diff --git a/Manifest.toml b/Manifest.toml
index ae3e78a..7b38006 100644
--- a/Manifest.toml
+++ b/Manifest.toml
@@ -2,7 +2,7 @@
 
 julia_version = "1.11.4"
 manifest_format = "2.0"
-project_hash = "0a18a0873213e0e8660a5eb202a1fa9f1621a652"
+project_hash = "ec502e8d73a739a6239b751344af945fa59e7806"
 
 [[deps.AbstractFFTs]]
 deps = ["LinearAlgebra"]
diff --git a/Project.toml b/Project.toml
index 9661941..a619579 100644
--- a/Project.toml
+++ b/Project.toml
@@ -7,10 +7,12 @@ version = "0.1.0"
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"
 Images = "916415d5-f1e6-5110-898d-aaa5f9f070e0"
 Luxor = "ae8d54c2-7ccd-5906-9d76-62fc9837b5bc"
+Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 VideoIO = "d6d074c3-1acf-5d4c-9a43-ef38773959a2"
 
 [compat]
 FileIO = "1.17.0"
 Images = "0.26.2"
 Luxor = "4.2.0"
+Statistics = "1.11.1"
 VideoIO = "1.1.1"
diff --git a/src/image.jl b/src/image.jl
new file mode 100644
index 0000000..3eaf2f9
--- /dev/null
+++ b/src/image.jl
@@ -0,0 +1,8 @@
+using Images
+
+"""
+Converts image to grayscale
+"""
+function greyscale(c::Images.RGB)::Real
+    return Real(c.r)
+end
diff --git a/src/stock_index_composition.jl b/src/stock_index_composition.jl
new file mode 100644
index 0000000..f27ce2a
--- /dev/null
+++ b/src/stock_index_composition.jl
@@ -0,0 +1,103 @@
+using Base
+import Luxor as L
+
+"""
+Colour of a component given its fluctuations
+"""
+function colour_of_diff(diff::Real)::Tuple{Real,Real,Real}
+    if diff > 0
+        return (0.5,1,0.5)
+    else
+        return (1,0.5,0.5)
+    end
+end
+
+component_text_size = 20
+
+@kwdef struct Component
+    pos::Tuple{UInt, UInt}
+    size::Tuple{UInt, UInt}
+    name::String
+    diff::Real
+end
+
+sector_title_font_size = 16
+sector_title_height = 20
+
+@kwdef struct Sector
+    name::String
+    pos::Tuple{UInt, UInt}
+    size::Tuple{UInt, UInt}
+    components::Array{Component}
+end
+
+@kwdef struct CompositionDiagram
+    sectors::Array{Sector}
+end
+
+"""
+Draws stock index composition chart
+"""
+function draw(diagram::CompositionDiagram, size=(800, 600))
+    L.Drawing(size[1], size[2], :png)
+    L.background("black")
+    for sector in diagram.sectors
+        L.sethue("gray")
+        L.rect(L.Point(sector.pos), sector.size[1], sector.size[2], action = :fillpreserve)
+        L.setline(2)
+        L.strokepath()
+        L.sethue("white")
+        L.setfont("Helvetica", sector_title_font_size)
+        L.settext(
+            sector.name,
+            L.Point(sector.pos),
+            halign="left",
+            valign="top",
+        )
+        L.setfont("Helvetica", component_text_size)
+        for component in sector.components
+            pos = sector.pos .+ component.pos
+            L.setcolor(colour_of_diff(component.diff))
+            L.rect(L.Point(pos), component.size[1], component.size[2], action = :fillpreserve)
+            L.sethue("white")
+            L.setline(5)
+            L.strokepath()
+            L.settext(
+                component.name,
+                L.Point(pos .+ component.size ./ 2),
+                halign="center",
+                valign="bottom",
+            )
+            L.settext(
+                "$(component.diff)%",
+                L.Point(pos .+ component.size ./ 2),
+                halign="center",
+                valign="top",
+            )
+        end
+    end
+    L.finish()
+end
+
+diagram = CompositionDiagram(
+    sectors=[
+        Sector(
+            name="technology",
+            pos=(0,0),
+            size=(200,300),
+            components=[
+                Component(pos=(0,20), size=(200,200),name="AAPL", diff=0.5),
+                Component(pos=(0,200), size=(200,100),name="GOOG", diff=-0.3),
+            ],
+        ),
+        Sector(
+            name="resources",
+            pos=(200,0),
+            size=(200,200),
+            components=[
+                Component(pos=(0,20), size=(200,150),name="OIL", diff=0.1),
