| Some utilities for reading, writing, and color-coding .flo images |
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| Daniel Scharstein, 7/2/07 |
| updated 2/9/08 to fix bug in color_flow.cpp |
| updated 6/9/09 to make robust to NaN or constant 0 flow (thanks Jan Bouecke) |
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| See flowIO.cpp for sample code for reading and writing .flo files. |
| Here's an excerpt from this file describing the flow file format: |
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| // ".flo" file format used for optical flow evaluation |
| // |
| // Stores 2-band float image for horizontal (u) and vertical (v) flow components. |
| // Floats are stored in little-endian order. |
| // A flow value is considered "unknown" if either |u| or |v| is greater than 1e9. |
| // |
| // bytes contents |
| // |
| // 0-3 tag: "PIEH" in ASCII, which in little endian happens to be the float 202021.25 |
| // (just a sanity check that floats are represented correctly) |
| // 4-7 width as an integer |
| // 8-11 height as an integer |
| // 12-end data (width*height*2*4 bytes total) |
| // the float values for u and v, interleaved, in row order, i.e., |
| // u[row0,col0], v[row0,col0], u[row0,col1], v[row0,col1], ... |
| // |
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| Once you have a .flo file, you can create a color coding of it using |
| color_flow |
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| Use colortest to visualize the encoding |
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| To compile |
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| cd imageLib |
| make |
| cd .. |
| make |
| ./colortest 10 colors.png |
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