Arrays and Images
import javax.imageio.ImageIO;
import java.io.File;
import java.io.IOException;
import java.awt.image.BufferedImage;
public class ImageIOTest {
public static void main( String[] args ){
BufferedImage img = null; // buffer type
try {
// Name of file and directories
String name = "MonaLisa";
String in = "images/";
String out = "images/tmp/";
// Either use URL or File for reading image using ImageIO
File imageFile = new File(in + name + ".png");
img = ImageIO.read(imageFile); // set buffer of image data
// ImageIO Image write to gif in Java
// Documentation https://docs.oracle.com/javase/tutorial/2d/images/index.html
ImageIO.write(img, "gif", new File(out + name + ".gif") ); // write buffer to gif
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Success");
}
}
ImageIOTest.main(null);
Image Scaling and ASCII Conversion
In this example we print out a row of text for each row in the image. However, it seems as if the image is too tall. To address this problem, try to output a single character per block of pixels. In particular, average the grayscale values in a rectangular block that’s twice as tall as it is wide, and print out a single character for this block.
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.awt.Image;
import java.awt.Graphics2D;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.ImageReader;
import javax.imageio.ImageTypeSpecifier;
public class Pics {
private final String inDir = "images/"; // location of images
private final String outDir = "images/tmp/"; // location of created files
private String inFile;
private String resizedFile;
private String asciiFile;
private String ext; // extension of file
private long bytes;
private int width;
private int height;
// Constructor obtains attributes of picture
public Pics(String name, String ext) {
this.ext = ext;
this.inFile = this.inDir + name + "." + ext;
this.resizedFile = this.outDir + name + "." + ext;
this.asciiFile = this.outDir + name + ".txt";
this.setStats();
}
// An image contains metadata, namely size, width, and height
public void setStats() {
BufferedImage img;
try {
Path path = Paths.get(this.inFile);
this.bytes = Files.size(path);
img = ImageIO.read(new File(this.inFile));
this.width = img.getWidth();
this.height = img.getHeight();
} catch (IOException e) {
}
}
// Console print of data
public void printStats(String msg) {
System.out.println(msg + ": " + this.bytes + " " + this.width + "x" + this.height + " " + this.inFile);
}
// Convert scaled image into buffered image
public static BufferedImage convertToBufferedImage(Image img) {
// Create a buffered image with transparency
BufferedImage bi = new BufferedImage(
img.getWidth(null), img.getHeight(null),
BufferedImage.TYPE_INT_ARGB);
// magic?
Graphics2D graphics2D = bi.createGraphics();
graphics2D.drawImage(img, 0, 0, null);
graphics2D.dispose();
return bi;
}
// Scale or reduce to "scale" percentage provided
public void resize(int scale) {
BufferedImage img = null;
Image resizedImg = null;
int width = (int) (this.width * (scale/100.0) + 0.5);
int height = (int) (this.height * (scale/100.0) + 0.5);
try {
// read an image to BufferedImage for processing
img = ImageIO.read(new File(this.inFile)); // set buffer of image data
// create a new BufferedImage for drawing
resizedImg = img.getScaledInstance(width, height, Image.SCALE_SMOOTH);
} catch (IOException e) {
return;
}
try {
ImageIO.write(convertToBufferedImage(resizedImg), this.ext, new File(resizedFile));
} catch (IOException e) {
return;
}
this.inFile = this.resizedFile; // use scaled file vs original file in Class
this.setStats();
}
// convert every pixel to an ascii character (ratio does not seem correct)
public void convertToAscii() {
BufferedImage img = null;
PrintWriter asciiPrt = null;
FileWriter asciiWrt = null;
try {
File file = new File(this.asciiFile);
Files.deleteIfExists(file.toPath());
} catch (IOException e) {
System.out.println("Delete File error: " + e);
}
try {
asciiPrt = new PrintWriter(asciiWrt = new FileWriter(this.asciiFile, true));
} catch (IOException e) {
System.out.println("ASCII out file create error: " + e);
}
try {
img = ImageIO.read(new File(this.inFile));
} catch (IOException e) {
}
for (int i = 0; i < img.getHeight(); i++) {
for (int j = 0; j < img.getWidth(); j++) {
Color col = new Color(img.getRGB(j, i));
double pixVal = (((col.getRed() * 0.30) + (col.getBlue() * 0.59) + (col
