I am working on a method in Java to do some simple edge detection. I want to take the difference of two color intensities one at a pixel and the other at the pixel directly below it. The picture that I am using is being colored black no matter what threshold I put in for the method. I am not sure if my current method is just not computing what I need it to but I am at a loss what i should be tracing to find the issue.
Here is my method thus far:
public void edgeDetection(double threshold)
{
Color white = new Color(1,1,1);
Color black = new Color(0,0,0);
Pixel topPixel = null;
Pixel lowerPixel = null;
double topIntensity;
double lowerIntensity;
for(int y = 0; y < this.getHeight()-1; y++){
for(int x = 0; x < this.getWidth(); x++){
topPixel = this.getPixel(x,y);
lowerPixel = this.getPixel(x,y+1);
topIntensity = (topPixel.getRed() + topPixel.getGreen() + topPixel.getBlue()) / 3;
lowerIntensity = (lowerPixel.getRed() + lowerPixel.getGreen() + lowerPixel.getBlue()) / 3;
if(Math.abs(topIntensity - lowerIntensity) < threshold)
topPixel.setColor(white);
else
topPixel.setColor(black);
}
}
}
new Color(1,1,1) calls the Color(int,int,int) constructor of Color which takes values between 0 and 255. So your Color white is still basically black (well, very dark grey, but not enough to notice).
If you want to use the Color(float,float,float) constructor, you need float literals:
Color white = new Color(1.0f,1.0f,1.0f);
public void edgeDetection(int edgeDist)
{
Pixel leftPixel = null;
Pixel rightPixel = null;
Pixel bottomPixel=null;
Pixel[][] pixels = this.getPixels2D();
Color rightColor = null;
boolean black;
for (int row = 0; row < pixels.length; row++)
{
for (int col = 0;
col < pixels[0].length; col++)
{
black=false;
leftPixel = pixels[row][col];
if (col<pixels[0].length-1)
{
rightPixel = pixels[row][col+1];
rightColor = rightPixel.getColor();
if (leftPixel.colorDistance(rightColor) >
edgeDist)
black=true;
}
if (row<pixels.length-1)
{
bottomPixel =pixels[row+1][col];
if (leftPixel.colorDistance(bottomPixel.getColor())>edgeDist)
black=true;
}
if (black)
leftPixel.setColor(Color.BLACK);
else
leftPixel.setColor(Color.WHITE);
}
}
}
Related
I'm working on a game, nothing serious, just for fun.
I wrote a class 'ImageBuilder' to help creating some images.
Everything works fine, except one thing.
I initialize a variabile like this:
// other stuff
m_tile = new ImageBuilder(TILE_SIZE, TILE_SIZE, BufferedImage.TYPE_INT_RGB).paint(0xff069dee).paintBorder(0xff4c4a4a, 1).build();
// other stuff
Then, in the rendering method, i have:
for (int x = 0; x < 16; x++) {
for (int y = 0; y < 16; y++) {
g.drawImage(m_tile, x * (TILE_SIZE + m_padding.x) + m_margin.x, y * (TILE_SIZE + m_padding.y) + m_margin.y, null);
}
}
Note: m_padding and m_margin are just two Vector2i
This draws on the screen a simple 16x16 table using that image, but the game is almost frozen, i can't get more than like 10 FPS.
I tried to creating the image without that class, by doing this (TILE_SIZE = 32):
m_tile = new BufferedImage(TILE_SIZE, TILE_SIZE, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < TILE_SIZE; x++) {
for (int y = 0; y < TILE_SIZE; y++) {
if (x == 0 || y == 0 || x + 1 == TILE_SIZE || y + 1 == TILE_SIZE)
m_tile.setRGB(x, y, 0x4c4a4a);
else
m_tile.setRGB(x, y, 0x069dee);
}
}
This time, i get 60 FPS.
I can't figure out with is the difference, i used to creating image using 'ImageBuilder' and all is fine, but not this time.
ImageBuilder class:
// Constructor
public ImageBuilder(int width, int height, int imageType) {
this.m_width = width;
this.m_height = height;
this.m_image = new BufferedImage(m_width, m_height, imageType);
this.m_pixels = ((DataBufferInt) m_image.getRaster().getDataBuffer()).getData();
this.m_image_type = imageType;
}
public ImageBuilder paint(int color) {
for (int i = 0; i < m_pixels.length; i++) m_pixels[i] = color;
return this;
}
public ImageBuilder paintBorder(int color, int stroke) {
for (int x = 0; x < m_width; x++) {
for (int y = 0; y < m_height; y++) {
if (x < stroke || y < stroke || x + stroke >= m_width || y + stroke >= m_height) {
m_pixels[x + y * m_width] = color;
}
}
}
return this;
}
public BufferedImage build() {
return m_image;
}
There are other methods, but i don't call them, so i don't think is necessary to write them
What am i doing wrong?
My guess is that the problem is your ImageBuilder accessing the backing data array of the data buffer:
this.m_pixels = ((DataBufferInt) m_image.getRaster().getDataBuffer()).getData();
Doing so, may (will) ruin the chances for this image being hardware accelerated. This is documented behaviour, from the getData() API doc:
Note that calling this method may cause this DataBuffer object to be incompatible with performance optimizations used by some implementations (such as caching an associated image in video memory).
