Classical Machine Learning

Select the bright seed pixels

BOTIE

Compare the image with the cutoff. Flatten the mask only for counting, add its entries, and pack the mask and count into the result in that order.
Ready to test
0 passed · 0 failed · 2 not run

An empty floor. Start with the information your machine needs.

Received result

Your answer will arrive here.

Examples, experiments and workspace controls
Live values

Connect a tool's inputs to see what it produces. You can try a branch before connecting it to Result.

Try your own inputs

Use a copy of the example to try your own data. Keep the problem's assumptions in mind, and predict the effect of a change before checking the output. You can also add another branch to compare two ways of doing the calculation.

Start at an output arrow, then click or drag to an input. Drag empty space to pan. Delete removes a selection. Ctrl/Cmd+Z undoes a change.
Context for this challenge

Compare the image with the cutoff. Flatten the mask only for counting, add its entries, and pack the mask and count into the result in that order.

Botie needs bright foreground positions in the seed-tray photograph and a count of selected pixels. Those are two related outputs with different meanings.

Compare every intensity strictly above the cutoff, retain the mask's arrangement and flatten a copy only to sum its selected entries.

Examples and results
Tray intensities
102010
2022030
1020020
Foreground cutoff
100
Required result
[
  [
    [
      0,
      0,
      0
    ],
    [
      0,
      1,
      0
    ],
    [
      0,
      1,
      0
    ]
  ],
  2
]
Tray intensities
510
1520
Foreground cutoff
100
Required result
[
  [
    [
      0,
      0
    ],
    [
      0,
      0
    ]
  ],
  0
]
Try a fresh construction

This clears this draft, including its undo history. Earlier successful attempts stay recorded. Build again without opening hints to record an independent attempt.

Stuck? Inspect a worked construction

The tools below form one possible solution. You can assemble it, follow its signals, and undo that change to return to your own construction.

Assumptions and test precision

The first result is a mask; the second is a pixel count. A global brightness cutoff can fail under shadows or similar foreground and background intensities. Numerical tests allow a difference of 0.001. Lists and structures must also have the right shape.

A small tray at a lower brightness cutoff

This check uses the pieces from “Keep the seed mask beside its pixel count”.

BOTIE

Predict the two-by-two foreground mask and its foreground-pixel count. The existing rule requires intensity strictly above the supplied cutoff.
Tray intensities
4041
040
Foreground cutoff
40

Use a number, text, or an array matching the requested result. For a matrix, put each row in brackets. Saving your prediction runs your current construction on these inputs and checks the earlier examples too.

Build a construction in the workspace above first. This case will test those pieces.

Why does a count of two foreground pixels not necessarily mean two seeds, and why should the mask be kept even after counting?

Thresholding identifies pixels under a brightness rule. Object grouping requires additional spatial reasoning.

The first result is a mask; the second is a pixel count. A global brightness cutoff can fail under shadows or similar foreground and background intensities.

Work through the Python challenges →
Continue the courseCleaning Masks With Morphology →
← Images as Arrays