Top-of-Screen shot showing partial photo search

Using Colour Search – with 2 colours and partial search

  • Menu is on the left – COLOUR SEARCH
  • Table (photo) selected “monck_a_picto’
  • Colours Selected Red_C and Clay
  • W(x) min = 1300 max = 1700
  • H(y) min = 600 max = 1100
  • Background selected is white (255,255,255)
  • Result is on the right
  • Shown Original and Plot on first row
  • Shown Markup(composite) and Report second row

Bottom Screen shot showing partial photo search

Using Colour Search – with 2 colours and partial search

  • Menu is on the left – COLOUR SEARCH
  • Table (photo) selected “monck_a_picto’
  • Colours Selected Red_C and Clay
  • Additional Parameters :
    • W(x) min = 1300 max = 1700
    • H(y) min = 600 max = 1100
    • Background selected is white (255,255,255)
  • Result is on the right
  • Shown Report on Search result

Work Notes

Colour Pixel Plotter-related:

Define Colour formula :
As can be seen from the screen shot, a formula is defined by choosing a photo as reference, together with a generic formula. CPP will display the photo and colour ‘template’, so the user can accept that ‘as is’ and click on ‘Find Colour’. The system then will report back the number of pixels found, and plot the ‘hits’ on a white background. The formula can then be edited and a new selection plotted, or it can be saved and be ready to use for another search.

Import Photo :
Each photo registered in CPP will be assigned a filename by the user in the format: Site_Pit_Type, choosing an alphanumeric code for the appropriate Site Name, Pit Name (location within the site), and Type (a Pictograph or a three digit peel number).

Pixel coordinates :
Pixel coordinates representation is x on Width and y on Height. Most photo viewers/editors will show x, y coordinates as related to the photo. And a colour picker to show the pixel’s RGB values.

Search Plot :
A CPP search will always produce a plot – same size as the original – with selected pixels on a white background. It can be used by itself for study, or used to overlay on top of the original for easy matching. The examples above use the original as a background with the plot overlay on top. All plots are included in this document together with the composite. Any photo viewer/editor can be used to study them.

Photo-related:

Focusing Requirement :
Surface features should still be discernable, without being blurred, when the photo is zoomed to 100%. In addition, the edge of the photo should be as clear as possible to the center. Evenness of details is highly desirable.

Lighting Requirement :
Evenness of details is highly desirable.

Multiple photos on same subject :
Due to physical constraints, it may be desirable to use different lenses from different angles/distances to obtain better photos. However, physical references should be used to facilitate their assembly as ‘composites’.

Pictograph-related:

Some Red (faint pink dots) are not targetted by any formula yet; they are around lower left.
The surface of that part seems bending left and away for focus; also no other ‘features’ are nearby or related. A different angle shot may be desirable.

The ‘Oval’ feature is not clearly visible.
The shape’s coordinates are x(1160-1190), y(400-500). There are some ‘red pixels’ identified within; but the whole ‘feature’ looks like a smudge colourwise. It may be a part of something if a close-up can be had for determination.

Possible ‘peel-offs’ – x(640-690) y(800-900).
There are red and clay colours on both sides. Details show a ‘fresh looking surface’ quite different from its surrounding; is it possible that part of this surface had been ‘peeled-off’?

Possible ‘black circle’ – center around x(260) y(800)
There are ‘faint red’ colours that appear to be seeping out from black smudges. It may be just fungus with red composite. It can also be the binding agent of pigment that is the cause of fungus. Or it can be red colour pigments covered by black colour pigments.

Observations and Comments

More detailed photos and more study are needed :
When the photos are examined with 100% zoom, the details become blurred. For example, the lower right corner shows possibly ‘ropes around a rock’ in the shadow. The proposed ‘zones’ drawn from the ‘red/clay’ plot can be used as a base for taking more close-up shots. These will also allow for a more detailed colour formula for each zone for a better outline of components. Currently it is assumed that each ‘zone’ can be studied independently as a pictograph on its own. Especially if a series of pits will be dug, each one will have their own ‘references’. Comparative studies can also be made on the colour differences between different zones.

Visual scale required :
What is the physical size of the entire photo? Actually, the height from the ground to any of the components will give the researcher a better feel. For example, was the ‘drawing’ done standing up? with leveled arm? It also give some reference when zooming for details.

A wide angle shot for better reference :
The left side of the photo seems ‘chopped off’; a photo (or a series of photos) should be taken so the ‘entire’ object can be shown for better reference.

The ‘red’ colour picks from tree-trunk and from soil :
The colours from the ‘red’ plot pick up part of the ‘tree trunk’ and soil below, and should be a consideration if evacuation of soil is planned. Surrounding area features can also provide a ‘setting’ for the culture events.

Dot-like application of colour – and clay seems to form the background for red :
As clearly as can be seen from the partial plot above, the ‘clay’ (possible yellow ochre or clay) seems to both ‘outline’ the ‘red’ as well as its interior image. The two ‘curved’ lines seem to be constructed by dots. This may be due to the uneven surface and the ‘fading’ of ‘paint’, but there may also be other reasons. But the lower left corner also has lots of ‘dots’ like red colour backgrounded with ‘clay’. That is also the reason for a ‘closer’ look.

Moss-like fungus with ‘red/magenta’ colour :
The photo from ‘Shaken Eagle’ shows lots of moss-fungus with different stages of growth (and dying). If that part of the ‘dark’ colours is also moss-fungus, perhaps an expert on that should be consulted. This assumes that the moss-fungus is common to both sites.

A quick analysis of Monck Park Rock pictograph using Colour Pixel Plotter — Raymond Cheng – 2008-06-10