More image array tests, more docs

src/edu/macalester/graphics/Image.java

@@ -127,7 +127,7 @@ public Image(double x, double y, String path) {
      * (see {@link PixelFormat}.)
      * <p>
      * For example, the array <code>{ 1, 0.5f, 0, 0, 0, 0.5f }</code> with the RGB pixel format
-     * specifies one orange pixel (R=1, G=0.5, B=0), then one dark blue pixel (R=0, G=0, B=0.5).
+     * specifies one orange pixel (R=100%, G=50%, B=0%), then one dark blue pixel (R=0%, G=0%, B=50%).
      *
      * @param width Image width in pixels
      * @param height Image height in pixels
@@ -146,7 +146,7 @@ public Image(int width, int height, float[] pixels, PixelFormat format) {
      * (see {@link PixelFormat}.)
      * <p>
      * For example, the array <code>{ -1, 127, 0, 0, 0, 127 }</code> with the RGB pixel format
-     * specifies one orange pixel (R=1, G=0.5, B=0), then one dark blue pixel (R=0, G=0, B=0.5).
+     * specifies one orange pixel (R=100%, G=50%, B=0%), then one dark blue pixel (R=0%, G=0%, B=50%).
      *
      * @param width Image width in pixels
      * @param height Image height in pixels
@@ -273,10 +273,32 @@ private double getScaleToFit() {
                 maxHeight / getImageHeight()));
     }
 
+    /**
+     * Returns the pixels in this image as an array of bytes, one byte per color channel per pixel,
+     * interleaved in the order specified by <code>format</code>. Zero is minimum intensity, and
+     * 255 (or -1, since bytes are signed) is full intensity.
+     * <p>
+     * Note that when requesting a grayscale image, this method averages the color channels, which
+     * produces results that correspond poorly to perceived brightness.
+     *
+     * @see #Image(int,int,byte[],PixelFormat)
+     * @see #toFloatArray(PixelFormat) 
+     */
     public byte[] toByteArray(PixelFormat format) {
         return format.makeByteArray(img);
     }
 
+    /**
+     * Returns the pixels in this image as an array of floats, one number per color channel per
+     * pixel, interleaved in the order specified by <code>format</code>. Zero is minimum intensity,
+     * and 1 is full intensity.
+     * <p>
+     * Note that when requesting a grayscale image, this method averages the color channels, which
+     * produces results that correspond poorly to perceived brightness.
+     *
+     * @see #Image(int,int,float[],PixelFormat)
+     * @see #toByteArray(PixelFormat)  
+     */
     public float[] toFloatArray(PixelFormat format) {
         var bytes = toByteArray(format);
         var floats = new float[bytes.length];

test/edu/macalester/graphics/ImageTest.java

@@ -197,6 +197,22 @@ private float[] generateFloatData(int w, int h, int chans) {
         return pixels;
     }
 
+    @RenderingTest(width=200, height=200, modes = { PLAIN })
+    void imageFileProcessing() {
+        Image original = new Image(FOXFLOWER_IMAGE);
+        float[] pixels = original.toFloatArray(Image.PixelFormat.RGB);
+
+        for(int i = 0; i < pixels.length; i++) {
+            pixels[i] = (float) (Math.sin(pixels[i] * Math.PI * 2) + 1) / 2;
+        }
+
+        image = new Image(
+            original.getImageWidth(),
+            original.getImageHeight(),
+            pixels,
+            Image.PixelFormat.RGB);
+    }
+
     @RenderingTest(height=200, modes = { PLAIN })
     void colorPixelConversionToGrayscaleArray() {
         Image colorImage = new Image(FOXBOT_IMAGE);