.I want to change all the white pixels into transparent so that I can choose the background of my choice.
I may decide to use a black background, so multiply doesn't work.
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Sign up to join this communityUse the Background Eraser. Click on a white part of the image and hold down the mouse button - don't release it. Then erase over the entire image.
Duplicate your image layer, apply curves to the duplicate to invert all white to black and lighten everything else full or nearly white. Do not use tresholding, transition slope makes smoother result and you can tweak the result later to steeper:
If there's now much colors which are far from white, It's a good idea to lighten those colors withe Image adjust > Black and white or > Hue&Saturation.
Copy the result to the clipboard
Insert a layer mask to the original, Alt+click the mask icon in the layers panel to get the mask onscreen, Paste in place the inversion result
Click the image icon, close the inverted copy layer and see the result.
Layer mask accept editing, so you can make the slope steeper, if needed.
I guess you are not especially satisfied with the result. If you insert a new background, you see here and there mixes of white and the remeining colors:
Fix it by brushing green and blue to your image or fill it with a gradient. The layer mask prevents you to fill all. I used here some random colors only to show the principle:
It's still imperfect due the low resolution of the original image. The letters have bad edges. For better results you must have the image in higher resolution or in vector domain.