018-hirst-painting/docs/milestones/mil-001-palette.md

MIL-001: Colour Palette

Metadata

Key	Value
ID	MIL-001
CrossReference	BC-001
Language	en
Domain	it

Version History

Date	Status	Author	Reviewer	Change	Commit
2026-10-07	Accepted	Jens Tirsvad Nielsen	S01	Initial version	b823d1f

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Purpose

This gate decides whether the colour palette is usable, so that the painting phase can build on it. The palette must come from the reference image through colorgram, must contain no white shades, and the toolchain it depends on (colorgram and the turtle graphical toolkit) must work on the developer machine.

Deliverable

A palette function in the program's source file under src/ that reads the reference image with colorgram, drops white shades and returns the remaining colours as RGB tuples, together with the tests that check it and the printed palette of the real image.

Go / No-Go Criteria

#	Criterion (objectively checkable)	Go	No-Go
1	import colorgram and import turtle succeed and a turtle window opens on the developer machine	Both imports succeed and the window opens	An import fails or no window opens
2	The palette of the reference image has at least 2 colours (SC3)	2 or more colours printed	0 or 1 colour
3	The palette has no colour with red, green and blue all at 240 or above (SC3)	0 such colours in the printed palette	1 or more such colours
4	The tests of the white-shade filter and of the palette pass	All tests pass	Any test fails
5	The phase code has a review record against qc-programming-python with verdict Go (SC7)	RC-* verdict Go	Go-with-conditions or No-Go, or no record

Dependencies

Depends on	Reason
None	The baseline documents are Accepted; this is the first gateway

Traceability

Business Case objective / KPI / user story	Reference
O2: palette from a reference image with colorgram, without white shades	BC-001; criteria 1 to 4 and SC3
O5: delivery through the framework, code reviewed against qc-programming-python	BC-001; criterion 5 and SC7

No use case or user story applies: every task is a technical step, so the Tasks column "Needs its own Use Case/User Story?" says No throughout.

Ownership

Role	Stakeholder ID (SA)
Owner	S01
Approving reviewer	S01

Target Date

2026-10-09 — inside the one-week limit of BC-001 (2026-10-07 to 2026-10-14), and leaves five days for the painting phase.

Tasks

#	Task	Summary	Needs its own Use Case/User Story?	Reference
1	Check the toolchain	Confirm that Python 3 with Tk (the graphical toolkit behind turtle) runs import turtle and opens a window, install colorgram with pip, and record the versions. The Business Case lists a missing toolchain as a risk, so this comes before any other work depends on it.	No
2	Write the white-shade filter	Write a function that drops every colour whose red, green and blue are all at or above 240; the threshold is a named constant (SC3 of the Business Case). It needs no image, so it can be written and tested first.	No
3	Add tests for the white-shade filter	Add tests under tests/ that feed the filter synthetic colours (pure white, near-white, an ordinary colour) and check which are kept. They pin down the threshold before the real image is involved.	No
4	Get the reference image into the project	S01 supplies the reference image the lecture uses; store it in the repository and note its path. Without it the palette cannot be extracted, and the location is an open issue of the Project Plan.	No
5	Write the palette extraction and check the palette	Write a function that reads the image with colorgram, turns each extracted colour into a red-green-blue (RGB) tuple, applies the filter and returns the list (O2). Print the palette of the real image and check it against SC3: at least 2 colours and no white shade. The painting phase imports this function.	No
6	Review the phase code against qc-programming-python	Check the code of this phase against framework/qc/qc-programming-python.md and record the result as an RC-*; a Go verdict is Go criterion 5 (SC7).	No

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