.getGreen() * 0.11)));
try {
asciiPrt.print(asciiChar(pixVal));
asciiPrt.flush();
asciiWrt.flush();
} catch (Exception ex) {
}
}
try {
asciiPrt.println("");
asciiPrt.flush();
asciiWrt.flush();
} catch (Exception ex) {
}
}
}
// conversion table, there may be better out there ie https://www.billmongan.com/Ursinus-CS173-Fall2020/Labs/ASCIIArt
public String asciiChar(double g) {
String str = " ";
if (g >= 240) {
str = " ";
} else if (g >= 210) {
str = ".";
} else if (g >= 190) {
str = "*";
} else if (g >= 170) {
str = "+";
} else if (g >= 120) {
str = "^";
} else if (g >= 110) {
str = "&";
} else if (g >= 80) {
str = "8";
} else if (g >= 60) {
str = "#";
} else {
str = "@";
}
return str;
}
// tester/driver
public static void main(String[] args) throws IOException {
Pics monaLisa = new Pics("MonaLisa", "png");
monaLisa.printStats("Original");
monaLisa.resize(33);
monaLisa.printStats("Scaled");
monaLisa.convertToAscii();
Pics pumpkin = new Pics("pumpkin", "png");
pumpkin.printStats("Original");
pumpkin.resize(33);
pumpkin.printStats("Scaled");
pumpkin.convertToAscii();
Pics Autumn = new Pics("Autumn", "png");
Autumn.printStats("Original");
Autumn.resize(33);
Autumn.printStats("Scaled");
Autumn.convertToAscii();
}
}
Pics.main(null);
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.awt.Image;
import java.awt.Graphics2D;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.ImageReader;
import javax.imageio.ImageTypeSpecifier;
abstract class ImageBlueprint {
protected final String inDir = "images/"; // location of images
protected final String outDir = "images/tmp/"; // location of created files
protected String inFile;
protected String resizedFile;
protected String colorFile;
protected String ext; // extension of file
protected long bytes;
protected int width;
protected int height;
// get attributes of picture
public ImageBlueprint(String name, String ext) {
this.ext = ext;
this.inFile = this.inDir + name + "." + ext;
this.resizedFile = this.outDir + name + "." + ext;
this.colorFile = this.outDir + name + "New" + ".png";
this.setStats();
}
public ImageBlueprint(String image) {
this(image, "png");
}
// An image contains metadata, namely size, width, and height
public void setStats() {
BufferedImage img;
try {
Path path = Paths.get(this.inFile);
this.bytes = Files.size(path);
img = ImageIO.read(new File(this.inFile));
this.width = img.getWidth();
this.height = img.getHeight();
} catch (IOException e) {
}
}
// Scale or reduce to "scale" percentage provided
public void resize(int scale) {
BufferedImage img = null;
Image resizedImg = null;
int width = (int) (this.width * (scale/100.0) + 0.5);
int height = (int) (this.height * (scale/100.0) + 0.5);
try {
// read an image to BufferedImage for processing
img = ImageIO.read(new File(this.inFile)); // set buffer of image data
// create a new BufferedImage for drawing
resizedImg = img.getScaledInstance(width, height, Image.SCALE_SMOOTH);
} catch (IOException e) {
return;
}
//ImageIO.write(convertToBufferedImage(resizedImg), this.ext, new File(resizedFile));
this.inFile = this.resizedFile; // use scaled file vs original file in Class
this.setStats();
}
// Will be used later
protected abstract void conversion();
}
public class RedConversion extends ImageBlueprint {
public RedConversion(String name, String ext) {
super(name, ext);
this.colorFile = this.outDir + name + "Red" + ".png";
}
public RedConversion(String name) {
super(name);
this.colorFile = this.outDir + name + "Red" + ".png";
}
@Override
protected void conversion() {
BufferedImage img = null;
PrintWriter colorPrt = null;
FileWriter colorWrt = null;
// Just deletes file if already exists in tmp
try {
File file = new File(this.colorFile);
Files.deleteIfExists(file.toPath());
} catch (IOException e) {
System.out.println("Delete File error: " + e);
}
// try {
// colorPrt = new PrintWriter(colorWrt = new FileWriter(this.colorFile, true));
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
try {
img = ImageIO.read(new File(this.inFile));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0; i < this.height; i++) {
for (int j = 0; j < this.width; j++) {
Color col = new Color(img.getRGB(j, i));
int rgb = new Color(col.getRed(), 0, 0).getRGB();
img.setRGB(j, i, rgb);
}
}
try {
ImageIO.write(img, "png", new File(this.colorFile) );
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
