We designed two efficient and user-friendly tools for the segmentation and analysis of images containing chromosomes or, more generally, rod-shaped elements that are spread on microscopic slides. The segmentation tool allows to automatically extract the profile of each chromosome and to sort the collection of profiles in a karyotype image. The analysis tool is interactive and allows to extract quantitative measurements and annotate the relative position of the centromere to the chromosome extremities in a fast and reproducible way. The two methods rely on custom variants of parametric active contours. Both have been designed as user-friendly plug-ins for the open-source software ImageJ.