DataMatrixWriter/ECC200 and ReedSolomonEncoder

[Zorawar B.]

Hello,

My apologies in advance if I do not use the terminology correctly and have missed something obvious.

The wikipedia entry for Data Matrix codes, [1], says the newer version ECC200 uses Reed-Solomon codes. Going through the sources I saw that the DataMatrixWriter internally creates ECC200 error correction code, ErrorCorrection [2].

My questions are,
Q1. Is ErrorCorrection[2] internally also using the Reed-Solomon algorithm for creating the codes?
Q2. What is the purpose of ReedSolomonEncoder [3]?
Q3. Using zxing how should the error-code bytes be generated for the ReedSolomonEncoder?

[1]. https://en.wikipedia.org/wiki/Data_Matrix#Data_Matrix_ECC_200
[2]. https://zxing.github.io/zxing/apidocs/com/google/zxing/datamatrix/encoder/ErrorCorrection.html
[3]. https://zxing.github.io/zxing/apidocs/com/google/zxing/common/reedsolomon/ReedSolomonEncoder.html

Regards,
Zorawar

[Sean Owen]

My knowledge is also rusty and incomplete, but certainly the main version of Data Matrix uses Reed-Solomon, yes. That means it's needed for decoding and encoding too, if that's what you mean? you determine the EC bytes using Reed-Solomon and the implementation you point to. I'm not sure what you refer to besides this.