Pixel art resizing allows you to upsample your document using one of two renowned pixel art resampling algorithms: XBR and HQX.
Before: Image upsampled 4x using Bicubic filter. Observe the jaggy edges and ringing. After: Image upsampled 4x using XBR filter. See how the edges are smoother and more refined. To resize using pixel art filters:
From the Document menu, select Resize.
Set the Resize option to Pixel.
Choose from either HQX or XBR as the resampling method under Mode, and pick a Size multiplier from 2x, 3x or 4x.