What does it do? 

This extension automatically resizes images to a given maximum height/width or total image size right after they have been uploaded to the TYPO3 website. The aspect ratio is of course kept.

The idea behind this extension is that TYPO3 should make both administrators and editors happy. Administrators want the website's footprint on server as small as possible to be able to handle backups efficiently and want the web server to deliver the pages as quick as possible. On the other hand, editors should be able to do their job and not bother with technical considerations such as the size of a picture on disk or that uploading their wonderful sunset taken during holidays with their 12 MP camera will slow down the time rendering of their great photo gallery where pictures are shown with a maximum definition of 800 × 600 pixels. Moreover, editors are either not aware of this or are simply unable to "prepare" their pictures as they are using a foreign computer (in a cyber café) or on the road with their laptop, neither of them running their beloved image editing software.

General configuration settings let you choose which directories should be somehow "monitored" for uploaded pictures and define the file types that should be handled (e.g., "jpg" and "tif" but not "png" nor "gif") and a file size threshold (e.g., "skip any picture smaller than 400 KB"). After all, if an editor managed to create a picture of many mega-pixels that weights only a few KB, why should we bother?

Screenshots 

Configuration settings 

The following two figures Configuration settings and Configuration settings show how an administrator may easily configure rules to resize uploaded images.

Screencast 

The team from jweiland.net prepared a screencast showing how to install and configure this extension in your TYPO3 website:

Thanks a lot for providing this online resource to the community.

Requirements 

In order to extract metadata while resizing images and automatically rotate images based on the EXIF information, those PHP methods should be available:

• exif_read_data;
• iptcparse.

Workflow 

Simply upload your unmodified pictures either from the File > Filelist module (fileadmin) or from the edit form of a content element (text with image, image, ...) and enjoy the automatic resizing and orientation in portrait of your pictures (here with an original picture in 3840 × 2560, 6.5 MB with EXIF orientation set to "portrait"):

As you see, the constraints of 1024 × 768 pixels have been taken into account even with the correct orientation of the picture. If the reorientation did not have been taken into account, the picture would have been resized to 682 × 1024 instead (maximum ratio using the other dimension).

Here is another example, where a BMP (screenshot.bmp, 15.7 MB, 2732 × 1920) has been uploaded:

The uploaded file screenshot.bmp has automatically been both resized and converted to a new file screenshot.jpg (according to the image type conversion mapping option described in chapter Administrator Manual).

Details of this image show that its footprint is now quite small (131.4 KB).

Supported image types 

This extension performs the resize with the standard image library API from TYPO3 meaning that on a well-configured system, following formats are supported:

ai

Adobe Illustrator

bmp

Windows OS/2 Bitmap Graphics

gif

Graphic Interchange Format

jpg/jpeg

JPEG/JIFF Image

pcx

Paintbrush Bitmap Graphic

png

Portable Network Graphic

tga

Truevision Targa Graphic

tif/tiff

Tagged Image Format

Directories 

This is a comma-separated list of directories that should be monitored for image uploads. This includes any subdirectory of them too. In the example above, 1:/ (corresponding to the well-known directory fileadmin/) will be monitored.

You may use two different wildcards characters:

• The single asterisk (*) searches for a single directory. E.g., 1:/*/images/ will match fileadmin/directory1/images/ and fileadmin/directory2/images/ but not fileadmin/directory3/subdirectory/images/.
• The double asterisk (**) searches for any number of subdirectories. E.g., 1:/**/images/ will match any subdirectory images within fileadmin, and of course any sub-subdirectory of it too.

File size threshold 

Only original pictures with file size bigger than this value will be processed. The field accepts suffices "B" for bytes, "K" for KB and "M" for MB. The number itself is interpreted as an integer.

Image types 

This is the list of image formats that should be processed, if both the directory and the size threshold match. The actual list of available types is read from $TYPO3_CONF_VARS['GFX']['imagefile_ext'].

Maximum width / height 

These are the maximum dimensions in pixels a picture will be bound to after the resize processing. Aspect ratio will of course be preserved.

Maximum image size (pixel area) 

This is the maximum size in pixels a picture will be bound to after the resize processing (thus height × width). Height and width are calculated as big as possible considering the defined maximum width / height. Aspect ratio will of course be preserved.

The field accepts the suffice "M" for megapixels.

Automatic orientation 

If this checkbox is ticked, TYPO3 will try to automatically rotate the picture. Many newer digital cameras (both dSLR and Point & Shoot digicams) have a built-in orientation sensor. Virtually all Canon and Nikon digital cameras have an orientation sensor. The output of this sensor is used to set the EXIF orientation flag in the image file's metadata to reflect the positioning of the camera with respect to the ground. Canon calls their sensor the "Intelligent Orientation" sensor. It is presumably a 2-axis tilt sensor, allowing 4 possible orientations to be detected (shown in the diagram below):

Keep profile and metadata 

Normally color profile and metadata information such as EXIF, IPTC and XMP are removed from the picture during the resize process. This option lets you keep them. Example of such information is shown below:

Resize PNG files with alpha channel 

By default PNG files which contain an alpha channel or a transparent color will not be resized because they are very likely to loose their transparency. If ticked, this checkbox will force all PNG files to be resized (if they meet the conditions of course).

Image type conversion mapping 

The mapping lets you automatically convert images from one format to another one during the resize processing. This is typically useful to convert non-Web formats (e.g., bmp and tif/tiff) to jpg or png.

PSR-14 Events 

The concept of PSR-14 events allows for easy implementation of the Observer pattern in software, something similar to signal and slots or hooks in former versions of TYPO3. Please read chapter Event dispatcher (PSR-14 events) from TYPO3 Core documentation.

Available events:

ImageResizedEvent

Event raised after an image has been resized.

ProcessDefaultConfigurationEvent

Event raised whenever the default configuration file config/image_autoresize.config.php does not exist, thus loading the default configuration for this extension. This event is typically useful if you want to provide other (better) default values for the configuration.

ProcessConfigurationEvent

Event raised after the configuration has been processed, allowing to alter it based on your own business logic.

Translating the extension 

Please help translating this extension by contributing on

https://crowdin.com/project/typo3-extension-imageautoresiz

Have more fun with TYPO3!

How to contribute 

This extension is using the same contribution workflow as for TYPO3 Core, but with GitHub PRs for the review process. Please read more about the workflow in the TYPO3 Contribution Guide.