Must validate images present on the page

I have a specific URL example https://www.gnostice.com/nl_article.asp?id=207&t=How_To_Read_A_PDF_File_From_A_URL_In_Java (images present in URL not in any folder locations)

Requirements of Image specifications to validate:

1. 5-inch width = 672
2. 7-inch width = 840

I have 27 available <img and have to check:

1. how many images are 5-inch width = 672
2. how many images are 7-inch width = 840
3. is there are any images with other dimensions

Could you please tell me how can I validate it using java selenium... thank you