TranJPEG

TranJPEG is a WIMP front-end for the IJPG command-line utility 'jpegtran' and gives easy access to the features of the utility. It allows JPEG images to be transformed in a number of ways in a lossless process.

The transformations include rotation, reflection, smart scaling and transposing images. There is also an AUTO rotate option, which depends on the image containing exif data with orientation information.

TranJPEG allows a selection of images to be transformed in a batch process that occurs in the background.

TranJPEG has been tested successfully on the IGEPv5 based RapidO Ig, the Titanium and the iMX6. It should also run on BeagleBoard, PandaBoard and Raspberry Pi hardware.

You can download the TranJPEG application (complete with in app help file, in html format) as a zip file. TranJPEG includes the jpegtran binary (version 9d, 12 Jan 2020).

Download TranJPEG, Version: 1.36 (14 Jan 2022), Zip file size: 255 KB

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Source code

The source code to TranJPEG is now provided. This is supplied in a format that should compile. It must be linked with David Pilling's TaskLib library. David has released the sources to many of his applications, which can be found here. The source to TaskLib itself can be found on David's site. However, since the version I use probably has some differences and additions, my version of TaskLib is provided here prebuilt and with source code.

Download TranJPEG source code, Version: 1.36 (14 Jan 2022), Zip file size: 47 KB

Download TaskLib prebuilt and source code, Zip file size: 275 KB

Note that changes to code that does not materially alter a feature may not be listed here.

Changes in 1.36

• Settings/choices dbox can now be opened also from iconbar icon right click or iconbar icon menu (only from process dbox before)
• Now uses jpegtran binary based on IJPG library version 9d (12 Jan 2020)

Changes in 1.35

• Squashed a null pointer dereference that could be produced when a directory of jpegs were auto-rotated, but there was nothing to do

Changes in 1.34

• Improved exif header parsing (needed for auto-rotate) to cope with non-standard metadata

Changes in 1.33

• Added processing option 'overwrite original file'
• Added status process completed message for auto rotate files
• Bugfix: Smartscale not giving correct scale factor

Changes in 1.32

• Added the option 'Crop image'

Changes in 1.31

• Added option 'Strip EXIF data'
• Added setting 'Keep original timestamp'
• Bugfix - transforming very small files could cause a hang
• Updated the jpegtran binary to version 9a
• Other small bug fixes

Changes in 1.30

• Added progressive option
• Added optimise option
• Added greyscale option
• Configuration now saved in Boot-Choices rather than application directory

Changes in 1.20

• Added the SmartScale transformation. Note that not all RISC OS software that loads or displays jpeg images currently understands SmartScaled images
• Updated the jpegtran binary to version 9, 13 Jan 2013

All communication about TranJPEG should be directed to Chris Johnson (chrisjohnson@spamcop.net ). Suggestions for new features are always welcome.