Dynamic Image Cache Configuration

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Target groups

Administrator (Web)
Developer (Web)

Context

The 'DIC' is used by OnlineChannel to create and deliver image variants on-the-fly. It needs some setup but afterwards image sizes can be defined very quickly; precalculated image-variant assets are obsolete.

Configuration

on server

Enable servers support for DIC within the censhare Admin-Client.

Master Data / File types --> define dic_master

Configuration / Modules / Image

--> Create additional Image [Server=*, Roles=*]

Configuration / Modules / Image

--> Create additional Image (automatic) Dynamic Image Cache Master [Server=*, Roles=*]

--> Copy necessary features from Standard Portal

asure 'DIC:Image format',
asure 'Transparente PNGs erstellen'
asure cropping to censhare:image-asset-crop.key & censhare:image-asset-crop.source-width, *height & censhare:image-asset-crop.source-y, *x

Satellite

Configure the service in ImageServiceConfiguration.

Simplified example

XML

<config version="1" storage-item="dic_master" storage-path="images" thread-pool-size="2" max-cache-size-in-mb="5000" max-age-in-minutes="1440">
    <rules>
       <size max-pixel-count="9000000"></size>
    </rules>
</config>

Configure the image specifications available to on instance within OnlineChannelConfiguration.

Simplified example

XML

<snip/>
  <image-requesthandler check-permissions="false" enabled="true" dynamic-calculation="false" >
    <image-preset name="m" width="427" quality="90" filetype="jpg" background-color="#FFFFFF"/>
    <image-preset name="xl" width="854" filetype="jpg" background-color="#FFFFFF"/>
    <image-preset name="xxl" width="1024" background-color="#FFFFFF"/>
    <image-preset name="xxs" width="101"/>
    <image-preset name="watermark-preview" width="1024" watermark-asset-id="18705" watermark-opacity="0.7"/>
  </image-requesthandler>
<snap/>

Also check the documentation on the OnlineChannelConfiguration

¹ Within skin use: image('ratio').presetName.src to get image url. By defining width or height in preset and ratio in req image size is complete defined.

² @since 5.7.x On images with transparency add features censhare:transparent-image to generate a DIC master image with transparency and censhare:oc.module.dic-image-type feature to deliver a png file.

good to know

you can not prevent the 'upscaling' of smaller images in DIC
- prevent using DIC, use master file (Feature: "Hauptdatei syncronisieren", cs-src=".node.@@model.image.isMasterStorageAvailable?string(.node.@@model.plain.master.src, .node.@@model.m.src)")
you can prevent cropping of images by adding feature censhare:module.oc.dic-image-no-crop. In this case always the whole image is used and scaled centered in surrounding image with the configurabel background color (default black) or transparent (for png).
if cropping fails or area is wrong: on large images with storage item 'master' having more pixel size than 'dic_master' the features censhare:image-asset-crop.reference-width and censhare:image-asset-crop.reference-height must be present to allow adaption of cropping values
to have a variable aspect ratio defined in skin do not provide aspect in preset