CryptoGraffiti.info litecoin alternative
I can't find much on writing data to the litecoin blockchain, you might need to code something yourself, perhaps taking the data you want to upload, chunk it and write it by using many transactions. To read it back you need to read these transactions from the blockchain and put the data chunks back together.

If I were you I would look into Ethereum instead. Ethereum has the ability to let you write customized smart contracts that can accept files/pictures data and store it forever on the Eth blockchain. If this gets too expensive you can offload storage using IPFS, so that the Eth blockchain would need to store only the hash of the files instead of the whole files.