I was just placing the cherry atop one of my fine art pieces --which in my engineering view means slapping a Gigantic text label on it so viewers recognize it immediately without the fol-de-rol--when I noticed NASTY pixel-wide vertical stripes in the text layer.


I've seen this before, but in one way or another, bumblerized it away.

Now it's back.

[SOLVED]
"Yay, verily, yay," to quote from the famous Danny Kaye movie, "The Court Jester," it's a consequence of setting Image->Mode->Grayscale.

Setting Image->Mode->RGB does not suffer from this.

I assumed I was simplifying things greatly by telling GIMP to use Grayscale ("don't worry about color"), but apparently that interferes with how it computates things.

I would appreciate any insights you could offer; bumblering is so time-consuming.

Thanks for being here.

Hello gramp:

I tried to duplicate your experience with the lines showing up when converting an image from RGB mode to Greyscale. I used a couple of different fonts and was not able to get the lines. However, it would be helpful if you provided the exact Font that you were using to create the Text. That way, I or someone else could test using that specific font.

However, I did notice that the lines in your image appear to occur at regular intervals. Using the Gimp Measure Tool, I was able to get a reading of 64 or 65 pixels between each line. If you had the Grid set as viewable and had the Grid Lines the same color as the background, that would give the appearance of lines slicing through the Text:



The above image is a Screenshot taken of my Gimp image window using a Custom Grid Line setup where the color of the Grid Lines are the same as the darker grey Background Color.

However, the appearance of those lines would not disappear once the image were changed to RGB mode. Yet, the regularity of those lines do suggest the use of a Grid. Since you mentioned "engineering", using a Grid for positioning would make sense from that perspective. If you are using a Grid, once you saved the work in anything other than XCF, that Grid would not show up on the final image, since it is just used for reference.

I am not saying that is what you are doing, just taking an educated guess, based on my own experience with using Gimp, and trying to diagnose problem issues. Hope this helps you some.

I often have thought because of these artifacts and things Gimp should have some sort of FINAL Viewer so you will see what the image looks like after every change. Just a small thumbnail of the precise GIF, JPG, or PNG view.
Maybe a VIEW EXACT button to render a preview really quick.
Just so the user knows those will not show in the image.Could save a lot of work for some folks.

All it would take is a script to quick save a temp and show it in a thumbnail image.

Well, I appreciate the blazes out of an educated guess. And I most especially appreciate you taking the trouble to try to cipher the distance between them to ferret out a clue.

The font I used was something called "SaloonExt Th". This is in Ubuntu, mind you.

Wait. "There's a grid?" (But I just checked, and it's been off apparently since I installed GIMP.)

Thanks.

Hi again gramp:

I downloaded and tested the font with Gimp. I am using a GNU/Linux OS also, but not Ubuntu. I was not able to duplicate the error that you are experiencing, sorry.

Can you try testing out opening some random image and convert it to Greyscale Mode to see if you get the lines with that? The regularity of those lines in the image seem to suggest some sort of overlayed pattern, perhaps the use of a Layer Mask with a pattern, or as I thought, perhaps a custom Grid was being used.

Otherwise, hopefully someone else here has some ideas about the source of the problem. Sorry that I was not able to help you to resolve that issue, nor determine the cause of it. If I come across any other ideas or thoughts, I will try to add them to the discussion.

Can you post your XCF?