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Whenever data is removed from or added to the image, the image quality degrades to some extent. When you decrease the number of pixels ( downsampling), the application removes data. When you increase the number of pixels in this part of the dialog box ( upsampling), the application adds data to the image. Resampling changes the total number of pixels in the image, which are displayed as Width and Height in pixels in the Image Size dialog.
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To resample your image, ensure that Resample is selected at the bottom of the Image Size dialog. When you resize and resample an image, you change the amount of data in that file. Pressing these keys changes the Cancel button to a Reset button. Tip:To reset the Image Size dialog to its original state, press Alt (Windows) or Option (macOS). You may have to do some extra work, such as using the Unsharp Mask filter to sharpen your image, to compensate for the resampling. When you resample, the image quality can degrade to some extent.
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Or, you can maintain the same amount of data in the image ( resizing without resampling). You can increase or decrease the amount of data in the image ( resampling). The Image Size dialog allows you to resize your images in two ways.
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