I have a problem that is associated with Fast Fourier Transform of an image. I've made an application with some filters for an images. It's a program with JLabels for displaying images before and after filtration and JButtons for filters. So, my problem is with FFT for an image, i've seen examples for that transformation, but i really don't know how to use that in my program.
I'm trying to implement fast fourier transformation using recursion, at line 28 I'm getting null pointer exception.The algorithm is suppose to break the array in two parts computes real' and imaginary' at the end to each call stores the value in each call. After which further divide the array in two parts and compute.
As part of a homework assignment in my 1st Java Class, I am creating my own Circular Generic LinkedList and Array class. My class uses the Queue Interface Extends Iterable but I am creating my own methods to work with. For the most part, I believe I have been successful in creating the class aside from one method. That method is the Iterator<E> iterator().
/** * Return a fail-fast iterator, which throw a java.util.ConcurrentModificationException * if the client modifies the collection (via enqueue(...) or dequeue()) during iteration. */ @Override public Iterator<E> iterator() {
I don't understand how an iterator, let alone a "fail-fast" iterator ties into my project. I've spent hours reading up on a way to imploy my own generic fail-fast iterator but to no avail.
I feel like I could come up with some workable code if I knew what the point is to useing a user-defined, non Java Library iterator is to do.
As well, does throwing a ConcurrentModificationException require a try and catch block?
I'm currently working on a RSA Encryption using Fast Exponential technique. As the numbers I'm working with will be very huge, I am forced to use BigInteger.
As this is the first time I'm using Big Integer, I encountered quite a number of issues. I'll try my best to explain the errors I'm facing:
1. I had done this step: BigInteger d;
So I'm currently trying to get d = 0;
However, I keep getting an error required: BigInteger, found int.
When I changed it to d = new BigInteger(0) , I get this error:
java:19: error: constructor BigInteger in class BigInteger cannot be applied to given types;
d = new BigInteger(0); ^ required: no arguments found: int reason: actual and formal argument lists differ in length
Part of Code:
public class BigFastExponential { BigInteger e; // public exponenet: all has this BigInteger d; // private key: only key owner has this BigInteger n; // public modulus: all has this
/** * Create a LongRSA object for a public key holder, with just e and n. */ public BigFastExponential(BigInteger public_e, BigInteger public_n)
Exception in thread "main" java.lang.NullPointerException at javax.swing.ImageIcon.<init>(ImageIcon.java:205) at GUI.<init>(GUI.java:26) at Apples.main(Apples.java:7)
i think the problem is to do with my images not being recognised. I put them in my source in User>...>workspace>src which is correct as far as i know. From what i know the images should show up if i look at my src file in eclipse but they dont. I tried changing the file type from .png to .jpg but it makes no difference.
I'm experimenting with AffineTransform, Basically I've created just a simple test GUI to see how the code works and all that. Anyway, there are two buttons which turn an image left and right and a third button with moves the image to the right (East). When you first run the program the image is facing down (South). Now to turn left or right I'm using an Affine Transform and the rotate method. That works fine. The issue is when I move the image to the right, it ignore whatever rotation I previously I made (from turn left and right buttons). Therefore when I click to move the image, it faces down again even if it was facing left or up or right before I moved it. It will always be facing down. How do I get it to keep the rotation and just move? Btw I'm using the setTranslate method to move the image.
Below is my code.
Images.java import java.awt.image.BufferedImage; import java.io.IOException; import java.net.URL; import javax.imageio.ImageIO; public class Images { static BufferedImage Icon, Rover;
I am working on a UI in JavaFX and create several instances of a custom control class. The control consists of a Pane which wraps several other containers, one of which contains a Circle shape.
At one point, I instance this control and access the Circle shape directly. I transform it's center coordinates (which are always {0.0, 0.0} ) to Scene coordinates. The problem is, the transformation always yields coordinates that correspond to the upper left corner of the control's root pane.
In other words, it's as if the Circle is positioned at the upper left corner of the custom control (when, in fact, it's positioned near the lower right corner).
