All the respondents (6) having zero or negative correlation coefficient were removed as outliers. Next, outliers were filtered out with the use of Spearman rank order correlation coefficient (SROCC) between single subject responses and averaged responses for the whole set. Z-scoring is computed as (where: i denotes user index, j denotes image index): Then, in order to compensate personal bias, the raw responses were standardized using z-scores per person and then re-scaled backward to 1 to 5 scale. ![]() The questionnaire form allowed to collect 191 answers from different countries. The users were requested to evaluate the visibility of a hidden animal with a numerical scale from 1 to 5, where ends of the scale were described as ‘ animal is in plain sight‘ and ‘ what animal‘. The online survey was prepared using the Google forms. 3) into four categories – C 0 non-masking background (blue), C 1 masking background (green), C 2 masked foreground (black), C 3 non-masked foreground (red). Next, image segments were annotated ( Fig. 2), which were taken by independent photographers who marked these as good examples of camouflaged animals. Thanks to this a test pool was gathered, containing 76 photos ( Fig. They were selected in order to present various camouflage efficiency – from animals clearly visible to almost invisible. The images were taken from the Internet, selected using Google image search using the ‘ camouflaged animal ‘ keyword. In order to avoid personal bias, authors five fellow students were asked to collect a pool of camouflaged animals images and manually annotate its areas. Since the topic is quite novel, it was necessary to perform some fundamental steps such as obtaining the ground truth a database of camouflaged animals which are then manually annotated and evaluated by independent respondents. The database allows finding how well the saliency map suits to human perception of objects, or what is detector efficiency for the objects which are intended to be hidden in the scene. The camouflage techniques are within the scope of biological sciences which are then followed by humans in military applications which were notably developed since World War I, but that research is poorly disclosed to the public. zebra stripes) or behavioral strategies just clearly intended for hiding such as nocturnal or subterranean life activity. There are also other forms of camouflage which are not intended to hide an animal in a scene but to confuse the observer (e.g. Here, the term crypsis requires explanation, ‘it comprises all traits that reduce an animal’s risk of becoming detected when it is potentially perceivable to an observer’. These are crypsis, mimicry which can rely on vision, odor, sound and behavior. They are intended to delay or even avoid observation or detection by other animals. Skurowski, submitted for publication, entitled: ‘ Relevance of saliency maps to the human perception for images of camouflaged animals‘.Ĭamouflage strategies in nature are evolutionarily developed concealment techniques for survival in both predator and prey species. The following description contains some excerpts from an article manuscript by P. ![]() The database was crafted by the team of students (in alphabetical order): Hassan Abdulameer, Jakub Błaszczyk, Tomasz Depta, Adam Kornacki, Przemysław Kozieł. This work was led by Przemysław Skurowski. Look through the photos above to see if these animals' disguises fool you.Animal Camouflage Analysis: CHAMELEON Database C.H.A.M.E.L.E.ON – Cryptic Hidden Animals Masked in Environment, Labelled and Evaluated (- ON) ![]() Some predators such as vipers and bobcats blend into their surroundings, allowing them to more effectively sneak up on their prey. ( Read more about the study.)Ĭamouflage is also effective for more than avoiding the hungry eyes of predators. One study published in 2014 suggested that, with the arrival of the first birds and mammals, insects quickly began to mimic plants as a form of survival. The walking sticks’ longtime disguises are a matter of survival. Few animals are more talented mimics than walking sticks, which have disguised themselves as twigs and leaves for the past 126 million years. Many animals also use mimicry, a form of camouflage that entails acting like another object or organism. ( Find out what happens when chameleons look in a mirror.) Chameleons, perhaps nature’s most famous masters of disguise, can change the color of their skin, in part to match their surroundings. Animals such as bobcats conceal themselves in tall grass the white fur of the arctic fox renders it virtually invisible against a snow-covered backdrop. While some animals defend themselves with sharp claw and powerful bites, others prefer a subtler approach to self-preservation.Īnimals all around the world in diverse environments use the visual technique of camouflage.
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