Week 04 · lesson

Lab: Slide the Convolution Window

Mission

Run the local Convolution Window Lab. Move one 3 × 3 kernel across a fixed 6 × 6 binary image, preserve one complete calculation, compare two feature maps, and export a Convolution Evidence Record.

Starting state

The baseline uses the vertical kernel at output position [0,0], stride 1, and no padding. The 6 × 6 input produces a 4 × 4 feature map. The vertical and horizontal kernels are hand-designed teaching filters; no model is trained.

Guided start

  1. Keep Vertical edge selected at row 0, column 0.
  2. Run convolution and locate the covered 3 × 3 patch.
  3. Read all nine signed products in the calculation table.
  4. Add them and confirm the stored response.
  5. Move only the column to 1 and rerun.

The input, kernel, stride, and rule stayed fixed. Only window position changed.

Procedure

  1. Predict where the vertical kernel will produce its greatest absolute response.
  2. Preserve the [0,0] patch, nine products, sum, and response.
  3. Move the window by one column, then one row. Connect each response to its feature-map cell.
  4. Record the vertical map's maximum absolute response and first position.
  5. Change only the kernel to horizontal; keep the image fixed.
  6. Record the horizontal maximum and first position.
  7. Preserve your first feature claim before correcting it.
  8. Complete Observation, Measurement, Decision, and Limitation.
  9. Export the JSON and confirm it names ai-for-beginners-convolution-window-lab.

Success criteria

  • one calculation contains nine products and the correct signed sum;
  • vertical and horizontal kernels use the same input;
  • both maximum responses and positions are recorded;
  • the before/after claim remains visible; and
  • the limitation rejects object identity, learned-model, transfer-performance, general-accuracy, and deployment claims.

Troubleshooting and boundary

Moving the window changes the highlighted calculation, not the already computed full map. If a sum is wrong, multiply matching positions before adding all nine signed values. Backend View is fictional local output, not a production log.

Use only supplied data. The Lab activates no camera, uploads no image, contacts no service, downloads no model, and makes no real classification decision.

Robotnix Lab · contract v1

AI for Beginners Convolution Window Lab

Move a fixed 3-by-3 kernel across one supplied image, inspect every product, and compare vertical and horizontal feature maps.

Help and boundaries

A deterministic browser simulator calculates supplied binary grids. It trains no model and contacts no service.

No personal data, private prompts, or API keys. This Lab makes no hidden remote writes and does not persist your work after the page session.

No result trains a model, identifies an object or person, controls a device, or supports a deployment decision.

Lab draft is active for this page session only.

Objectives

  • Trace one 3-by-3 patch through nine products to one stored response.
  • Compare vertical and horizontal feature maps while holding the input fixed.
  • Repair a claim that mistakes a local pattern response for object identity.

Procedure

Workbench

Move the window. Keep the calculation inspectable.

The binary cross and both kernels are fixed teaching records. This is convolution arithmetic, not a trained CNN.

Local experiment · deterministic simulation

Convolution Window Simulator

Move one fixed kernel across a supplied image and connect each local calculation to one feature-map position.

A readable explanation of the same local run.

  1. 01
    Input GridWhich supplied image values stay fixed?
  2. 02
    Filter KernelWhich nine weights are applied at every position?
  3. 03
    Window PositionWhich 3-by-3 patch is currently covered?
  4. 04
    Nine ProductsWhat does each matching pixel-weight pair produce?
  5. 05
    Local ResponseWhat sum is stored for this position?
  6. 06
    Feature MapWhere does the filter respond across the full image?
  7. 07
    Filter ComparisonWhat changes when only the kernel orientation changes?
  8. 08
    Claim BoundaryWhat does this local pattern evidence fail to identify or prove?
Read the student trace as text
robotnix-ai-lab :: local deterministic convolution
Select a kernel and window position, then run convolution.
No camera, trained model, or network service is active.
Input Grid · highlighted 3 × 3 patch
vertical Kernel
Feature Map · selected response 2
Nine products for output [0,0]
Patch positionPixelWeightProduct
[0,0]0-10
[0,1]000
[0,2]111
[1,0]0-10
[1,1]000
[1,2]111
[2,0]1-1-1
[2,1]100
[2,2]111
Response sum2
Kernel · vertical | Window Position · [0,0] | Stride · 1 | Padding · noneResponse · 2

Maximum Absolute Response · 2 at [0,0] · signed 2

Controlled comparison on the same binary cross
KernelMap sizeMaximum absolute responseFirst positionSigned value
Vertical4 × 42[0,0]2
Horizontal4 × 42[0,0]2

Lab boundary: these fixed kernels expose local pattern calculations. They do not learn weights, identify an object, test a classifier, or establish performance on other images.

Text and static fallback

Every input, kernel weight, patch value, product, response, position, and complete feature map appears as selectable text and in accessible tables.

The 6-by-6 binary cross produces one 4-by-4 map per 3-by-3 kernel at stride 1 with no padding; the included tables expose every response.

Evidence record

Record only the evidence requested. Do not enter names, personal information, private prompts, or credentials. This draft stays in memory only unless you explicitly export it.

Success criteria

  • One feature-map cell is connected to nine signed products and their sum.
  • Vertical and horizontal maps are compared on the same supplied image.
  • The original claim remains visible beside a response-bound revision.
  • The conclusion rejects object identity, training, general accuracy, and deployment claims.

Complete every procedure step and required evidence field before export.

Vocabulary lab

Flip the idea, not just the card

Explain the term before you reveal the back. Then compare your explanation with the definition, example, and warning.

1 / 5
Read all terms without animation
convolution window
The movable region aligning one kernel with one image patch. Example: A 3-by-3 window at output row zero, column one. Do not confuse it with: It is not a view of the whole image.
signed response
A convolution result whose positive or negative sign preserves pattern direction. Example: Reversing light and dark can reverse the response sign. Do not confuse it with: The sign is not a pass/fail label.
maximum absolute response
The response farthest from zero, ignoring sign for the comparison. Example: Negative four and positive four both have magnitude four. Do not confuse it with: It is not automatically the most important object feature.
controlled filter comparison
A test changing the kernel while holding input and other settings fixed. Example: Vertical versus horizontal kernel on the same cross. Do not confuse it with: Changing image and filter together hides the cause.
Convolution Evidence Record
An artifact preserving settings, calculations, measurements, conclusion, and limitation. Example: The JSON exported from this Lab. Do not confuse it with: It is not proof of a trained or deployed CNN.