Adjusting brightness and contrast to a black and white image and exporting question!

Question

I'm an illustrator and recieved a scan of my work that needs some cleaning up with levels adjustments, brightness and contrast. I adjusted the brightness and contrast, which in the preview looked perfect, but when I clicked "OK", it went back to how it originally looked prior.

I tried using adjustmest layers, and that also worked great, however when I tried exporting the file to a flattened image, and it's as if nothing was changed to the original.

Is there any way to work around this?

Thanks!

D Fosse · Answer

You need to make the adjustment at View > 100% for an accurate preview. 100% means one image pixel is represented by exactly one physical screen pixel.

Whenever something seems to change when merging layers, it's because you are not viewing at 100%. The merged result is correct. The preview is misleading and incorrect.

This sounds like a "binary" image with either black or white pixels. Tonal adjustments have no effect on black or white pixels.

For performance reasons, all blending and adjustment previews are calculated on the on-screen version of the image. When you are zoomed out, that means a resampled and softened version of the image. Pixel levels are averaged out. You get a lot of intermediate values that aren't there in the full original data.

When you merge, commit an adjustment etc, the numbers are re-calculated on the full original data, pixel for pixel.

Viewing at 100% avoids all this and renders the whole issue moot. You see every pixel before and after, and so nothing changes.

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