Image stitching - the term is actually a good analogy. Stitching images or photos is the process of combining several digital images together so that you get one big one in the end.
That wouldn't be so tough you might say, but what makes stitching software so helpful is that it is "sewing" those photographs together with no obvious trace of the seam. What you get is a great single panorama view of what you have photographed with several pictures.
Go straight to the Quick Selection Guide
Microsoft Image Composite Editor (abbreviated as ICE) - I am very, very impressed with this photographic image stitcher. Started as a BETA, this great software by Microsoft has developed immensely and is still free! The first thing you have to have of course is some pics to stitch together and I have tried a number of different images from 2 to 8 the stitching of the images worked very well on all the panoramic pictures, whether it was vertical or horizontal. Opening formats it accepts JPG, BMP, TIFF, PNG and HD Photo image.
There are four modes of camera motion to stitch your sequence of images, three fixed and one that you can adjust the distortion and that the 'Rotation motion'. When in this mode just click the 3D icon on the top taskbar, where you can tilt, zoom in and out. When you are happy with your construction then you can leave the cropping to another imaging software or auto crop. The finished panoramic image is exported into JPG, BMP, TIFF, PNG, HD Photo image, Adobe Photoshop, HD View Tileset and Deep Zoom Tileset.
As an added bonus .psd you can export in layers! Any other alterations can be achieved in your image software. The project can be saved as a .spi file enabling quick access if you so wish to return and alter the image again. I have read on several sites that the Fisheyed lens shots are not quite successful, but for most of us it does the job extremely well. If you have a Fisheye lens it would be great to inform us how you get on with it.
Autostitch - a program written by Matthew Brown, a PhD student at the University of British Columbia. It comes complete with some sample pictures for you to play with. Select File/Open and choose your pictures, and then just sit back and wait while it formats the photos into a single combined panorama. All lighting corrections and blending are done for you. The downside of this program is some arcing in the panorama that leaves black edges. You will need to crop the panorama to get clean edges.
Windows Live Photo Gallery - which is an allrounder for managing your photos (much the same as Picasa), but a little-publicised feature is available in the Make menu: "Panorama Stitcher". It is a no-brainer - simply select the photos from the thumbnails viewer, and the program does the rest. Cropping and adjustment is immediately at hand under the Fix menu. The program works much like Autostitch. The blending results, incidentally, are superior as compared to purchased programs such as Adobe Photoshop Elements. Highly recommended all around.
Panorama Perfect Lite - It's the freeware version of a commercial product, but the only difference I can see is a limitation on the size of the panorama picture it can produce. However, this should not be a constraint for most users.
The strength of this software is its ability to match up photos taken without a tripod. Using nodes on the blending area of each photo, you can match each structure (tree, building etc.) to ensure that there is no distortion when joining. Although more complex, this process allows a better stitch without the bending and distortion you sometimes get with Autostitch. This difference will not be important to casual photographers, but more serious users will consider the effort worthwhile.
HUGIN Panorama Photo Stitcher by Sourceforge.
Let us know here in the comments or in our forum if you know of any related free products that deserve mentioning here.
Microsoft Image Composite Editor
Windows Live Photo Gallery
Panorama Perfect Lite
image stitching lighting blending panorama ice image composite editor autostitch panorama perfect lite microsoft live photo gallery