+            ],
+        ),
+    ],
+)
+draw(diagram)
diff --git a/src/tdpacking.jl b/src/tdpacking.jl
new file mode 100644
index 0000000..bb5959a
--- /dev/null
+++ b/src/tdpacking.jl
@@ -0,0 +1,132 @@
+using Base
+using Statistics, Images
+import Luxor as L
+
+@kwdef struct Region
+    pos::Tuple{Int,Int}
+    size::Tuple{Int,Int}
+    # If true, this region increases from x to y. This direction variable steers
+    # the direction of cut.
+    dir::Bool
+end
+
+# Time-dependent packing
+@kwdef struct Rect
+    pos::Tuple{Int,Int}
+    size::Tuple{Int,Int}
+    color::Real
+end
+
+function area(r::Rect)::Int
+    return r.size[1] * r.size[2]
+end
+function aspect_ratio(r::Rect)::Real
+    return r.size[1] / r.size[2]
+end
+
+"""
+    divide_image(img::Matrix{}, size_min::Int=16, size_max::Int=256)
+
+Divides an image into rectangles of the same colour. The rectangles are not
+allowed to have extreme aspect ratios. There is a minimal size of each retangle.
+"""
+function divide_image(img::Matrix{}; size_min::Int=16, size_max::Int=128, threshold_aspect::Real=3.0, threshold_std::Real=0.4)::Array{Rect}
+    remainder = [Region(pos=(1,1), size=size(img), dir=false)]
+    result = Rect[]
+
+    # Loop until the entire field is filled
+    while length(remainder) > 0
+        section = pop!(remainder)
+
+        (px, py) = section.pos
+        (sx, sy) = section.size
+
+        @assert px + sx - 1 <= size(img)[1]
+        @assert py + sy - 1 <= size(img)[2]
+
+        width = 1
+        height = 1
+
+        width_max = min(sx, size_max)
+        height_max = min(sy, size_max)
+
+        # Try to expand this rectangle to the maximum size
+
+        while width < width_max || height < height_max
+            subimg = img[px:px+width-1, py:py+height-1]
+            if std(subimg) >= threshold_std
+                break
+            end
+            colour = mean(subimg)
+            ar = width / height
+
+            if width < width_max && ar < threshold_aspect
+                width += 1
+            elseif height < height_max && ar > 1/threshold_aspect
+                height += 1
+            else
+                break
+            end
+        end
+        @assert width <= sx
+        @assert height <= sy
+
+        subimg = img[px:px+width-1, py:py+height-1]
+        rect = Rect(
+            pos=section.pos,
+            size=(width, height),
+            color=mean(subimg),
+        )
+        push!(result, rect)
+
+        if section.dir
+            if width < sx
+                push!(remainder, Region(
+                    pos=(px + width, py),
+                    size=(sx - width, height),
+                    dir=false,
+                ))
+            end
+            if height < sy
+                push!(remainder, Region(
+                    pos=(px, py + height),
+                    size=(sx, sy - height),
+                    dir=true,
+                ))
+            end
+        else
+            if height < sy
+                push!(remainder, Region(
+                    pos=(px, py + height),
+                    size=(width, sy - height),
+                    dir=true,
+                ))
+            end
+            if width < sx
+                push!(remainder, Region(
+                    pos=(px + width, py),
+                    size=(sx - width, sy),
+                    dir=false,
+                ))
+            end
+        end
+    end
+
+    return result
+end
+
+"""
+    draw_rect(size::Tuple{Int, Int}, rects::Array{Rect})
+
+Displays the divided image in greyscale.
+"""
+function draw_rect(size::Tuple{Int, Int}, rects::Array{Rect})
+    L.Drawing(size[1], size[2], :png)
+    L.background("black")
+    for rect in rects
+        c = N0f8(rect.color)
+        setcolor(c, c, c)
+        L.rect(L.Point(rect.pos), rect.size[1], rect.size[2], action = :fill)
+    end
+    L.finish()
+end