www.regular-expressions.info/
http://java.sun.com/j2se/1.5.0/docs/api/java/util/regex/Pattern.html -
Pattern Matching and Vision Builder 6.0
Hi,
When I select a ROI from an image to generate a pattern matching, Builder
saves it as a PNG file.
If I open this pattern in other application (Paint Shop Pro 7) to modified
it and save as a PNG file, after I can't open this file as a pattern into
Builder, because it is considered as a not valid PNG file.
I have tested this case in LabView 6.i and this problem doesn't appear.
Any solution? Thanks.When the template is first saved in Vision Builder, pattern matching information is stored in the header of the PNG file. This information lets LabVIEW and Vision Builder know how the template was learned. Paint Shop Pro does not keep this information in the file whenever it is saved so Vision Builder will not recognize it as a valid pattern matching template.
Jack Arnold
Application Engineer
National Instruments -
Pattern matching problme - not getting desired result.
Hi,
According my program , If 'san' is in 'sangeetha', then it should display "hello".
but I am getting only 'hi'
Why ? any idea?
<%@ page import="java.util.regex.Pattern"%>
<%
if(Pattern.matches("san", "sangeetha"))
out.println("hello");
else
out.println("hi");
%>
Result : Hisangee wrote:
Hi,
According my program , If 'san' is in 'sangeetha', then it should display "hello".No, that isn't what your patten say. You should read about regular expressions and learn how to use them, or switch to String.indexOf or contains.
Kaj
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