Hello, there are a number of free and premium software for your fruit image analysis in the web. Please, check the following links and begin your quest:
https://www.researchgate.net/publication/304870946_Quant_poster_-_Ouro_Preto_Conference_2001 and https://www.researchgate.net/publication/229086201_Quant-A_software_to_quantify_plant_disease_severity
Data Quant poster - Ouro Preto Conference 2001
Conference Paper Quant-A software to quantify plant disease severity