Photoshop: Unexpected "Rectangular Marquee Tool" Behavior in Ps CC 14.2 x64

  • 1
  • Problem
  • Updated 5 years ago
  • Not a Problem
  • (Edited)
Zoom into the image as much as possible. Click "M". Make a selection, but do not release the mouse button. Now, move the cursor to the opposite direction. You can notice that at some point the side of the rectangle will shift by 1 px (See the GIF animation below.).



I think such behavior is incorrect.
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MilP

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Posted 5 years ago

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Jeffrey Tranberry, Sr. Product Manager, Digital Imaging

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Official Response
This is as designed. Looking at the screen grab – if you start a even just a screen pixel in and down from the top left corner of the magenta shape, it will include the physical magenta pixel in the active selection moving both in and out of the magenta color. (Note: you’re zoomed in 3200% so the physical pixels are enormous)

To illustrate: In the screen cap below, you start your crop here (a couple of screen pixels in on the magenta color). The physical pixels are denoted with the blue guides:

Photo of Jeffrey Tranberry

Jeffrey Tranberry, Sr. Product Manager, Digital Imaging

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Official Response
Look at my image above (taken from your animated gif), again. If instead you drag to the left or up from the cross-hair where you started your selection, you're starting by selecting part, albeit a sliver, of the magenta. Therefore, that physical magenta pixel will be considered selected and the selection marquee would snap over to the right and down to where the blue guides are. Essentially, partial selection of a pixel, no matter how small, selects all the pixel.