You could probably get around this easily, by using a temporary image in your bilder, and returning a copy of the temp image from the build() method, that has not been "tampered" with.
For best performance, always using a compatible image (as in createCompatibleImage(), mentioned by #VGR in the comments) is a good idea too. This should ensure you have the fastest possible hardware blits.
I'm new to processing. I'm trying to change the color(or another parameter like hue, saturation..) of the pixels around every pixel.
I get nothing changed instead of desired result. Please, help anybody (+
PImage imgg;
void setup() {
size(250,166);
imgg = loadImage("input.jpg");
loadPixels();
image(imgg,0,0);
}
void draw() {
for (int i = 0; i < imgg.width; i++) {
for (int j = 0; j < imgg.height; j++) {
//get the brightness value of the current pixel
int Bright_coeff = int(brightness(pixels[j*imgg.width+i]));
//calculate the area around the current pixel
int Bright_dist = Bright_coeff/10 ;
//area around that pixel will update its color
for (int x = 0; x < imgg.width; x++ ){
for (int y = 0; y < imgg.height; y++){
//check if the distance between iterating pixels and current pixel from above cycle is less than Bright_dist
if ( dist(x, y, i, j)<Bright_dist ){
color qwerty = color(random(1,255),random(1,255),random(1,255)) ;
pixels[y*imgg.width+x] = qwerty;
updatePixels();
}else {
updatePixels();
}
}
}
}
}
}
loadPixels() loads the pixel data of the current display window.
loadPixels has to be done, after the image is drawn to the window by image():
PImage imgg;
void setup() {
size(128,128);
imgg = loadImage("input.jpg");
image(imgg,0,0);
loadPixels();
}
The display is just updated once, after draw() has been executed. updatePixels() set the pixel data for the display window. It is sufficient to do that once at the end of draw():
void draw() {
// [...]
updatePixels();
}
I am attempting to create a new color palette for an image turned to gray scale, and then apply the palette to the gray scale image. I began the method that I wanted to use to apply the palette, but I ran into the error mentioned in the title. I used "java.awt.Color" already in my code, so I am not sure why I am getting the error. Also, as you will see, I placed a color inside the parenthesis.
/**
* This program takes an image, converts it to grayscale, and uses a color palette to create new colors for the image.
*
* #author Dylan Hubbs
* #version 08/02/16
*/
import java.awt.Color ;
class ColorPalette
{
public void grayscaleEffect(Picture pictureObj)
{
int redValue = 0; int greenValue = 0; int blueValue = 0;
Pixel grayscaleTargetPixel = new Pixel(pictureObj, 0,0);
Color grayscalePixelColor = null;
for(int y=0; y < pictureObj.getHeight(); y++)
{
for(int x = 0; x < pictureObj.getWidth(); x++)
{
grayscaleTargetPixel = pictureObj.getPixel(x,y);
grayscalePixelColor = grayscaleTargetPixel.getColor(); //gets the color of the target pixel
grayscalePixelColor = new Color((grayscaleTargetPixel.getRed() + grayscaleTargetPixel.getGreen() + grayscaleTargetPixel.getBlue()) / 3, (grayscaleTargetPixel.getRed() + grayscaleTargetPixel.getGreen() + grayscaleTargetPixel.getBlue()) / 3, (grayscaleTargetPixel.getRed() + grayscaleTargetPixel.getGreen() + grayscaleTargetPixel.getBlue()) / 3);
grayscaleTargetPixel.setColor(grayscalePixelColor); //sets the new color of the target pixel
}//end of the inner for loop
}//end of the outer for loop
pictureObj.explore(); //explore the Picture object which is now the altered image
pictureObj.write("grayscaleWashingtonMonument.jpg"); //write the altered Picture object to a new file
pictureObj.show();
}
public void paletteEffect(Picture pictureObj)
{
int redValue = 0; int greenValue = 0; int blueValue = 0;
Pixel paletteTargetPixel = new Pixel(pictureObj, 0,0);
Color palettePixelColor = null;
Color [] palette = {Color.RED, Color.BLUE, Color.CYAN, Color.GREEN, Color.YELLOW, Color.GRAY, Color.PINK, Color.ORANGE};
for(int y=0; y < pictureObj.getHeight(); y++)
{
for(int x = 0; x < pictureObj.getWidth(); x++)
{
paletteTargetPixel = pictureObj.getPixel(x,y);
palettePixelColor = paletteTargetPixel.getColor();
if(paletteTargetPixel.getRed() >= 1 && paletteTargetPixel.getRed() <= 31)
palettePixelColor.setColor(palette[0]);
else if(paletteTargetPixel.getRed() >= 32 && paletteTargetPixel.getRed() <= 62)
palettePixelColor.setColor(palette[1]);
else if(paletteTargetPixel.retRed() >= 63 && paletteTargetPixel.getRed() <=93)
palettePixelColor.setColor(palette[2]);
}
}
}
}
public class ColorPaletteTester
{
public static void main(String[] args)
{
Picture pictureObj = new Picture("washingtonmonument.jpg"); //creates a new Picture object representing the file in the parameter list
pictureObj.explore();
ColorPalette cp = new ColorPalette();
cp.grayscaleEffect(pictureObj);
cp.paletteEffect(pictureObj);
}
}
So, the error is coming at
palettePixelColor.setColor(palette[0]);
Does anyone know why this would be happening?
palettePixelColor is declared as java.awt.Color, which happens to be an immutable class with no setters. Depending on what Pixel is, it may have such a method.
