The Unplanned Pano

Panoramas are fun, even unplanned ones

This old, long “retired”, gasoline station intrigued me. We were driving along in the rural part of Georgia, up in the northern part, when we came upon this sight. We stopped and I took a number of photos. Only when I was doing my post-processing back home did I realize that I had not taken a overall photo that showed the whole place.

Well, that what the “Create” tab in Photo Gallery is for. The first photo showed the building nicely, the third one included the fuel island, there were a number of other views as I walked around the place, and by the tenth photo I had gotten back close to the starting point and showed the pumps, including the ancient one.

Here are the two shots that together cover the whole place.

You can clearly see that I had not taken these photos from the same spot. Making a pano from these would be asking a great deal from Photo Gallery. And indeed it was asking too much. Here is what it could do. Amazing as it is, but the top left of the marque sign just didn’t match.

Old Gas Station - Pano

Old Gas Station – Pano

So on to the nest better tool, in fact the best there is, Microsoft Image Composite Editor. It too had problems, I tried the different planar motion settings and rotating motion. There were still disturbing stitching artifacts. So I did some perspective correction on each image and tried again. That was better.

Old Gas Station - ICE pano

Old Gas Station – ICE pano

A fairly good stitch but the building was way too distorted. Some more fiddling and this was more acceptable. There is a bend in the fuel island base, but I thinks it is not too bad.

Old Gas Station

Old Gas Station

Now with some cropping we have a pretty good photo of the whole place. It still amazes me what Image Composite Editor can do, even with images that clearly were not taken with stitching in mind.

Old Gas Station

Old Gas Station

 

Also see my post at Two Cameras – Two ViewsArtifacts: Fuel Pump


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© 2016 Ludwig Keck

Perspective correction using Microsoft Image Composite Editor

A prior post here showed how to use Microsoft Image Composite Editor, “ICE”, to make perspective corrections to panoramas (Perspective correction for panoramas). How do you make a perspective correction in a single photo? ICE, after all, is a compositing, stitching program and will give an error message when you try to load just one photo.Perspective distortion

If you do not have access to a full-fledged photo editing program, you can still use the free Microsoft Image Composite Editor to do that job.

ICE requires a minimum of two photos to operate. For stitching photos together, it’s primary purpose, the images must overlap so it can find the matching areas and combine the photos into a large composite.

Can it handle photos that overlap completely? Yes, it can. So a photo plus a copy of that photo fulfill the requirement of two images. It just so happens that there is 100% overlap. ICE can handle that.

loading photos into ICE

So, starting in Live Photo Gallery, make a copy of the photo you wish to correct. Select both the original and the copy. On the Create tab click More tools, then click Create Image Composite.

(If you do not have ICE installed this will not work, of course. Download ICE from the Microsoft Research Image Composite Editor download page.)

Live Photo Gallery starts ICE and loads the selected photos.set camera motion

In ICE the two photos will be recognized as “Planar Motion 1” for camera motion in the Stitch box (lower left). Set this option to Rotating Motion, see the illustration here.

Once this option is set, the menu bar above the image will show a little cube. Click that cube. An additional control will be added, “Projection”. In this control you can select how the image is to be translated. It will already show “Perspective”. The other projection options, cylindrical and spherical, are not applicable to this use. We want to make a perspective correction.

set projection

When a photo is taken of a building, or other subject, with the camera titled up or down to get the whole object into the frame, the resulting photo will show strong converging lines. The building, see photo higher up in this article, looks like it is falling in on itself. We call it perspective distortion, but it is how the camera sees the world.

This is a natural consequence of how optics works. Things farther away look smaller, hence the result. This also happens in our eyes. But we humans have a powerful built-in computer – our brain. We know the flagpole stands up vertically and that the walls of the building are vertical. When we stand in front of the building we do not perceive the converging lines, although we see them exactly the same as the camera.

In a photo, however, these converging lines look all wrong. Hence the need for perspective correction. The Image Composite Editor makes this correction easy. Just drag the image up or down, even side to side.

Microsoft Image Composite Editor

As you drag the image, ICE “distorts” it to modify the perspective. Moving the image up stretches the top out. You can move it sideways and the image area will be stretched appropriately. You can see this in real time so this process is very easy.

When you are happy with the result, click Apply.  You can then select the output file format and other parameters in the Export block. The Export to disk button initiates the file save procedure.

One bit of caution: You can make the perspective correction “perfect” so that all vertical lines will be truly vertical. When you look at that picture, however, it may not look perfect at all. It may, in fact, appear that the building is now out of proportion and “growing” outward at the top. Here are a couple of images of the building shown at the top. One is completely corrected, the other still has some converging lines. You will likely agree with me that a bit of under correction produces the better result.

