Happy to share VB .NET code to encrypt/decrypt the image. Use some tool to split an image into pieces. Image encryption code:
Public Function EncryptStream(ByVal input As Byte()) As Byte()
Dim rijn As New RijndaelManaged()
Dim encrypted As Byte()
Dim key As Byte() = New Byte() {&H22, &HC0, &H6D, &HCB, &H23, &HA6, _
&H3, &H1B, &H5A, &H1D, &HD3, &H9F, _
&H85, &HD, &HC1, &H72, &HED, &HF4, _
&H54, &HE6, &HBA, &H65, &HC, &H22, _
&H62, &HBE, &HF3, &HEC, &H14, &H81, _
&HA8, &HA}
Dim IV As Byte() = New Byte() {&H43, &HB1, &H93, &HB, &H1A, &H87, _
&H52, &H62, &HFB, &H8, &HD, &HC0, _
&HCA, &H40, &HC2, &HDB}
Dim encryptor As ICryptoTransform = rijn.CreateEncryptor(key, IV)
Dim msEncrypt As New MemoryStream()
Dim csEncrypt As New CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write)
csEncrypt.Write(input, 0, input.Length)
csEncrypt.FlushFinalBlock()
encrypted = msEncrypt.ToArray()
Return encrypted
End Function
Decryption code:
Public Function DecryptStream(ByVal input As Byte()) As Byte()
Dim rijn As New RijndaelManaged()
Dim decrypted As Byte()
Dim key As Byte() = New Byte() {&H22, &HC0, &H6D, &HCB, &H23, &HA6, _
&H3, &H1B, &H5A, &H1D, &HD3, &H9F, _
&H85, &HD, &HC1, &H72, &HED, &HF4, _
&H54, &HE6, &HBA, &H65, &HC, &H22, _
&H62, &HBE, &HF3, &HEC, &H14, &H81, _
&HA8, &HA}
Dim IV As Byte() = New Byte() {&H43, &HB1, &H93, &HB, &H1A, &H87, _
&H52, &H62, &HFB, &H8, &HD, &HC0, _
&HCA, &H40, &HC2, &HDB}
Dim decryptor As ICryptoTransform = rijn.CreateDecryptor(key, IV)
Dim msDecrypt As New MemoryStream(input)
Dim csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
decrypted = New Byte(input.Length - 1) {}
csDecrypt.Read(decrypted, 0, decrypted.Length)
Return decrypted
End Function