What changed in ZXing from 2 to 3

What's Changed

• Fix container inefficiency in RSSExpandedReader.java by @cinsttool in https://github.com/zxing/zxing/pull/1782
• Fix SYMBOLOGY_IDENTIFIER Loss in QRCodeMultiReader to Ensure Data Integrity and Functional Consistency with QRCodeReader by @xiebaiyuan in https://github.com/zxing/zxing/pull/1839
• Be more stringent on email validation rules by @ftiercelin in https://github.com/zxing/zxing/pull/1870
• PDF417: Check that input is made of 0...127 chars when using Compaction.TEXT, throw an explicit exception if not the case by @ftiercelin in https://github.com/zxing/zxing/pull/1878
• Fixing issue #1831 by @ftiercelin in https://github.com/zxing/zxing/pull/1879
• Add hint to correct wrong dimension by @magethle in https://github.com/zxing/zxing/pull/1901
• Fix distortion calculation for isosceles right triangles by @magethle in https://github.com/zxing/zxing/pull/1908
• Add input validation for pixel array length in RGBLuminanceSource to avoid ArrayIndexOutOfBoundsException by @leofernandesmo in https://github.com/zxing/zxing/pull/1961
• Add 90-degree rotation support to RGBLuminanceSource by @gredler in https://github.com/zxing/zxing/pull/2012
• Add GrayscaleLuminanceSource by @gredler in https://github.com/zxing/zxing/pull/2013
• Loosen ITF max variance for 3x module widths by @gredler in https://github.com/zxing/zxing/pull/2014

Full Changelog: https://github.com/zxing/zxing/compare/zxing-3.5.3...zxing-3.5.4

What's Changed

• Fix MaxiCode handling of vertical quiet zone by @gredler in https://github.com/zxing/zxing/pull/1671
• Removing the forced content limit check for Code128Writer.java by @himanshushukla254 in https://github.com/zxing/zxing/pull/1675
• Detect RSS Expanded finder pattern false positives by checking sequences by @gredler in https://github.com/zxing/zxing/pull/1680
• Update GS1 AIs according to 2023 specification by @gredler in https://github.com/zxing/zxing/pull/1681
• Prevent --raw CLR option from failing if result.getRawBytes() is null by @dlenski in https://github.com/zxing/zxing/pull/1683
• Avoid 2 more RSS Expanded finder pattern false positive scenarios by @gredler in https://github.com/zxing/zxing/pull/1692
• Avoid decoding stacked row 1 of N independently by @gredler in https://github.com/zxing/zxing/pull/1693
• Support for platforms where SJIS is unavailable by @blakepuhak in https://github.com/zxing/zxing/pull/1747

New Contributors

• @himanshushukla254 made their first contribution in https://github.com/zxing/zxing/pull/1675
• @blakepuhak made their first contribution in https://github.com/zxing/zxing/pull/1747

Full Changelog: https://github.com/zxing/zxing/compare/zxing-3.5.2...zxing-3.5.3

• Minor enhancements for Code 128 and PDF417
• Restore compatibility with older JDKs See https://github.com/zxing/zxing/milestone/15?closed=1

• Various minor bug fixes, including more from oss-fuzz
• Avoid very long detection of QR codes in two types of pathological cases
• Don't fail QR code decoding if GB2312 not supported by JDK

See https://github.com/zxing/zxing/milestone/14?closed=1

• Many edge-case fixes and improvements from oss-fuzz
• Various improvements and fixes to Aztec, PDF417, DataMatrix decoding
• New 'minimal' encoding mode from @AlexGeller1 (https://github.com/zxing/zxing/issues/1444)

See https://github.com/zxing/zxing/milestone/13?closed=1

• Wifi QR codes now recognize PH2:, not H:, for phase 2 method
• Minor bug fixes and improvements

See https://github.com/zxing/zxing/milestone/12?closed=1

• Requires Java 8+. Note: Android apps using this version must target API 24 or higher.
• core, javase modules declare a Java 9+ module
• HtmlAssetTranslator and StringsResourceTranslator legacy utilities are moved to a .client.j2se subpackage
• No more releases of the Barcode Scanner app
• Minor bug fixes to Code93Writer
• Minor improvements to QR code detection

• Minor fixes and improvements
• Java 9+ support

https://github.com/zxing/zxing/milestone/11?closed=1

• Add workaround for Gradle + Android build issues
• Minor DataMatrix bug fixes
• Improve WPA2 wi-fi configuration support in Barcode Scanner
• Various translation updates and minor improvements

https://github.com/zxing/zxing/milestone/10?closed=1

• Various fixes to Code 128, 39 encoding; DataMatrix decoding
• Improvements to speed and robustness of zxing.org decoder
• Java 9 support
• Various translation updates for Barcode Scanner
• Removed Google Glass, ZXing Test apps
• Barcode Scanner 4.7.7
• Note: core library will require Android SDK 19+ when used in an Android app

https://github.com/zxing/zxing/issues?q=is%3Aclosed+milestone%3A3.3.1

• Minor core API additions like Result.getNumBits, raw bytes for Aztec
• Small changes for Java 9 compatibility
• Barcode Scanner 4.7.6 release with Android API 23 support
• TIFF support in online decoder
• Many small bug fixes, typo fixes and project build improvements

https://github.com/zxing/zxing/issues?q=is%3Aclosed+milestone%3A3.3.0

• Small bug fixes

https://github.com/zxing/zxing/issues?q=is%3Aclosed+milestone%3A3.2.1

• Several bug fixes, especially for Data Matrix and PDF417 parsing
• Retired jruby binding
• Barcode Scanner can now disable history

https://github.com/zxing/zxing/issues?q=is%3Aclosed+milestone%3A3.2.0

• Retire actionscript port
• Small bug fixes

https://github.com/zxing/zxing/issues?milestone=3&state=closed

• Several small bug fixes

https://github.com/zxing/zxing/issues?milestone=2&state=closed

• iphone/, cpp/, objc/, and glass-mirror/ are retired
• Java 7 now used for all Java-based modules
• Project moved to github.com/zxing/zxing
• Many small bug fixes and improvements