Jpegtran is CUI tool developed by IJG(Independent JPEG Group).
This software is Jpegtran ported to Android.
Jpegtran can perform the following operations without quality loss.
- Rotation in 90 degree units (-rotate)
- Make grayscale image (Drop color components) (- grayscale)
- Flipping horizontal / verticval / XY axes (-flip, -transpose, -transverse)
- Cut out part of image (-crop)
- Partial fill of image (-wipe)
- Optimization of Huffman table (-optimize)
- Conversion to progressive JPEG (-progressive)
- Add restart marker (-restart)
How to use
- Tap [Input]. Since the gallery opens, choose a JPEG image.
- Tap [Switch] to select the operation to be performed on the JPEG image.
- The output file name automatically generated and displayed to [Output].
If you want to change, tap [Output].
- Press the [Execute] button
- When OK is displayed in [Result], processing is finished.
By tapping [Result], you can check the result.
Crop and Wipe
The area of Crop and Wipe can be specified while watching the image.
Choose [Switch] -> [Transform] -> [AreaSelector].
An image is displayed and a white line is displayed at the boundary.
Drag this white line and specify the area.
Image information can be displayed by long tapping.
Press Menu key, or press three dots on title bar, menu will be displayed.
- Input selector
You can choose to use the gallery to select images or use the built-in file selector.
- Default output
You can select how to automatically generate filenames.
File name appended with "_ajt" in the same directory.
Save to specified directory.
To long tap [Input], you can check the source JPEG image.
Example of operation
Here is an example of the operation to cut out part of an image.
- Tap [Input] and select an image
- Choose [Switch] -> [Entropy coding] -> [-optimize]
You can reduce the file size with this operation.
- Select [Switch] -> [Transform] -> [TransformType] -> [Crop]
- Select [Switch] -> [Transform] -> [TransformType] -> [AareSelector]
As the image is displayed, drag the white frame to make the area of the image.
- Tap [Executte] to execute "Jpegtran"
- Tap [Result] and check the result image.
About this software
This software is based on part on the work of the Independent JPEG Group.