Full perspective correction some perspective under-correction

Click on the photos for larger views.

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© 2012 Ludwig Keck

Vertical Panoramas

No, that is not an oxymoron. In fact, vertical panoramas are quite common. Most of us think of panoramas as wide views of spectacular landscapes, but they can be wide, or high, or just large and detailed images. Vertical panoramas have the nice advantage of fitting well into web pages as you can see here.LJK_2619-30-Stitch - Copy (270x1000)

The panorama here is of a huge tulip poplar tree at McDaniel Farm Park in Duluth, Georgia, just starting to leaf out this spring. This image was composed of twelve individual photos.

So how does one make a vertical panorama?

The technique is the same as for a “normal”, horizontal, panorama. You start by taking overlapping pictures of the subject. I like to overlap quite generously so I don’t accidentally come up short. Here is one of the photos that make up this composite.

LJK_2625-800

You can see the others by clicking on the photo (above), the link leads you to my Photosynth of the set.

To make a  composite set use Windows Live Photo Gallery. Select the image thumbnails you want to combine, click the Create tab then Panorama. The photos do not need to be in order, they do need to overlap. There is no need to tell Live Photo Gallery what kind of composite you want, it analyzes the images and combines them in the correct way. The panorama at the right was made that way and then cropped.

My favorite tool for complex composites is Microsoft Image Composite Editor. Click on the photo at right to see the uncropped output from “ICE” – also as a Photosynth.

I have already illustrated one way to show of a large composite with Photosynth. There is another way I like using Zoom.it:

Zoom.it of Giant Tulip Poplar Tree

The zoomit image is based on the WLPG panorama made as a full resolution JPG (100% quality setting). This made the image 48.4 MB – close to the SkyDrive upload limit of 50 MB. The image size is 4534 pixels wide by 11639 pixels high (this includes the black areas illustrating how the photos overlap).

 

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Panoramas of things that are straight

Panoramas are popular for showing all that you can see around you. But what if you want to show something that is straight? Consider a street. You are standing on one side and want to show everything on the other side up and down the street. Your camera lens is likely not wide enough to take in everything from full left to full right. A set of photos can be stitched together into a panorama. Windows Live Photo Gallery has a Create > Panorama feature that works quite well. I like to use Microsoft Composite Editor because it offers more adjustment features and is very easy to use.

All it takes is a set of photos that show the scene step by step. The content of the photos has to overlap about a third to help the stitching program do its job. Here is a panorama of a street scene.

LJK_2125-31-ICE

The left end of the photo shows the street looking down to the left, and the right edge looks to the right. The street looks like it bends. The individual pictures were taken from one position – that is the normal way to make panoramas.

Here, to explain what happens in more detail, is a set of photos showing a straight wall of Fort Pulaski.

LJK_2262 (3872x2592) (100x67)LJK_2263 (3872x2592) (100x67)LJK_2264 (3872x2592) (100x67)LJK_2265 (3872x2592) (100x67)LJK_2267 (3872x2592) (100x67)LJK_2268 (3872x2592) (100x67)

Six photos were taken from the same place. That’s what they look like. When you look to the left or the right the farther end of the wall looks smaller. That is normal, the way we see the world. Combining them into a panorama results in an image that has the same characteristics as the one of the street.

LJK_2262 (3872x2592)_stitch_thumb

It doesn’t look straight. Can something be done? Yes. Instead of taking the pictures from one position, I took a set from six different positions. Each photo looks directly at the wall. I moved from one end to the other. Carefully staying the same distance from the wall. Here is my set:

LJK_2269 (3872x2592) (100x67)LJK_2270 (3872x2592) (100x67)LJK_2271 (3872x2592) (100x67)LJK_2272 (3872x2592) (100x67)LJK_2273 (3872x2592) (100x67)LJK_2274 (3872x2592) (100x67)

Doing this is a bit tricky. Do not use a wide-angle lens setting. The best results are obtained when you are as far from the subject as possible. If you are very careful, and the subject is quite flat, the pictures can be stitched nicely. See, I didn’t use the street, I used a wall! I am never all that careful and my resulting panorama has some flaws, but it is not bad:

LJK_2269 (3872x2592)_stitch_thumb

Now it looks like the wall that it really is. This was done using Image Composite Editor with the StitchCamera motion control set to Planar Motion 3. The default setting is Rotating Motion – for the “normal” panoramas that are taken from one point.

If you have not already discovered the links, each of the panoramas above can be seen larger by clicking on the images. The tool for that is “Zoom.it” – and that is another story.

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