How to add text to an image from a flow variable

[johnprime]

Dear All

Is there a way to add text from a flow variable or column value to an image (preferably along the top or bottom.
This post in the forum hints that it might be possible, but without an example it’s very hard to attempt especially with the Labeling to PNG Images node configuration page not able to open unless compatible ImgPlusValue and LabelingValue columns are in spec.

Write text labels into an image for export

Hi all, is it possible to export a labeling with the name of each labeling written onto the image? The Bounding box renderer of the Interactive Segmentation view is useful but doesn't display the labels themselves (did I miss something)? I'm looking a way to export an annotated image for (offline) quality control, and for exporting during workflow execution (e.g. in each iteration of a loop). Should I look into the report designer for this? Jan  

Thanks in advance

John

[qqilihq]

Hi John,

you might also want to check this post:

Write text on an image

I don’t think there’s a really easy solution for that (in case there is, I’m curious as well). Based on some previous work, I’ve come up a workaround which involves converting your image to an SVG, adding the text layer and then (if necessary) convert it back into a pixel image. The core solution is in the Java Snippet node: [58] You can find the workflow on my NodePit Space: Feedback welcome! – Philipp

Should be pretty easy to wrap, so that you can pass the text from a variable.

Best,
Philipp

[johnprime]

Hi Philipp

Thanks for this. It certainly does work but the image resolution is badly degraded in the process.
Is there a way to retain good image resolution in your solution?

BW
John

[qqilihq]

Hi John,

@johnprime

It certainly does work but the image resolution is badly degraded in the process.
Is there a way to retain good image resolution in your solution?

I just had a look at the workflow: In the “Renderer to Image” node I set the image size to 640 x 640 back then (as this was more a proof of concept this worked fine). In case you have images of different sizes, it would be reasonable to configure this setting dynamically for each image which you process and to set it to the actual images’ sizes.

Does this make sense?

Best,
Philipp

[johnprime]

Hi Philipp

Yes that did the trick. My images were coming off the R plot node and it looks like users need to be quite generous with the image size compared to some of the other plotting nodes, and more importantly ensure those dimensions are retained in subsequent nodes like Render to Image to retain good resolution especially with the text.

Many Thanks
John