RedConversion autumn = new RedConversion("autumn", "png");
autumn.conversion();
}
}
RedConversion.main(null);
public class GreenConversion extends ImageBlueprint {
public GreenConversion(String name, String ext) {
super(name, ext);
this.colorFile = this.outDir + name + "Green" + ".png";
}
public GreenConversion(String name) {
super(name);
this.colorFile = this.outDir + name + "Green" + ".png";
}
@Override
protected void conversion() {
BufferedImage img = null;
PrintWriter colorPrt = null;
FileWriter colorWrt = null;
// Just deletes file if already exists in tmp
try {
File file = new File(this.colorFile);
Files.deleteIfExists(file.toPath());
} catch (IOException e) {
System.out.println("Delete File error: " + e);
}
// try {
// colorPrt = new PrintWriter(colorWrt = new FileWriter(this.colorFile, true));
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
try {
img = ImageIO.read(new File(this.inFile));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0; i < this.height; i++) {
for (int j = 0; j < this.width; j++) {
Color col = new Color(img.getRGB(j, i));
int rgb = new Color(0, col.getGreen(), 0).getRGB();
img.setRGB(j, i, rgb);
}
}
try {
ImageIO.write(img, "png", new File(this.colorFile) );
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
GreenConversion Autumn = new GreenConversion("Autumn", "png");
Autumn.conversion();
}
}
GreenConversion.main(null);
public class BlueConversion extends ImageBlueprint {
public BlueConversion(String name, String ext) {
super(name, ext);
this.colorFile = this.outDir + name + "Blue" + ".png";
}
public BlueConversion(String name) {
super(name);
this.colorFile = this.outDir + name + "Blue" + ".png";
}
@Override
protected void conversion() {
BufferedImage img = null;
PrintWriter colorPrt = null;
FileWriter colorWrt = null;
// Just deletes file if already exists in tmp
try {
File file = new File(this.colorFile);
Files.deleteIfExists(file.toPath());
} catch (IOException e) {
System.out.println("Delete File error: " + e);
}
// try {
// colorPrt = new PrintWriter(colorWrt = new FileWriter(this.colorFile, true));
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
try {
img = ImageIO.read(new File(this.inFile));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0; i < this.height; i++) {
for (int j = 0; j < this.width; j++) {
Color col = new Color(img.getRGB(j, i));
int rgb = new Color(0, 0, col.getBlue()).getRGB();
img.setRGB(j, i, rgb);
}
}
try {
ImageIO.write(img, "png", new File(this.colorFile) );
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
BlueConversion Autumn = new BlueConversion("Autumn", "png");
Autumn.conversion();
}
}
BlueConversion.main(null);
public class GrayConversion extends ImageBlueprint {
public GrayConversion(String name, String ext) {
super(name, ext);
this.colorFile = this.outDir + name + "Gray" + ".png";
}
public GrayConversion(String name) {
super(name);
this.colorFile = this.outDir + name + "Gray" + ".png";
}
@Override
protected void conversion() {
BufferedImage img = null;
PrintWriter colorPrt = null;
FileWriter colorWrt = null;
// Just deletes file if already exists in tmp
try {
File file = new File(this.colorFile);
Files.deleteIfExists(file.toPath());
} catch (IOException e) {
System.out.println("Delete File error: " + e);
}
// try {
// colorPrt = new PrintWriter(colorWrt = new FileWriter(this.colorFile, true));
// } catch (IOException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
// }
try {
img = ImageIO.read(new File(this.inFile));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0; i < this.height; i++){
for (int j = 0; j < this.width; j++){
Color col = new Color(img.getRGB(j,i));
int rgb = new Color(((col.getRed()+ col.getGreen()+ col.getBlue())/3), ((col.getRed()+ col.getGreen()+ col.getBlue())/3), ((col.getRed()+ col.getGreen()+ col.getBlue())/3)).getRGB();
img.setRGB(j, i, rgb);
}
}
try {
ImageIO.write(img, "png", new File(this.colorFile) );
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static void main(String[] args) {
GrayConversion Autumn = new GrayConversion("Autumn", "png");
Autumn.conversion();
}
}
GrayConversion.main(null);
ASCII
We are going to convert images to ASCII characters. The existing problem with the current method is that it stretched the image out, hurting the appeal. The best solution is to take 4 rows and 2 columns of pixels and convert them into a single ASCII character.
