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Image transformation to a circular arc

Wed Jul 20, 2022 5:07 am

GIMP Version: 2.8.14
Operating System: Mac OS
GIMP Experience: New User



Hello guys,

I am new and I am searching for an assistance to transform my image (to be specific - a soundvawe image) to a circular arc. I have reviewed plenty of video tutorials, however I could not find an answer to that. I've tried "curve bend" filter and "cage distort" tool, however I couldn't achieve what I wanted.

I am attaching an example of the initial sounwave image (Image 1) and the expected result (Image 2).

Thanks in advance.

Re: Image transformation to a circular arc

Wed Jul 20, 2022 6:10 am

Something like this: Gimp 2.8

map.jpg
map.jpg (120.51 KiB) Viewed 1280 times


Trim the ends with the crop tool
Colours -> Color-to-Apha to remove the white (white is default)
Increase the the canvas size so height = width and move the wave to the top of the canvas. Use the All-Layers option.
Use Filters -> Distorts -> Polar Coordinates and untick Map from Top
Demo animation 50 seconds https://i.imgur.com/cFL5H7j.mp4

To get something like your 'required' maybe do a bit of vertical stretching first.

Re: Image transformation to a circular arc

Wed Jul 20, 2022 6:21 am

This is "Filters > Distorts > Polar coordinates" with "To polar":

Polar2.jpg
Polar2.jpg (43.05 KiB) Viewed 1274 times

Re: Image transformation to a circular arc

Wed Jul 20, 2022 6:26 am

The pan to Bow scm filter may be of assistance as well.

script-fu-pan-to-bow.scm
(5 KiB) Downloaded 47 times


Just place it in your scripts folder and refresh scripts.
You'll find it here.

Script-Fu/Distorts/_Pan to Rainbow shape

Re: Image transformation to a circular arc

Wed Jul 20, 2022 6:49 am

Just open the script and type in the angle of circle you need (want), and let the filter run.
Here is my result on your image KEEPING the color profile and running the filter at 360 degrees.

Image 1-results-after-pan-to-bow-360-degrees.jpg
Image 1-results-after-pan-to-bow-360-degrees.jpg (186.46 KiB) Viewed 1270 times


This filter also utilizes Polar Coordinates in its code so most likely same results.

Re: Image transformation to a circular arc

Wed Jul 20, 2022 11:22 am

My try :hehe
Image

Re: Image transformation to a circular arc

Fri Jul 22, 2022 12:17 am

Pocholo, did you use map to sphere?

Re: Image transformation to a circular arc

Fri Jul 22, 2022 3:02 am

Pocholo, please share your knowledge how to achieve such result!

Re: Image transformation to a circular arc

Fri Jul 22, 2022 5:52 am

Here is small tutorial on how I archived my result:

Circular sound wave
1. Make the image canvas square shape: go to, Image/Canvas size and make both size even. Choose, Center and at the bottom for the Background make sure is on Transparent.

2. Use the "Scale tool" to stretch the image horizontally until it reaches the layer's edge or boundary.

3. If it have a white background, make it transparent; go to, Color/Color to Alpha
Set the Transparency Threshold to= 0.900

4. Make it rounded by going to, Filters/Distorts/Polar Coordinates.

5. Go to, Filters/Distorts/Lens Distortion. Set the "Main" Lever all away to the left.

6. Make the sound spike larger by going to, Filters/Blur/Zoom Motion Blur. Blurring Factor=1.2

7. Add a white Background layer and Merge the sound wave layer down.

8. Go to Filers/Enhance/Sharpen (Un-sharp mask). Make the Radius=20.00 and the Amount=6.0 (You can play with the levers until you think is right for you)

9. If you want the sound wave with a transparent background, just go to Colors/Color to Alpha. Make sure the Transparency Threshold is set to= 1.00

Re: Image transformation to a circular arc

Fri Jul 22, 2022 8:32 am

Filters >> Map >> Little Planet (this filter works faster than Polar coordinate and has a zoom)
This "writing" reminds me the movie "Arrival" :hehe

Untitled.jpg
Untitled.jpg (318.68 KiB) Viewed 1120 times

Re: Image transformation to a circular arc

Fri Jul 22, 2022 3:46 pm

Hi Patrice. Yes is easier, I did that my first try. But it doesn't look like the image he provided. Take a look at the sound spike, their not even like your example. They're long and short like the example I provided in post #6.

Re: Image transformation to a circular arc

Fri Jul 22, 2022 11:01 pm

Pocholo wrote:Hi Patrice. Yes is easier, I did that my first try. But it doesn't look like the image he provided. Take a look at the sound spike, their not even like your example. They're long and short like the example I provided in post #6.


Indeed you're right :bigthup
Thus I did some play, and depending the position of the wave (top, middle, or bottom) it will change the spikes length in or out.
ksnip_20220723-114724.png
ksnip_20220723-114724.png (284.41 KiB) Viewed 705 times


For a more precise and respectfulness of the wave, I agree that "Polar Coordinates" is the way to go, with "Little Planet" let say it's funnier :hehe
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