exact percentage of colours in a picture

[ashr]

HI, Is there a way i could find the exact percentage of a certain colour from a picture in affinity designer V.3.1? 

i tried using the levels adjustment but it shows only black and white levels.

 

for example the below picture has 2 colours yellow and blue, can i find out the percentage of yellow colour? 

 

affinity designer v.3.1 

on ipad pro 17.2 version 6th generation 

 

 

 

[Alfred]

1 hour ago, ashr said:

Is there a way i could find the exact percentage of a certain colour from a picture in affinity designer V.3.1? 

This Question topic doesn’t belong in the Bugs section. Perhaps a moderator will move it.

1 hour ago, ashr said:

i tried using the levels adjustment but it shows only black and white levels.

The percentages shown in the Levels adjustment controls are there for you to tweak the settings, not to tell you the black and white content of the image, so I can’t see how that could help.

1 hour ago, ashr said:

affinity designer v.3.1

AD version 3 is years away! I presume you mean 2.3.1.

[stokerg]

Hi @ashr,

There isn't a way to do this currently as there is no Info Panel in the iPad build of Affinity Designer or Affinity Photo, which you could use to find this out.   This has been requested several times to be added to the iPad build of Affinity.  

The Desktop version of Affinity Photo does have an Info Panel, which you could use to find out the values.

[Paul Mudditt]

On 2/19/2024 at 7:13 AM, ashr said:

HI, Is there a way i could find the exact percentage of a certain colour from a picture in affinity designer V.3.1? 

i tried using the levels adjustment but it shows only black and white levels.

 

for example the below picture has 2 colours yellow and blue, can i find out the percentage of yellow colour? 

 

affinity designer v.3.1 

on ipad pro 17.2 version 6th generation 

 

 

 

As @stokerg mentions the iPad lacks the info panel but the workaround is to make sure you have nothing selected in the layers panel, then use the colour studio eye dropper to pick the colour and tap the selected colour to show its makeup. Quick demo.

[Alfred]

29 minutes ago, Paul Mudditt said:

use the colour studio eye dropper to pick the colour and tap the selected colour to show its makeup

That just shows you the CMYK percentages for each colour.  The OP asked:

On 2/19/2024 at 7:13 AM, ashr said:

for example the below picture has 2 colours yellow and blue, can i find out the percentage of yellow colour? 

In other words, is it 62% yellow (and therefore 38% blue), or what?

[NotMyFault]

On 2/19/2024 at 8:13 AM, ashr said:

HI, Is there a way i could find the exact percentage of a certain colour from a picture in affinity designer V.3.1? 

Can you please explain what exactly do you mean by percentage of color?
In relation to what metric?
Which color model (RGB, CMYK)?

color channels or spot colors (tint)?

[NotMyFault]

There are many tricks to indirectly measure color values on iPad even without info panel.

• use blend range to show only specific small color ranges.
• use fill layer with blend mode difference. Black pixel show matching areas. May add levels adjustment on top to boost sensitivity 
• use procedural texture filter (developed on Desktop version) to measure delta E to given reference color (entered by sliders or numeric input)

[Alfred]

4 minutes ago, NotMyFault said:

There are many tricks to indirectly measure color values on iPad even without info panel.

• use blend range to show only specific small color ranges.
• use fill layer with blend mode difference. Black pixel show matching areas. May add levels adjustment on top to boost sensitivity 
• use procedural texture filter (developed on Desktop version) to measure delta E to given reference color (entered by sliders or numeric input)

I’d be interested to see a demonstration of how to use such tricks to determine this info:

18 minutes ago, Alfred said:

is it 62% yellow (and therefore 38% blue), or what?

 

[Paul Mudditt]

On 2/20/2024 at 9:45 AM, Alfred said:

That just shows you the CMYK percentages for each colour.  The OP asked:

In other words, is it 62% yellow (and therefore 38% blue), or what?

I made the assumption that @ashr (as a newbie to the forums) actually wanted similar to info panel to be able to replicate a colour and that can be achieved all be it slightly more complicated as my video shows. The efforts involved calculating % yellow is interesting but not what the op really wanted to know in my personal opinion.

Edited February 22 by Paul Mudditt
removed “possible incorrect assumption” statement

[NotMyFault]

On 2/19/2024 at 8:13 AM, ashr said:

for example the below picture has 2 colours yellow and blue, can i find out the percentage of yellow colour? 

 

Basic approach:

• Create a new pixel layer. Fill with black. Deactivate.
• Use selection by color to select given range. Adjust tolerance settings as needed.
• Choose black layer. Use fill with white on selected area.
• deselect all
• Filter->blur->average
• Sample color and note lightness value. This gives percentage of colored pixel to all pixels p1. (On desktop, histogram shows the actual number of pixels in white when hovering over)
•  
• Repeat for second color, getting p2
• the quotient  p1/(p1+p2) is what you asked for.

This method can be improved / simplified.

[NotMyFault]

For this image I estimate 84% yellow and 16% blue pixels. There is some uncertainty as the dark pixels cannot be counted correctly with my method.

[carl123]

Another way

A quick rough method, using the Histogram Marque Checkbox and pixel count in that dialog

 

1. Remove the white background (needs to be a transparent background)

 

2. Select > Alpha Range > Select Fully Transparent

Select > Invert Pixel Selection (will give the total of Opaque & Partially Transparent pixels)

This gives a total Pixel count of 119020 (in the Histogram)

3. Select > Colour Range > Select Blues

Gives a Pixel count of 22554 (in the Histogram)

 

4. Subtract 22554 from 119020 to get 96,466 (i.e. the remaining yellow pixels)

You can now calculate the percentage values for blue and yellow

Blue = 22554/119020 = 18.9%

Yellow =96,466/119020 = 81.1%

This is for the Desktop version; I don't know if the iPad has the same options to do this or indeed how accurate the Histogram is when counting pixels
 

[NotMyFault]

On 2/20/2024 at 11:03 AM, Alfred said:

I’d be interested to see a demonstration of how to use such tricks to determine this info:

 

The linked reply has a file attached which shows all pixels of one exact grey value. With help of info panel (on desktop), histogram (on desktop) of color panel it allows to spot pixels of certain colors and count them by blur filters which helps to calculate percentage from black / white pixel layers.