what exactly is the actual image data inside IDAT chunck in PNG file?

algorithm compression png

It says exactly what's in there in the specification you linked. Did you consider reading the specification?

Related

Cuda: error C2065:"threadIdx':undeclared identifier
Mysql replace all special unicode characters with their ascii counterpart
How to efficiently export 3 million documents from MongoDB Atlas collection to CSV file using NodeJS
Multi-source in Unit <###> on signal <###>; this signal is connected to multiple drivers [duplicate]
How to remove github login popup asking for credentials?
Error:identifer "blockIdx" is undefined
how do you pull data from json using jsonpath syntax
Room persistent library reset version to 1
How to use method referencing for a private method in same class
Image failed to align vertically inside td
Unable to detect Canvas tag inside ngfor iteration - Angular
Trouble Deleting in React Native Firebase Firestore