85,234 research outputs found
Common Limitations of Image Processing Metrics:A Picture Story
While the importance of automatic image analysis is continuously increasing,
recent meta-research revealed major flaws with respect to algorithm validation.
Performance metrics are particularly key for meaningful, objective, and
transparent performance assessment and validation of the used automatic
algorithms, but relatively little attention has been given to the practical
pitfalls when using specific metrics for a given image analysis task. These are
typically related to (1) the disregard of inherent metric properties, such as
the behaviour in the presence of class imbalance or small target structures,
(2) the disregard of inherent data set properties, such as the non-independence
of the test cases, and (3) the disregard of the actual biomedical domain
interest that the metrics should reflect. This living dynamically document has
the purpose to illustrate important limitations of performance metrics commonly
applied in the field of image analysis. In this context, it focuses on
biomedical image analysis problems that can be phrased as image-level
classification, semantic segmentation, instance segmentation, or object
detection task. The current version is based on a Delphi process on metrics
conducted by an international consortium of image analysis experts from more
than 60 institutions worldwide.Comment: This is a dynamic paper on limitations of commonly used metrics. The
current version discusses metrics for image-level classification, semantic
segmentation, object detection and instance segmentation. For missing use
cases, comments or questions, please contact [email protected] or
[email protected]. Substantial contributions to this document will be
acknowledged with a co-authorshi
Learning of Image Dehazing Models for Segmentation Tasks
To evaluate their performance, existing dehazing approaches generally rely on
distance measures between the generated image and its corresponding ground
truth. Despite its ability to produce visually good images, using pixel-based
or even perceptual metrics do not guarantee, in general, that the produced
image is fit for being used as input for low-level computer vision tasks such
as segmentation. To overcome this weakness, we are proposing a novel end-to-end
approach for image dehazing, fit for being used as input to an image
segmentation procedure, while maintaining the visual quality of the generated
images. Inspired by the success of Generative Adversarial Networks (GAN), we
propose to optimize the generator by introducing a discriminator network and a
loss function that evaluates segmentation quality of dehazed images. In
addition, we make use of a supplementary loss function that verifies that the
visual and the perceptual quality of the generated image are preserved in hazy
conditions. Results obtained using the proposed technique are appealing, with a
favorable comparison to state-of-the-art approaches when considering the
performance of segmentation algorithms on the hazy images.Comment: Accepted in EUSIPCO 201
Panoptic Segmentation
We propose and study a task we name panoptic segmentation (PS). Panoptic
segmentation unifies the typically distinct tasks of semantic segmentation
(assign a class label to each pixel) and instance segmentation (detect and
segment each object instance). The proposed task requires generating a coherent
scene segmentation that is rich and complete, an important step toward
real-world vision systems. While early work in computer vision addressed
related image/scene parsing tasks, these are not currently popular, possibly
due to lack of appropriate metrics or associated recognition challenges. To
address this, we propose a novel panoptic quality (PQ) metric that captures
performance for all classes (stuff and things) in an interpretable and unified
manner. Using the proposed metric, we perform a rigorous study of both human
and machine performance for PS on three existing datasets, revealing
interesting insights about the task. The aim of our work is to revive the
interest of the community in a more unified view of image segmentation.Comment: accepted to CVPR 201
Skin Colour Segmentation using Fintte Bivariate Pearsonian Type-IV a Mixture Model
The human computer interaction with respect to skin colour is an important area of research due to its ready applications in several areas like face recognition, surveillance, image retrievals, identification, gesture analysis, human tracking etc. For efficient skin colour segmentation statistical modeling is a prime desiderata. In general skin colour segment is done based on Gaussian mixture model. Due to the limitations on GMM like symmetric and mesokurtic nature the accuracy of the skin colour segmentation is affected. To improve the accuracy of the skin colour segmentation system, In this paper the skin colour is modeled by a finite bivariate Pearsonian type-IVa mixture distribution under HSI colour space of the image. The model parameters are estimated by EM algorithm. Using the Bayesian frame the segmentation algorithm is proposed. Through experimentation it is observed that the proposed skin colour segmentation algorithm perform better with respect to the segmentation quality metrics like PRI, GCE and VOI. The ROC curves plotted for the system also revealed that the developed algorithm segment pixels in the image more efficiently. Keywords: Skin colour segmentation, HSI colour space, Bivariate Pearson type IVa mixture model, Image segmentation metrics
Overview: Computer vision and machine learning for microstructural characterization and analysis
The characterization and analysis of microstructure is the foundation of
microstructural science, connecting the materials structure to its composition,
process history, and properties. Microstructural quantification traditionally
involves a human deciding a priori what to measure and then devising a
purpose-built method for doing so. However, recent advances in data science,
including computer vision (CV) and machine learning (ML) offer new approaches
to extracting information from microstructural images. This overview surveys CV
approaches to numerically encode the visual information contained in a
microstructural image, which then provides input to supervised or unsupervised
ML algorithms that find associations and trends in the high-dimensional image
representation. CV/ML systems for microstructural characterization and analysis
span the taxonomy of image analysis tasks, including image classification,
semantic segmentation, object detection, and instance segmentation. These tools
enable new approaches to microstructural analysis, including the development of
new, rich visual metrics and the discovery of
processing-microstructure-property relationships.Comment: submitted to Materials and Metallurgical Transactions
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