We have chewed long and we have chewed hard. Very hard, and the world’s first 1 trillion pixel macro image is done! Below are the detailed steps for post-processing the terabite image. And finally, on the second anniversary of photographing the food mosaic at SIGGraph, we are releasing the Terabite into the wild! Enjoy!
Chewing the Terabite - making a trillion pixel macro image
Step 1: Sort Files
Files are sorted and renamed to prepare them for focal stacking. The sorting takes serially numbered photographs and pivots the entire panel, organizing into folders for focal stacking, and handling the specific shooting pattern we used for the Terabite.
Software used: GIGAmacro Capture. Processing time: 20 minutes per panel, 21 hours total.
Step 2: Focal Stacking
Each focal stack comprises 6 photographs. The stacking process expands the total focal depth from 1mm to 5 mm in a single image by combining all six shots into one composite for each stack. “Where did the extra 1mm go?” you ask. Well 1mm was ‘lost’ as we overlap the images to ensure that sharpness is maintained throughout the composite photo.
Software used: Zerene Stacker. Processing time: 20 hours per panel / 1260 hours
Step 3: Create The Master Stitch Template
The master template places images in a grid format taking into account the overlap between images, shooting order. A focal length of 20,000mm is used to force the images to be placed in a nearly orthogonal planar space. Optimization settings are adjusted to allow for optimization of each panel but leaving the border rows and columns in place without any adjustments during optimization. These adjoining rows are merged in a different process before being merged back into the final image,
Software used: PTGui. Processing time: 4 hours
Step 4: Stitch Images (generate control points)
Control points are generated to match features between images. An estimated 10 million control points were generated. AutopanoGiga is used because of the very high quality of stitching it can do. However, optimization and rendering is handled using PT Gui in later steps. Project files are saved in panotools format.
Software used: AutopanoGiga. Processing time: 2 hours per panel / 126 hours
Step 5: Stitch Images – merge control points with template
Control points are extracted from the panotools file and merged with the master template for each panel.
Software used: Text Editing (Wordpad). Processing time: 10.5 hours
Step 6: Stitch Images – optimize stitched image
Optimize control points for each panel in PTGui. Optimization uses the control point data to find the best fit for all of the images in each panel. Specific optimization settings are used to keep the borders of each panel oriented correctly while allowing the overall image to be aligned precisely.
Software used: PTGui. Processing time: 1 hour per panel / 63 hours
Step 7: Stitch Images – render each panel
Render each panel into PSB format.
Software used: PTGui Processing time: 2 hours per panel / 126 hours
Step 8: Split Panels into Sections
Each of the 63 panels is split into 25 individual sections. This allows for more efficient editing of the panorama in Photoshop.
Software used: Krpano Tools. Processing time: approx. 3 hours per panel / 181 hours
Step 9: Merge Panel Borders in Photoshop & Cleanup
Borders between each panel are merged in Photoshop manually. Minor cleanup of seams and poorly stitched areas.
Software used: Photoshop. Processing time: 82 hours
Step 10: Recombine Sections
All sections are recombined to create the final single terapixel image.
Software used: Krpano. Processing time: 253 hours
Step 11: Convert to Tiled Image Format
Convert the full image to a tiled image format (Open Street Maps format)
Software used: Krpano. Processing time: 75 hours
And all of this – effectively a person year of effort – had to be achieved in spare hours whilst we run the business! You can perhaps start to see why this has been long project!