The finished result still looks horrible.
public class ASCIIConversion extends ImageBlueprint {
public ASCIIConversion(String name, String ext) {
super(name, ext);
this.colorFile = this.outDir + name + "ASCII" + ".txt";
}
public ASCIIConversion(String name) {
super(name);
this.colorFile = this.outDir + name + "ASCII" + ".txt";
}
@Override
protected void conversion() {
// Controls how big chunks are taken for ASCII characters
final int XLENGTH = 1;
final int YLENGTH = 2;
BufferedImage img = null;
PrintWriter asciiPrt = null;
FileWriter asciiWrt = null;
Color col = null;
try {
File file = new File(this.colorFile);
Files.deleteIfExists(file.toPath());
} catch (IOException e) {
System.out.println("Delete File error: " + e);
}
try {
asciiPrt = new PrintWriter(asciiWrt = new FileWriter(this.colorFile, true));
} catch (IOException e) {
System.out.println("ASCII out file create error: " + e);
}
try {
img = ImageIO.read(new File(this.inFile));
} catch (IOException e) {
}
for (int i = 0; i < img.getHeight(); i += 4) {
for (int j = 0; j < img.getWidth(); j += 2) {
// colorSum stores total sum of RGB values, counter keeps track of how many are being counted
// colorSum/counter = average
// average is taken to get ASCII character
double colorSum = 0;
int counter = 0;
for (int k = 0; k < XLENGTH; k++) {
for (int l = 0; l < YLENGTH; l++) {
if (k < img.getWidth() && l < img.getHeight()) {
counter++;
col = new Color(img.getRGB(j + k, i + l));
colorSum += (((col.getRed() * 0.30) + (col.getBlue() * 0.59) + (col
.getGreen() * 0.11)));
}
}
}
double average = colorSum / counter;
try {
asciiPrt.print(asciiChar(average));
asciiPrt.flush();
asciiWrt.flush();
} catch (Exception ex) {
}
}
try {
asciiPrt.println("");
asciiPrt.flush();
asciiWrt.flush();
} catch (Exception ex) {
}
}
}
public String asciiChar(double g) {
String str = " ";
if (g >= 240) {
str = " ";
} else if (g >= 210) {
str = ".";
} else if (g >= 190) {
str = "*";
} else if (g >= 170) {
str = "+";
} else if (g >= 120) {
str = "^";
} else if (g >= 110) {
str = "&";
} else if (g >= 80) {
str = "8";
} else if (g >= 60) {
str = "#";
} else {
str = "@";
}
return str;
}
public static void main(String[] args) {
ASCIIConversion Autumn = new ASCIIConversion("Autumn", "png");
Autumn.conversion();
}
}
ASCIIConversion.main(null);
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.awt.Image;
import java.awt.Graphics2D;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import javax.imageio.stream.ImageOutputStream;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.ImageReader;
import javax.imageio.ImageTypeSpecifier;
public class Pics {
private final String inDir = "images/"; // location of images
private final String outDir = "images/tmp/"; // location of created files
private String inFile;
private String resizedFile;
private String asciiFile;
private String ext; // extension of file
private long bytes;
private int width;
private int height;
// Constructor obtains attributes of picture
public Pics(String name, String ext) {
this.ext = ext;
this.inFile = this.inDir + name + "." + ext;
this.resizedFile = this.outDir + name + "." + ext;
this.asciiFile = this.outDir + name + ".txt";
this.setStats();
}
// An image contains metadata, namely size, width, and height
public void setStats() {
BufferedImage img;
try {
Path path = Paths.get(this.inFile);
this.bytes = Files.size(path);
img = ImageIO.read(new File(this.inFile));
this.width = img.getWidth();
this.height = img.getHeight();
} catch (IOException e) {
}
}
// Console print of data
public void printStats(String msg) {
System.out.println(msg + ": " + this.bytes + " " + this.width + "x" + this.height + " " + this.inFile);
}
// Convert scaled image into buffered image
public static BufferedImage convertToBufferedImage(Image img) {
// Create a buffered image with transparency
BufferedImage bi = new BufferedImage(
img.getWidth(null), img.getHeight(null),
BufferedImage.TYPE_INT_ARGB);
// magic?
