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GP-based Image Segmentation (GPIS) with Applications to Biomedical Image Segmentation. Problem statement. How do we select an optimal sequence of low-level image operators (& parameters) to get the segmented image?. Segmentation example: cell nuclei. …. Model description.
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GP-based Image Segmentation (GPIS) withApplications to Biomedical Image Segmentation (c) Louis Charbonneau and Nawwaf Kharma, 2009
Problem statement • How do we select an optimal sequence of low-level image operators (& parameters) to get the segmented image? (c) Louis Charbonneau and Nawwaf Kharma, 2009
Segmentation example: cell nuclei (c) Louis Charbonneau and Nawwaf Kharma, 2009
… (c) Louis Charbonneau and Nawwaf Kharma, 2009
Model description • We use Cartesian GP: • Primitive operators are clearly defined, their right combination is the problem • CGP allows for an easy interpretation of the resulting sequence • Segmentation is a class of problems without one perfect solution; CGP can handle this (c) Louis Charbonneau and Nawwaf Kharma, 2009
System objectives • Effectiveness: segmentation should be correct • Efficiency: The smallest number of operations • Transparency: operation sequences should be easy to understand (c) Louis Charbonneau and Nawwaf Kharma, 2009
System objectives (cont.) • Segmentation should be doable without a priori information (except for training ground truths) • Generality: effective on wide classes of images • Ease of Use: Minimal human intervention (c) Louis Charbonneau and Nawwaf Kharma, 2009
Fitness criterion (c) Louis Charbonneau and Nawwaf Kharma, 2009
Fitness criterion (c) Louis Charbonneau and Nawwaf Kharma, 2009
Fitness criterion (c) Louis Charbonneau and Nawwaf Kharma, 2009
Crossover (c) Louis Charbonneau and Nawwaf Kharma, 2009
Mutations (I) (c) Louis Charbonneau and Nawwaf Kharma, 2009
Mutations (II) (c) Louis Charbonneau and Nawwaf Kharma, 2009
Data 1026 images, 512 x 384 pixels 120 images, 340 x 780 pixels (c) Louis Charbonneau and Nawwaf Kharma, 2009
System settings, database 1 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Pixel segmentation accuracy, database 1 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Cell segmentation accuracy, database 1 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Statistical results, database 1 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Example of evolved program, database 1 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Example of evolved program, database 1 (c) Louis Charbonneau and Nawwaf Kharma, 2009
System settings, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Pixel segmentation accuracy, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Cell segmentation accuracy, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Statistical results, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Example of evolved program, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Intermediate steps of evolved program, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Intermediate steps of evolved program, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Intermediate steps of evolved program, database 2 (c) Louis Charbonneau and Nawwaf Kharma, 2009
Superimposed input + evolved program (c) Louis Charbonneau and Nawwaf Kharma, 2009
GPIS on other types of images tree detection Lane detection (c) Louis Charbonneau and Nawwaf Kharma, 2009
GPIS on other types of images Intra-cellular content of Wright-stained white blood cell images (c) Louis Charbonneau and Nawwaf Kharma, 2009
Conclusion • CGP was able to adapt to the complexity of input images: • A short program was evolved to solve the easy problem • a longer program was evolved to solve the harder problem • Operator pool can be extended with specialized operators • Injection was a reliable means of maintaining population diversity (c) Louis Charbonneau and Nawwaf Kharma, 2009
Conclusion • A training window approach is very effective for operator refinement • A small but accurate set of ground truths is enough to evolve segmentation algorithms without a priori information on the images (c) Louis Charbonneau and Nawwaf Kharma, 2009