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authorKT <tran0563@umn.edu>2021-09-06 19:07:33 -0500
committerKT <tran0563@umn.edu>2021-09-06 19:07:33 -0500
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parentAdded missing images for the A6 worksheet (diff)
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@@ -24,6 +24,10 @@ documentation](https://processing.org/reference/color_.html) and/or the
[tutorial explaining color in
Processing](https://processing.org/tutorials/color/).
+Here are a couple of questions to get you thinking about how to work with
+pixel arrays and colors in this format. Note: These are very brief questions
+in this first worksheet, so this may not take you long at all. That's ok!
+
## Q1: Indexing
@@ -41,6 +45,12 @@ information from `inputImg` to help you.
```
PImage inputImg = loadImage("test.jpg");
+// your code should work for any valid values for row and column, we've
+// randomly picked the values (2, 2) here as an exmaple.
+int row = 2;
+int column = 2;
+
+// write your answer in terms of the row and column defined above
int index1D = /* --- Fill this in --- */;
```
@@ -50,8 +60,10 @@ int index1D = /* --- Fill this in --- */;
The image processing technique known as *thresholding* will be useful while
creating your Text Rain. During the thresholding operation, if a pixel's
grayscale value is less than `threshold`, then it becomes black. If the
-value is greater than `threshold`, it becomes white. You can use the green
-channel of the color as the grayscale value.
+value is greater than or equal to `threshold`, it becomes white. In the example below,
+assume the image has already been converted to grayscale. This means the
+red, green, and blue channels are all equal. So, you can get the grayscale
+value by accessing any one of the color channels red, green, or blue.
In the code block below, write a Java code snippet for thresholding one pixel
(`inputPixel`) to black or white.