Graphics2D graphics2D = bi.createGraphics();
graphics2D.drawImage(img, 0, 0, null);
graphics2D.dispose();
return bi;
}
// Scale or reduce to "scale" percentage provided
public void resize(int scale) {
BufferedImage img = null;
Image resizedImg = null;
int width = (int) (this.width * (scale/100.0) + 0.5);
int height = (int) (this.height * (scale/100.0) + 0.5);
try {
// read an image to BufferedImage for processing
img = ImageIO.read(new File(this.inFile)); // set buffer of image data
// create a new BufferedImage for drawing
resizedImg = img.getScaledInstance(width, height, Image.SCALE_SMOOTH);
} catch (IOException e) {
return;
}
try {
ImageIO.write(convertToBufferedImage(resizedImg), this.ext, new File(resizedFile));
} catch (IOException e) {
return;
}
this.inFile = this.resizedFile; // use scaled file vs original file in Class
this.setStats();
}
// convert every pixel to an ascii character (ratio does not seem correct)
public void convertToAscii() {
BufferedImage img = null;
PrintWriter asciiPrt = null;
FileWriter asciiWrt = null;
try {
File file = new File(this.asciiFile);
Files.deleteIfExists(file.toPath());
} catch (IOException e) {
System.out.println("Delete File error: " + e);
}
try {
asciiPrt = new PrintWriter(asciiWrt = new FileWriter(this.asciiFile, true));
} catch (IOException e) {
System.out.println("ASCII out file create error: " + e);
}
try {
img = ImageIO.read(new File(this.inFile));
} catch (IOException e) {
}
for (int i = 0; i < img.getHeight(); i+=2) {
for (int j = 0; j < img.getWidth(); j+=1) {
Color col = new Color(img.getRGB(j, i));
double pixVal = (((col.getRed() * 0.30) + (col.getBlue() * 0.59) + (col
.getGreen() * 0.11)));
try {
asciiPrt.print(asciiChar(pixVal));
asciiPrt.flush();
asciiWrt.flush();
} catch (Exception ex) {
}
}
try {
asciiPrt.println("");
asciiPrt.flush();
asciiWrt.flush();
} catch (Exception ex) {
}
}
}
// conversion table, there may be better out there ie https://www.billmongan.com/Ursinus-CS173-Fall2020/Labs/ASCIIArt
public String asciiChar(double g) {
String str = " ";
if (g >= 240) {
str = " ";
} else if (g >= 210) {
str = ".";
} else if (g >= 190) {
str = "*";
} else if (g >= 170) {
str = "+";
} else if (g >= 120) {
str = "^";
} else if (g >= 110) {
str = "&";
} else if (g >= 80) {
str = "8";
} else if (g >= 60) {
str = "#";
} else {
str = "@";
}
return str;
}
// tester/driver
public static void main(String[] args) throws IOException {
Pics monaLisa = new Pics("MonaLisa", "png");
monaLisa.printStats("Original");
monaLisa.resize(33);
monaLisa.printStats("Scaled");
monaLisa.convertToAscii();
Pics pumpkin = new Pics("pumpkin", "png");
pumpkin.printStats("Original");
pumpkin.resize(33);
pumpkin.printStats("Scaled");
pumpkin.convertToAscii();
Pics autumn = new Pics("autumn", "png");
autumn.printStats("Original");
autumn.resize(33);
autumn.printStats("Scaled");
autumn.convertToAscii();
}
}
Pics.main(null);