Example: Zooming and Scaling

Functions > Image Processing > Geometric Transforms > Example: Zooming and Scaling

Example: Zooming and Scaling

Use the zoom function to zoom or scale an image or a matrix.

For information on using this example, refer to About Image Processing Examples.

Zooming an Image

1. Read in an image:

Click to copy this expression

(pattern.bmp)

2. Set the horizontal and vertical scales then apply the zoom function to the image:

Click to copy this expression

Click to copy this expression

Click to copy this expression

Click to copy this expression

(pattern_z1.bmp)

The zooming results in halving the image width and doubling its height.

Zooming a Matrix

1. Define a 3 x 4 matrix, and then use an equation to set the value of its elements:

Click to copy this expression

Click to copy this expression

Click to copy this expression

2. Evaluate the matrix:

Click to copy this expression

3. Apply the zoom function to the matrix:

Click to copy this expression

Click to copy this expression

<region id="ID0EGBBX" top="1368" left="24" height="98.288" width="292.628333333333" xmlns="http://schemas.mathsoft.com/worksheet50">
  <math>
    <eval xmlns="http://schemas.mathsoft.com/math50">
      <apply>
        <id>zoom</id>
        <sequence>
          <id>M</id>
          <real>2</real>
          <real>3</real>
        </sequence>
      </apply>
      <result>
        <matrix rows="6" cols="12">
          <real>0</real>
          <real>0</real>
          <real>1</real>
          <real>1</real>
          <real>2</real>
          <real>2</real>
          <real>0</real>
          <real>0</real>
          <real>1</real>
          <real>1</real>
          <real>2</real>
          <real>2</real>
          <real>0</real>
          <real>0</real>
          <real>1</real>
          <real>1</real>
          <real>2</real>
          <real>2</real>
          <real>1</real>
          <real>1</real>
          <real>2</real>
          <real>2</real>
          <real>3</real>
          <real>3</real>
          <real>1</real>
          <real>1</real>
          <real>2</real>
          <real>2</real>
          <real>3</real>
          <real>3</real>
          <real>1</real>
          <real>1</real>
          <real>2</real>
          <real>2</real>
          <real>3</real>
          <real>3</real>
          <real>4</real>
          <real>4</real>
          <real>5</real>
          <real>5</real>
          <real>6</real>
          <real>6</real>
          <real>4</real>
          <real>4</real>
          <real>5</real>
          <real>5</real>
          <real>6</real>
          <real>6</real>
          <real>4</real>
          <real>4</real>
          <real>5</real>
          <real>5</real>
          <real>6</real>
          <real>6</real>
          <real>9</real>
          <real>9</real>
          <real>10</real>
          <real>10</real>
          <real>11</real>
          <real>11</real>
          <real>9</real>
          <real>9</real>
          <real>10</real>
          <real>10</real>
          <real>11</real>
          <real>11</real>
          <real>9</real>
          <real>9</real>
          <real>10</real>
          <real>10</real>
          <real>11</real>
          <real>11</real>
        </matrix>
      </result>
    </eval>
    <resultFormat>
      <decimal precision="round-trip-decimal-places" show-trailing-zeros="false" radix="dec" imaginary-value="i" />
      <matrix size="12,12" offset="0,0" />
    </resultFormat>
  </math>
</region>

The zoom produces a 6 x 12 matrix.