API Reference > imodeljs-frontend > Views > Viewport > readPixels readPixels Method Read selected data about each pixel within a rectangular region of this Viewport. readPixels(rect: ViewRect, selector: Pixel.Selector, receiver: Pixel.Receiver, excludeNonLocatable: boolean = false): void note The Pixel.Buffer supplied to the receiver function becomes invalid once that function exits. Do not store a reference to it. Parameter Type Description rect ViewRect The area of the viewport's contents to read. The origin specifies the upper-left corner. Must lie entirely within the viewport's dimensions. This input viewport is specified using CSS pixels not device pixels. selector Pixel.Selector Specifies which aspect(s) of data to read. receiver Pixel.Receiver A function accepting a Pixel.Buffer object from which the selected data can be retrieved, or receiving undefined if the viewport is not active, the rect is out of bounds, or some other error. The pixels received will be device pixels, not CSS pixels. See Viewport.devicePixelRatio and Viewport.cssPixelsToDevicePixels. excludeNonLocatable boolean If true, geometry with the "non-locatable" flag set will not be drawn. Returns - void Defined in core/frontend/src/Viewport.ts Line 2404 Last Updated: 12 June, 2024