You are probably trying to do something like
palettePixelColor = palette[0];
or
paletteTargetPixel.setColor(palette[0]);
I have to create a program that manipulates the color pixels of an image to create a look of a sunset in the background. I know to do this I have to increase the amount of the color red in the picture but whenever I program it it results in an error saying:
java.lang.IllegalArgumentException:
Color parameter outside of expected range: Red(in java.awt.Color)
My program looks like this:
import java.awt.*;
public class TrueColors2
{
public static void main(String[] args)
{
Picture pictureObj = new Picture("WashingtonMonument.png");
//picutreObj.explore();
int redValue = 0; int greenValue = 0; int blueValue = 0;
Pixel targetPixel = new Pixel(pictureObj, 0, 0);
Color pixelColor = null;
for(int y = 0; y < pictureObj.getHeight(); y++)
{
for(int x = 0; x < pictureObj.getWidth(); x++)
{
targetPixel = pictureObj.getPixel(x,y);
pixelColor = targetPixel.getColor();
redValue = pixelColor.getRed();
greenValue = pixelColor.getGreen();
blueValue = pixelColor.getBlue();
pixelColor = new Color(redValue, greenValue, blueValue);
pixelColor = new Color(100 + pixelColor.getRed(),
pixelColor.getGreen(),
pixelColor.getBlue());
targetPixel.setColor(pixelColor);
}
}
pictureObj.write("ThirdWashingtonMonument.png");
pictureObj.show();
}
}
Can someone help me figure out what is wrong and help me figure out how to create an effect of a sunset?
Thanks
When you add 100 to your red value, you're probably exceeding the maximum value of 255 at some point. You should consider inspecting the current value of pixelColor.getRed() before you add 100 to it.
I am trying to automatically change the color for a set of icons.
Every icon has a white filled layer and the other part is transparent.
Here is an example: (in this case it's green, just to make it visible)
I tried to do the following:
private static BufferedImage colorImage(BufferedImage image) {
int width = image.getWidth();
int height = image.getHeight();
for (int xx = 0; xx < width; xx++) {
for (int yy = 0; yy < height; yy++) {
Color originalColor = new Color(image.getRGB(xx, yy));
System.out.println(xx + "|" + yy + " color: " + originalColor.toString() + "alpha: "
+ originalColor.getAlpha());
if (originalColor.equals(Color.WHITE) && originalColor.getAlpha() == 255) {
image.setRGB(xx, yy, Color.BLUE.getRGB());
}
}
}
return image;
}
The problem I have is that every pixel I get has the same value:
32|18 color: java.awt.Color[r=255,g=255,b=255]alpha: 255
So my result is just a colored square.
How can I achieve to change the color of the non-transparent parts only? And why is it, that all pixels have even the same alpha value? I guess that's my main problem: That the alpha value isn't read correctly.
Why it doesn't work, I don't know, this will.
This changes all the pixles to blue, maintaining their alpha values...
import java.awt.image.BufferedImage;
import java.awt.image.WritableRaster;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class TestColorReplace {
public static void main(String[] args) {
try {
BufferedImage img = colorImage(ImageIO.read(new File("NWvnS.png")));
ImageIO.write(img, "png", new File("Test.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
}
private static BufferedImage colorImage(BufferedImage image) {
int width = image.getWidth();
int height = image.getHeight();
WritableRaster raster = image.getRaster();
for (int xx = 0; xx < width; xx++) {
for (int yy = 0; yy < height; yy++) {
int[] pixels = raster.getPixel(xx, yy, (int[]) null);
pixels[0] = 0;
pixels[1] = 0;
pixels[2] = 255;
raster.setPixel(xx, yy, pixels);
}
}
return image;
}
}
The problem is, that
Color originalColor = new Color(image.getRGB(xx, yy));
discards all the alpha values. Instead you have to use
Color originalColor = new Color(image.getRGB(xx, yy), true);
to keep alpha values available.
If your bitmap is already set in an ImageView, just do :
imageView.setColorFilter(Color.RED);
to set all non transparent pixels to red.
Since we will always be replacing only the first three bands of the RGB pixel, more effective way to achieve the same without unnecessary allocation of new arrays would be:
private static void colorImageAndPreserveAlpha(BufferedImage img, Color c) {
WritableRaster raster = img.getRaster();
int[] pixel = new int[] {c.getRed(),c.getGreen(),c.getBlue()};
for (int x = 0; x < raster.getWidth(); x++)
for (int y = 0; y < raster.getHeight(); y++)
for (int b = 0; b < pixel.length; b++)
raster.setSample(x,y,b,pixel[b]);
}