Table Writer/Reader: Add Color information option when writing and reading table

Feedback & Ideas
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1

Hi,

when saving a Knime table, containing color information, via the table writer and reading it again, I noticed the color information is getting lost. I wonder if there are more “meta” information that might get lost too.

Anyways, I’d like to suggest to add an option to write and also read the color information.

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image1413×1326 341 KB

PS: Applying bug flag as well since this could be one too.

Best
Mike

2

Another nice idea @mwiegand!
Looking forward to receiving more votes on this. :slight_smile:

2 Likes
3

Hi @armingrudd,

I found a way to dynamically manage colors and while doing so created a test workflow that displays the bug.

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image1920×820 94.3 KB

Best
Mike

4

Hi @mwiegand

I have a few questions regarding the workflow:

1- The Extract Color node already had alpha (A) in 0-255 range and you have manually replaced it by 100 (Constant Value Column) then convert it back to 255 in the Python Script node to calculate RGBA (see point 2).

2- The RGBA is already calculated in the Extract Color node and you re-calculated it?

3- If the main point of this is to save color info along with the dataset (and then assign them back in Color Manager using flow vars one by one for each class), isn’t it (way) easier to wirte the color model along with the table and read them both once needed? (see a modified version of your workflow below)

Color Management - modified.knwf (221.7 KB)

1 Like
5

Hi @armingrudd,

outch, that hurts … thanks for pointing that out. I got completely blind and the lack of proper node documentation contributed even more to my mistake :exploding_head:

My brain was fully focused on the python script that I missed this. Apologize for the oversight. I updated the workflow.

Nevertheless, per W3C specs the alpha channel should be a value from 0-100, not 0-255. Though, this is a subject for the other topic I raised. Thanks again for pointing me to the right direction!

PS: About the other questions. I recalculated it for improve dynamic color management i.e. by ingesting rgba values. Furthermore, due to the lack of a node that “imports” / remaps lost color data, I created this approach to ease the struggle as well.

Best
Mike

1 Like