I have other instanced controls already in the scene, and they do not have this issue - converting the Circle's coordinates to scene coordinates works as it should.
It seems obvious that I'm accessing the Circle too soon - that perhaps the scene graph hasn't been fully traversed for the control and the Circle's position within the control's hierarchy hasn't been updated. I've verified that my attempt to access the Circle's center coordinates occurs after the control's initialize() method is executed, so how to ensure the control's scene graph has been fully updated before I try to manipulate the control...
I was trying to write a program that will accept values and transform the scores to grade. Like 70 and above will be given A from 60 to 69 is B, from 50 to 59 is C, from 40 to 49 is D and below 40 is F. I have defined the variables, for the textfield, am confused on how make this hapen on just a click of the comand botton.
7.Front desk search the vacant room to be assigned to the guest
Functions:
1. View all rooms 2. Add Customer to a room 3. Display available room 4. Delete customer from a room 5. Find room from customer name 6. Exit
Files:
One file use to store room info. (to be retrieved by program)
One file use to store rate info. (to be retrieve by program)
One file use to store the booking details (to be created and write by the program).
Currently I have write a program but only compiling and display the output to the console. How to modify my code below to be able to save to the .txt file
Here is the code:
import java.util.*; import java.io.*; class Customer { private String name; private int room; public void setName(String name) { this.name=name;
Given a Date such as this sampleDate (120, 08, 02), does SimpleDateFormat transform this given sampleDate using (sampleDate.get(Calendar.DATE)) ?
Issue is that without the SimpleDateFormat the days are outputting correctly but starting with 1,2,3,4 etc and when I apply the SimpleDateFormat to the above Date I only get 01,01,01 etc...
I need to transformation the txt files into xml files, but each row txt files don't have same elements, for example the first book is composite one author
I just finished a tutorial on youtube that covers the basic java, and now i want to try and make a game / program thing, only problem is that i have never worked with graphics before (i have tried to make ovals, rectangles, and other things with the paint method tho )
I know how to make a jframe and a jpanel, and i feel like i can make a simple "game" (not a complicated one, just a simple one with a guy walking around on the screen) in fact i have already make a such game, where you are a oval walking around on the screen, so thats not really my problem.
My problem is that i want to draw an image on the screen that can walk around instead of the oval, but how to do that. I have made a new project and set up the jframe and jpanel, and my code looks like this:
(main)
import javax.swing.JFrame; public class main_class { public static void main(String[] args){ JFrame f = new JFrame(); f.setTitle("title"); f.setVisible(true); f.setSize(800,600);
[code]...
but once again, i get a blank jframe with no image and no "test" string . How i can display images on the screen?
I have code to convert tiff image to PNG image.I want to scale my PNG image to 800X800 without losing quality.I use the below code but seems doesn't work.Its not resizing the image to specific height and width.
Java Code:
SeekableStream seekableStream = new FileSeekableStream(file); ImageDecoder imageDecoder = ImageCodec.createImageDecoder( Constants.TIFF, seekableStream, null); RenderedImage renderedImage[] = new RenderedImage[imageDecoder .getNumPages()]; for (int i = 0; i < imageDecoder.getNumPages(); i++) {
I usually code in PHP, C++ and ActionScript.I'm trying to follow an example of how to add images to a full screen application. What he does is that he adds a JPG background image, and then 4 PNG images. I tried to do it like I always do, by writing the code by myself looking at the book. It didn't work. I searched for errors in the code, changed some things, tried different things, but it didn't work. Then I tried to use his own code, that I downloaded from his website. That didn't work either.. I tried to find another way to add an image, and I can't seem to figure out a way to implement images in any other way into this class that's written in this book.. My Java programming level isn't just high enough.
Here's the code for the file where the images load, downloaded from the authors website (I've modified the brackets and some spaces so that it becomes easier to read):
Java Code:
import java.awt.*; import javax.swing.ImageIcon; import javax.swing.JFrame; public class ImageTest extends JFrame { public static void main(String[] args) { DisplayMode displayMode;
I am currently working on Java software which resize jpeg images and change DPI also. For JPEG images having app0JFIF node it works fine and the images new DPI is reflected in Photoshop. But if app0JFIF node not exist, I am trying to create a new one and set the DPI value there. Everything is going proper but if I open these images in photoshop it does not reflect new DPI but the size changes.
