height map related issue

Question

I am trying to make a program in Java that uses Perlin noise to make a black and white height map. I tried using the code from here to implement the noise. I used the code below to try to make the noise make a height map but what I get is something like this instead of getting a height map.

BufferedImage img;
img = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB );

int[] pixel = ((DataBufferInt)img.getRaster().getDataBuffer()).getData();

for(int i = 0; i < (WIDTH*HEIGHT); i++)
{
    pixel[i] = (int) perlin.PerlinNoise(i, i);   
}

Why do you use an RGB image if you only want grayscale (= *hight-map*)? — halirutan, Jan 03 '14 at 00:26
I couldn't find a way to draw onto the image if it was TYPE_BYTE_GRAY or TYPE_USHORT_GRAY. — Will_Opar, Jan 03 '14 at 00:35

score 2 · Accepted Answer · edited May 23 '17 at 12:15

2

You can use the BufferedImage.TYPE_BYTE_GRAY as follows: Create you noise-array of type int[] where the numbers in the array should be between [0,255]. Let's assume this pixel array is called pixelData, then the following should work

BufferedImage img = new BufferedImage(WIDTH, HEIGHT, 
                                     BufferedImage.TYPE_BYTE_GRAY);
img.getRaster().setPixels(0, 0, WIDTH, HEIGHT, pixelData);

File output = new File("image.jpg");
try {
  ImageIO.write(img, "jpg", output);
} catch (IOException e) {
  e.printStackTrace();
}

If you want to have a complete example, then please look at the following question: Issue with Perlin Noise in Java

edited May 23 '17 at 12:15

Community

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answered Jan 03 '14 at 02:43

halirutan

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Is the permutation[] just random value's for each point you made up for the noise or do they have to be those values? – Will_Opar Jan 03 '14 at 03:38
You mean in the linked *Issue with Perlin Noise in Java* post? This is not my code! It is a reference implementation by Perlin and honestly, I don't know the answer. You have to read the publication. – halirutan Jan 03 '14 at 04:08

height map related issue

1 Answers1