AutoStitch: an iPhone panorama alternative for power photographers
Mac Tip #554, 03 October 2012
Panorama mode, introduced to the iPhone in iOS 6, produces surprisingly high quality photo results and is rather simple to use. Yet, in true Apple style, the feature has something of a one-size-fits-all sort of mentality. AutoStitch’s enhanced features and flexibility though make it a pro tool for panoramas, as guest author Lee Bennett explains.
Lee Bennett is a native Floridian who works near Orlando in the fields of print layout design, audio/video media and production, web content, and photography.
The built-in Panorama mode
By way of a quick review (see Make panoramas with iPhone and iOS 6), panorama mode in iOS 6 works by enabling it from the
Options button in the Camera app and slowly/steadily panning across the desired panorama. [Screenshot on Page 2]
More than one source has claimed that the feature only works with the iPhone in the upright position and you can only pan left to right. The reality is, you can instead pan right to left if you turn the phone upside down. You can also take vertical panoramas, panning top to bottom or bottom to top, by turning the phone 90 degrees in the appropriate direction. Just follow the arrow on the screen.
Miraz notes: Lee supplied lots of excellent quality very large photos and screenshots for this Tip. I’ve had to reduce both size and quality considerably otherwise this web page would never load. I take the blame for any images that look bad. Some photos and screenshots appear on Page 2.
Scan for panorama is clumsy
For me, this scanning method of taking panoramas has always seemed clumsy, even when I’ve tried the equivalent feature that some digital cameras have introduced in recent years.
It can be tricky to keep the device level, although iOS has a very good indicator to help you stay in line.
Perhaps more frustrating has been when someone or something moved into the foreground as I was panning across, forcing me to cancel the shot and start over.
AutoStitch Panorama is for serious panorama shots
Enter the AutoStitch Panorama app by Cloudburst Research. At just US$2, this is the go-to app for anyone serious about panorama photos with their iPhone.
In AutoStitch Panorama, the user begins with the choice to shoot a panorama directly within the app, select photos already saved on the iPhone to create a panorama, or browse previously saved panoramas. [Screenshot on Page 2]
Although you can shoot photos to be stitched together from any app you wish, the new augmented reality feature is a compelling reason to always shoot the panorama segments within the AutoStitch app.
Augmented reality helps line up the shots
Augmented reality shows where each photo segment has already been taken, helping you confirm that you’ve covered the entire area you wish to include in the panorama. [Screenshot on Page 2]
The blue-shaded rectangles indicate the shots you’ve taken, and they stay in place relative to the scene as you move the phone around.
While shooting, the outer border and the shutter button turn green when your phone is ideally aligned relative to previous shots, yellow if the framing is questionable whether it can be stitched, and red if the framing definitely can’t be matched up to earlier shots.
A flexible approach
There are two real strengths of shooting panoramas this way:
1. You don’t have to think wide or tall. It may be more accurate to think in terms of a collage. AutoStitch is perfectly capable of creating a large, square image stitched from a grouping of photos, such as the 4×2 grouping shown in the app’s main menu.
2. You can take as long as you need to snap each segment. If I’ve shot the first three of a four-wide panorama, and someone steps into the frame where I’m about to shoot the fourth image, I can wait for them to move out of the way before completing the shot.
Stitching and rendering
When you begin stitching a panorama, AutoStitch will first evaluate all the frames and let you know how many of them were able to be used.
Boxed segments progressively flip to a portion of the panorama as the images are processed. [Screenshot on Page 2]
The amount of time necessary to render a panorama depends on many factors. First of all, I noticed a significant speed improvement when I upgraded from an iPhone 4 to a 4S. I strongly suspect the iPhone 5 will render AutoStitch panoramas even faster still.
The other factors for rendering time depend on how well aligned the frames are, the number of total frames, and the quality settings chosen. I’ll confess to being a resolution junkie and am willing to wait for a rendering using the maximum settings in all areas. Even with the settings maxed, the five-shot panorama example in this MacTip took little more than a minute to stitch.
Choose settings to match your needs
Unless you’re commonly very crunched for time, using “Best” Blending and Auto-Exposure turned on is advised. [Screenshot on Page 2]
Besides the “Low,” “Standard,” and “High” Resolution presets, the “Advanced” setting allows customization.
The Resolution screen will reveal what percentage and maximum size will be used, which could be replicated in the “Advanced” setting. [Screenshot on Page 2]
Cropping the panorama.
Once rendering is complete, you then have the opportunity to crop the image.
By default, the “Auto” selection is made which, like iOS panoramas, attempts to provide the maximum amount of image with no black borders. However, the advantage goes to AutoStitch for not only allowing you to crop even tighter, but also to not crop at all if you absolutely want every pixel you originally shot and don’t mind the angled and curved edges caused by morphing the frames into the final shot.
The finished AutoStitch panorama.
Unlike iOS panoramas, AutoStitch avails the source photos that can be saved to your Camera Roll, if desired. [Screenshot on Page 2]
AutoStitch panoramas are saved within the app and can be re-stitched with different settings at any time. This is a great way to compare the Resolution presets on the exact same panorama. [Screenshot on Page 2]
The comparison between AutoStitch and the built-in Panorama feature
So how do AutoStitch panoramas compare to iOS panoramas?
Miraz says: the two images below are resized and optimised to keep their ‘weight’ small. Download the images at full size and resolution in a zipped file so you can look at their full glory on your own computer: panoramas-compared-Lee-Bennett-MacTips.zip (7.3 MB zipped file).
In an effort to remove as many variables as possible for a comparison, before shooting each panorama, I tapped and held on the same spot (the two black cars in the foreground) to hopefully make the exposure and white balance as identical as possible.
To my eye, the exposure appears to match, but the iOS image has better white balance. I feel certain this was just the result of a subtle variation of lighting or not tapping on exactly the same pixel for exposure lock. The white balance of these photos could, quite possibly, have been reversed when they were shot. If necessary, I can very easily correct this in an image editor.
Possibly a bit more difficult to fix is that the iOS panorama appears to have an unnatural aspect ratio. Car wheels seem to be somewhat oval (squished horizontally). The AutoStitch panorama has a more natural-looking ratio.
A possible advantage for iOS panoramas is the amount of JPG compression applied. The iOS image is 9.8 megabytes and the AutoStitch image is 3.2 megabytes. Yet, both images are very close to the same pixel size (a little more than 6,100 pixels wide and approximately 2,400 pixels tall). To me, this translates to heavier compression being used by AutoStitch.
An expert may be able to see heavier JPG artifacts in the AutoStitch image, but to my eye, I see no degradation that concerns me. The advantages described in this MacTip more than make up for for the possibility of a slightly heavier JPG compression.
Yes, I will occasionally use the iOS tool if I need a panorama in a hurry, especially with Apple’s Camera app quick access from the iPhone lock screen. But AutoStitch’s enhanced features and flexibility make it my primary tool for panoramas.
See the next page for more screenshots and photos.