I'm just wondering whether it is possible to use images as a button in Java. I have two images that I want to use to create a rollover effect, is this possible? And then I would like to reset my java program when the button is clicked, is this also possible?
I have been trying my hand at making 2d top down view games and have found myself repeatedly using the same code so i created a file with all the functions so when it is down i just import the jar and dont have to keep rewriting functions. I have trouble because the background is loaded on the screen and i dont know why as i didn't tell it to load. In fact I set the panels visiblity to false. Both of my classes are in the same package. Why I still get the Image.
Walking Turtle Java Code: import javax.swing.*; import java.awt.event.*; public class turtleWalker extends JFrame{ public static void main(String[] args){ JFrame frame = new JFrame("Walking Turtle");
I am still playing around with decks of cards, and am now trying to implement some visualizations using Applets.
Here is how I enter my deck of cards into an array list: this works just fine:
String[] Suits = new String[]{"S","H","D","C"}; String[] Values = new String[]{"A","2","3","4","5","6","7","8","9","10","J","Q","K"}; ArrayList<String> deck = new ArrayList<String>(); for(String suit : Suits) { for(String value : Values) { deck.add(suit+"_"+value); } }
The end result of this is an array 'deck' which contains a string representing each of the 52 playing cards. Great.
Now I would also like to use some pictures for future implementations I am working on. I have 52 images (.png, though I doubt it matters) stored in the right place. They are named as "H_5.png", and "S_A.png", for example, just as I named the cards in the previous array. I would like to do something as follows
ArrayList<Image> deckpic = new ArrayList<Image>(); for(String suit : Suits) { for(String value : Values) { deckpic.add(getImage(suit+"_"+value+".png")); } }
Now of course this doesn't work. The line
suit+"_"+value+".png"
is a string, not the name of a file. How I have previously loaded images is to use something like this:
the_pic = getImage("picture_of_pony.jpg");
but of course I can't use the quotations in my card loop, since I want "suit" and "value" to range and not just be the strings suit and value.
I am trying to use images as my backgrounds for my JPanel.the problem is when I run the program the images don't show at first.T hey start to show after I have switched to another panel and then switch back. Here are my codes
I read many posts online and watched tutorials on YouTube. I can't seem to get this work. Notice I am not using any drawing/graphics capabilities - I'd like to keep it this way as we have not gotten that far yet in my studies.The image is in a source folder titled Images under/in my project.
Java Code:
private JPanel jpImage = new JPanel(); private JLabel lblImage; private ImageIcon image; private Image img; // All those above defined prior to method // Within method (relevant to code above) ...
import javax.swing.*; import java.awt.*; import java.awt.event.*; public class sample{ public static void main(String args[]){ JFrame frame = new JFrame(); frame.setSize(300,300);
[code]....
To limit the amount of drawing done i want unmoving objects to be painted once. So i set a boolean. When it first load the boolean is false so it draws then after first draw i never want it to draw the objects agian but leave them on the screen. Now in this if you run it you get a black screen.
If you didnt have the "getContentPane().setBackground(Color.black)" it would work fine and show a blue brick. Is there something I don't understand about the setBackgound Function that makes it automatically redone even when not called? and if so how do i overwrite this?
I need to make android app for image comparison. It has to show two images and user will choose which image he prefer by using radio button . After clicking one radio button app should save the result of a duel and show another pair of images.
If there is N images it will be ((n*n)-n)/2 duels. I think of something like this - [URL] .... but instead of 2 radio buttons it will be 9 - 4 for each image (depending on preference) and 1 neutral button(no preference).
How to achieve that. I started using java and eclipse recently only so it is all new to me. I made an activity in xml so far and I tried to make class for changing imageview 1 and 2 assuming that all images will be named a1,a2,a3 .