This book constitutes the thoroughly refereed post-conference proceedingsof the 4th International Conference on Pattern Recognition, ICPRAM 2015,held in Lisbon, Portugal, in January 2015. The 20 revised full papers were carefully reviewed and selectedfrom 145 submissions and describe up-to-date applications of patternrecognition techniques to real-world problems, interdisciplinaryresearch, experimental and/or theoretical studies yielding new insightsthat advance pattern recognition methods.