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--- ascii_art [2023/03/25 12:21] – [Step 1. Read your image and print its height and width in pixels] frchris
+++ ascii_art [2023/03/25 14:30] – [Step 3. Convert the RGB tuples of your pixels into single brightness numbers] frchris
@@ Line 33: / Line 33: @@
                    """"
 </code>
+This Lab is based on one of  [[https://robertheaton.com/2018/06/12/programming-projects-for-advanced-beginners-ascii-art/|Robert Heaton's Advanced Beginners Projects]].  I have made starter code for Java Students about to take the AP Computer Science A Exam.  You need to know somehting about 2D Arrays and String Objects.
 ==== Step 0. Choose an image ====
@@ Line 126: / Line 129: @@
     try
     {
-      // the line that reads the image file
       this.fileName = fileName;
       image = ImageIO.read(new File(fileName));
@@ Line 159: / Line 161: @@
   private BufferedImage image;
   private String fileName;
+  private int width,height;
+  private int[] rgb; // for 8bit RGB packed in an int array
+  private Color[][] px;
   public Step2(String fileName)
   {
@@ Line 167: / Line 172: @@
       image = ImageIO.read(new File(fileName));
       System.out.println(fileName + " read ");
+      width = image.getWidth();
-      System.out.println("Demensions of " + fileName + ": ");
+      height = image.getHeight();
-      // Print the width and height of the image using a BufferedImage method.
+      System.out.println("Demensions of " + fileName + ": " + width + " by " + height);
+      rgb = image.getRGB(0,0, width, height, null, 0, width);
+      System.out.println(rgb.length);
+      // rgb is a 1D array, with the rows listed one after the other.
+      ///to convert to a 2D array use something like this:
+      // grid (x,y) = rgb[ y*width + x];
+      // Make a new 2D array of color name px, and fill it from the  1D rgb array
+      // for example, px[0][0] = new Color ( rgb[0] );
     }
@@ Line 177: / Line 190: @@
     }
   }
+  public Color[][] getPx() { return px;}
   public static void main(String[] args)
   {
@@ Line 185: / Line 198: @@
 }
 </code>
+ You can see what your new 2D Array of Color looks like with {{ ::step2tester.java |Step2Tester.java}}
 ==== Step 3. Convert the RGB tuples of your pixels into single brightness numbers  ====
+Now that you have a 2D Array of ''Color'', you can use the ''Color'' methods of ''getRed()'', ''getGreen()'', and ''getBlue()'' to assign a single brightness number.   There are many different ways to map RGB values to brightness, and each produces a slightly different style of transformed image. Think of them like Instagram filters. Some examples:
+  - Average: average the R, G and B values - ''(R + G + B) / 3''
+  - Lightness: average the maximum and minimum values out of R, G and B - ''max(R, G, B) + min(R, G, B) / 2''
+  - Luminosity: take a weighted average of the R, G and B values to account for human perception - ''0.21 R + 0.72 G + 0.07 B''
+  - See [[https://stackoverflow.com/questions/596216/formula-to-determine-brightness-of-rgb-color|this stackoverflow thread]] for more detail
 ==== Step 4. Convert brightness numbers to ASCII characters  ====
 ==== Step 5. What if it looks your image looks squashed? ====
-[[https://robertheaton.com/2018/06/12/programming-projects-for-advanced-beginners-ascii-art/|This is from RObert Heaton's Advanced Beginners Projects]]
+[[https://robertheaton.com/2018/06/12/programming-projects-for-advanced-beginners-ascii-art/|This is from Robert Heaton's Advanced Beginners Projects]]