Images

• pngcheck

  Check if a PNG file is valid. If it is not, displays the error.

• pngcsum - Website

  Correct the CRCs present in a PNG file.

• PNG Check & Repair Tool - GitHub

  Correct a corrupted PNG file.

  Utility to try and correct a PNG file.

  Need to press enter to show the file.

• Reading the specifications

  Reading the specification of image format are sometimes the only way to fix a corrupted image.

  File type	Summary	Full Specification
  PNG	Summary	Full Specification
  JPEG	Summary	Full Specification

Online tools

• Forensically

  Forensically is free online tool to analysis image this tool has many features like Magnifier, Clone Detection, Error Level analysis, Noise Analysis, level Sweep, Meta Data, Geo tags, Thumbnail Analysis , JPEG Analysis, Strings Extraction.