Bottom-left coordinates of the matrix after zoom

[drormekorot]

I'm using SkiaSharp in Xamarin to display an image and have implemented the functionality to zoom and pan.

Zoom and pan work great, and I want to stop the panning when the user reaches the image's boundaries.
I'm currently using Matrix.TransX and Matrix.TransY to get the coordinates of the top-left corner in the zoomed image, however this only allows me to correctly stop the movement when it is to the left and upwards. When TransX and TransY reach 0, I stop the movement.

When I try to stop the movement when it is to the right and downwards, the movement only stops when the top-left corner of the zoomed matrix is on top of the bottom-right corner of the original image

The issue is, I cannot find the correct way to calculate the bottom-left coordinates of the zoomed matrix.
I've taken the sizes of the zoomed matrix manually and got a linear function, but there are many image sizes and it will only work on that specific size.

For example, an image 1912 pixels on the X axis provide the following values of the zoomed matrix X axis for the following scales (I allow scales 1-6):

Scale Pixels
1.37 1906
1.59 1841
1.86 1811
4.52 1417
6.00 1127

How can I calculate the bottom-left coordinates of the zoomed matrix for all image sizes?