Scaling

[Abpujar]

Hi all, can anyone please help me to retrieve a scaling value of  image in illustrator. How can we identify which scaling has been applied to the image using script. I would like to know how to check whether the image has been applied horizontal scale or vertical scale. Thank you. 

[Ton Frederiks]

The Links panel gives scaling info.

[m1b]

Hi @Abpujar, please try this. - Mark

Edit 1: improved script.

Edit 2: updated script to better handle RasterItems which have flipped scale Y values. Still more work to fix fully.

Edit 3: now handles RasterItems and PlacedItems correctly (I think!).

/**
 * Get PlacedItem Scale And Rotation
 * for Adobe Illustrator
 *
 * by m1b
 * discussion: https://community.adobe.com/t5/illustrator-discussions/scaling/m-p/13050842
 *
 */


var doc = app.activeDocument,
    item = doc.selection[0],
    result = getLinkScaleAndRotation(item);

if (result)
    alert('Results:\nHorizontal scale: ' + result[0] + '%\nVertical scale: ' + result[1] + '%\nRotation: ' + result[2] + '°');



/**
 * Return a linked item's scale.
 * @author m1b
 * @param {PlacedItem|RasterItem} item - an Illustrator item
 * @returns {Array} [scaleX%, scaleY%, rotation°]
 */
function getLinkScaleAndRotation(item) {
    if (item == undefined)
        return;

    var m = item.matrix,
        rotatedAmount,
        unrotatedMatrix,
        scaledAmount;

    var flipPlacedItem = (item.typename == 'PlacedItem')
        ? 1
        : -1;

    try {
        rotatedAmount = item.tags.getByName('BBAccumRotation').value * 180 / Math.PI;
    } catch (error) {
        rotatedAmount = 0;
    }
    unrotatedMatrix = app.concatenateRotationMatrix(m, rotatedAmount * flipPlacedItem);
    scaledAmount = [unrotatedMatrix.mValueA * 100, unrotatedMatrix.mValueD * -100 * flipPlacedItem];

    return [round(scaledAmount[0]), round(scaledAmount[1]), round(rotatedAmount)];
}



/**
 * Rounds `n` to `places` decimal places.
 * @param {Number} n - the number to round
 * @param {Number} places - number of decimal places, can be negative
 * @returns {Number}
 */
function round(n, places) {
    var m = Math.pow(10, places || 4);
    return Math.round(n * m) / m;
}

[Abpujar]

Hi @m1b @thank you for the reply, I’m getting the scaling value but I need -ve or +ve value, for example if the image has been applied horizontal scale then the scaling value should be -ve or if the image has a vertical scale then the vertical scale value should be in -ve. If the image has not been applied any scaling then the scaling value should be in +ve. Thank you. 

[m1b]

I don't understand what you mean. Can you please give me some examples, eg.

200% horizontal, 150% vertical scale = ?

100% horizontal, 101% vertical scale = ?

101% horizontal, 100% vertical scale = ?

99% horizontal, 100% vertical scale = ?

Then I will understand. - Mark

[Abpujar]

for example If we give -100% horizontal ,100%vertical scale , in this scenario the image will be flip horizontally,(here I need to get the horizontal value as -ve). If we give 100% horizontal ,-100% vertical scale ,in this scenario the image will be flip vertically. if the image has been applied -ve scaling ,then I need to get -ve value.

how can we know whether the image has been flipped or not after applying scalingscaling using script. 

[m1b]

Hi @Abpujar, you are being so polite! You should have just said that my script didn't work! Haha. I've had another attempt. Please try again with the updated script above.

- Mark

[Abpujar]

Hi @m1b  i’ve tried ur updated script still I’m getting the same result as previous, I just want if the image has been flipped after applying scaling then the value should be -ve (-100). if we have manually given -ve scaling value the image will be flipped.

[m1b]

Okay, can you post a small sample illustrator file that shows the error?

- Mark

[Abpujar]

var xScale = Math.sqrt(my_matrix.mValueA my_matrix.mValueA + my_matrix.mValueB my_matrix.mValueB); var yScale = Math.sqrt(my_matrix.mValueC my_matrix.mValueC + my_matrix.mValueD my_matrix.mValueD); xScale = xScale * 100; yScale = yScale * 100;

Here I’m getting scaling value , how can we identify whether the image has been flipped or not after applying scaling.if the image has been flipped horizontally then the horizontal scaling value should be -100. How can we calculate ?

[m1b]

I need a sample file that has a placed image that shows the incorrect scale.

When I place an image and flip it horizontally, and run script, I see -100% hor, 100% vert which is correct. I want to understand why your test doesn't show that.

- Mark

[Abpujar]

Hi @ here I’ve not applied any scaling to this image but still it shows vertical scale value -100.

[m1b]

Yes I see @Abpujar, and I want to fix the script. The problem is that when I place an image myself and run script it correctly shows 100%, 100%. So I was hoping you could save your .ai file and post it here so I could see what's different about your file and mine. I can't easily fix something that works perfectly for me. Also which version of Adobe Illustrator are you using? Also did you place that image, or did it come in another way? I really need a sample file to look at. To post a sample file, drag the .ai file when you are replying here—down below where it says "Drag & drop here or browse files to attach".

- Mark

[Abpujar]

I'm using Adobe Illustrator CC 2018

[m1b]

Hi @Abpujar, thank you! That sample file is what I needed. Okay, believe it or not, but Illustrator shows a Y-flipped matrix for RasterItems compared with PlacedItems. (RasterItems are embedded images, not linked images.) I've updated my script above to better handle RasterItems but I notice it still doesn't give correct results if the rasterItem is scaled and rotated. I'll look into that when I get time.

- Mark

[m1b]

One more update to (hopefully) work correctly with both PlacedItems and RasterItems. @Abpujar, please try updated script above.

- Mark

[Abpujar]

Hi @m1b  still it is not working properly. I have tried it with different images. 

[Met1]

Did you flip it?

[Abpujar]

No I've not applied any property. 

[renél80416020]

Bonjour,

il me semble que vous devriez utiliser

scaledAmount = [unrotatedMatrix.mValueA * 100, unrotatedMatrix.mValueD * 100];

à la place de

scaledAmount = [unrotatedMatrix.mValueA * 100, unrotatedMatrix.mValueD * -100];

 René

[m1b]

Thanks @renél80416020, see my reply above. Strangely that Illustrator flips the Y scale in the matrix for PlaceItems—which I wrote the script originally for, assuming (wrongly!) that RasterItems would be handled the same.

- Mark

[renél80416020]

Bonjour m1b,

C'est puissant cette affaire, merci pour le partage...

Je me demande pourquoi utiliser "app.concatenateRotationMatrix"

et non pas tout simplement?

 scaledAmount = [m.mValueA * 100, m.mValueD * -100 * flipPlacedItem];

René

[Abpujar]

Hi @m1b the above code is still not working on different images. can u please check it once.

[m1b]

Hi @Abpujar, can you please post sample file of any .ai files that have images that script fails with?

[m1b]

Hi @renél80416020, I have to get an unrotated matrix before I can extract the scale value.

- Mark