Compositing Kowloon Walled City Cross Sections

Kowloon Walled City Cross Section, Colossal scan (top), Amazon scan (middle), composite (bottom). Higher resolution images below.

Images discussed:

Kowloon City Cross Section, This is Colossal scan, 4500×1636
Kowloon City Cross Section, Kowloon Large Illustrated (1997), Amazon book scan, 2560×956
Composite Kowloon City Cross Section, 3166×925
Kowloon City Cross Section, scan, 4716×1754

I first saw an image of the cross section of Kowloon Walled City in 2014. It is a wonderful illustration of the infamously dense city within a city that once existed in Hong Kong. The attention to detail is extraordinary, with a dozen birds, hundreds of glowing orange human silhouettes, and the outlines of thousands of household objects filling up the canvas. Each room is unique, every shape is different from the others of its type. The messes of television antennae on the roofs initially appear to be trees, while the plants inside apartments are colored solid green, setting them apart from the other hollow, unfilled objects surrounding them.

The busy city shines in its full 4500×1636 resolution. Every silhouette tells a story. As waking arms stretch over a bottom bunk bed, someone else falls asleep outside on the roof. Behind a wall on which a man carrying a large bag leans, a pair of people sit facing each other across a folding table and a small child climbs up on a counter. It’s not clear whether the man with the bag is aware of the people on the other side or if they are strangers to him.

Something else about the image stands out: it was a sloppy scan, of shoddy and inconsistent quality. There are obvious vertical division lines showing where the separate scans overlapped (not unlike the idea of “seams” in some digital images, which I wrote a bit about earlier this week), and varying color profiles and levels. The bottoms of the page numbers and some text are cut off on the edges, and entire vertical slices of buildings gradually slide into the dividing gutter on the left side of the image.

I am pretty sure that the scan which experienced a mini-revival on the internet a few years ago was from a This Is Colossal article, published November 4, 2014, which featured the illustration and the book it originally appeared in. The book’s title is in Japanese, but is translated on Amazon as Kowloon Large Illustrated (1997).

4500×1636, Kowloon Walled City Cross-Section, Kowloon Large Illustrated (1997), This Is Colossal scan. (click to view full image)

By my count, this same 4500×1636 image, first appearing on This Is Colossal, appears 46 different times at full resolution on Google Image Search, along with many more smaller versions. This is a very large amount of copies. I consider myself to be a moderately experienced Image Searcher, and I rarely see so many different domains hosting unique Google-accessible copies of the same high-resolution image. To me, this is a sign of an underground classic image.

A few months later, sometime in early 2015, I had access to a good printer, so I printed out the beautiful Kowloon cross section on some nice paper and hung it up on a wall above a new, uncomfortable ugly chair that I never sat in. The following year I moved to a different city, and the glossily posterized Kowloon has been rolled up in a tube in my closet ever since.

A @smashedmcdouble tweet from the other day reminded me of the Kowloon cross section, and upon revisiting it I immediately noticed something new in the familiar image. Not only were certain page numbers and text cut off by the sloppy scan, but almost an entire page – “Page 12” – was missing as well. Knowing that I wouldn’t be able to adequately explain the issue in 280 characters (a hunch supported by this post), I made a reference image to highlight the missing section and posted it on Twitter.

The Mystery of pg. 12 reference image, derived from This Is Colossal scan

Shortly thereafter, @justinetlai blew the lid off the entire mystery, finding a different scan on the Amazon page for Kowloon Large Illustrated, the book which contains the cross section. The listing for the over-sized, 14.3″ x 10.3″ book includes three preview photos: the front cover, back cover, and the Kowloon Walled City cross section with the elusive Page 12 that was missing on nearly all of the other versions of the image floating on the Internet.

Amazon scan of Kowloon Walled City Cross Section (including pg 12), 2560×956 (click for full image)

It turns out that Page 12 is dominated by stairwells with vertical, solid pale green backdrops. The two main buildings of the page are offset from each other by half a floor (see the image above), which must have created a conundrum for whoever had to label the floors. If the floors were numbered normally (1, 2, 3…) in each building (see Fig. 1 below), a person walking up the stairs would see Floor 1 of the building on the left, go up half a flight of stairs to Floor 1 of the building on the right, up the stairs to Floor 2 on the left, Floor 2 on the right, and so on. The floor numbers could be reconfigured to make more sense to a traveler of the stairwell (Fig. 2), but then then every other floor would be skipped in the numbering of each building. A solution that might be acceptable to both the building residents and stairwell travelers (Fig. 3) would assign subfloors (1a, 1b, 2a, 2b, or 2blue, 2red, etc) so that each stairwell landing has a unique identity without skipping any numbers. Or maaaybe they came up with an even better system.

Three possible solutions to the stairwell conundrum (click for full image)

But soon after celebrating the recovery of the missing Page 12, I noticed that the Amazon scan was missing the left side of the image that appears in the widely shared This Is Colossal image. In other words, there is no version of the cross section that is complete – they’re both missing a side. UNTIL NOW.

It certainly isn’t perfect, but I made a composite image combining the This Is Colossal and Amazon scans (below).  The Amazon scan is lower resolution than the Colossal scan, so I had to shrink the Colossal image (losing some detail in the process) to get things to line up properly. In general, the Amazon scan is much cleaner, despite its lower resolution, so I used it as the bulk of the composite. I only used the Colossal scan image to fill in the missing left of the Amazon scan. The two scans also have very different color profiles and image qualities so I had to do some color matching and level balancing in Photoshop, and even then it’s a little weird. But the weirdness of it is in keeping with the history of this image,  and to my knowledge it is now the only version of the Kowloon Walled City Cross Section on the internet that contains the complete scan.

3166×925,Kowloon Walled City Cross Section, composite image of This Is Colossal and Amazon book scans. (click to view full image)

I suppose that someone could just buy the real book it appears in and do a decent job of scanning it, but I no longer believe in miracles.


In the This Is Colossal article, another earlier blog post is credited as the source: a March 30, 2010 published on The post features a different scan which is very similar to the Colossal image, but slightly larger, and revealing even more sloppiness. The scans are tilted at an angle, which makes white space appear at the borders. The Colossal image crops these white spaces out, which is also why it ended up cutting off some of the page numbers. My goal is to find out who did the original sloppy scan of the book which is the true origin of so many of the internet’s images of the Kowloon cross section. The post references another earlier blog post (at as the source, but the website no longer exists.