Canon CanoScan D646U User Manual

Also see for CanoScan D646U: Product guide Quick start guide User guide User guide User guide

Contents

Canon CanoScan D646U User Manual Manual pdf 65 page image

65Scan ModeAny one of the various methods used to reproduce image data. Scan modes aredistinguished by the number of bits used to describe each pixel. Plug-in ModuleCS-U features the following scan modes.• Color: assigns 8 bits of data for each color channel (RGB) in each pixel. Eachpixel is therefore assigned 24 bits.• Grayscale: assigns 8 bits of data to its single color channel. Each pixel istherefore assigned 8 bits.• Black and White: assigns 1 bit of data to each pixel.ScanningThe process of using a scanner to read image data. Scanned data is sent to thecomputer as image data.ShadowsThe darkest portions of an image scanned in a color or grayscale image mode.Threshold ValueThe dividing value at which a pixel is determined to be either black or whitewhen the image is reproduced as a black and white image. The higher thethreshold, the darker the image. The lower the threshold, the brighter theimage.Tone CurveA function used to adjust image brightness. The tone curve (or gamma curve) isa graphic representation of the relationship of the input from the scanner to theoutput to the monitor or printer.Unsharp MaskA function that sharpens image outlines. Makes an image appear naturallysharper without changing the brightness, contrast or color balance.White Eyedropper ToolTool used to the select the brightest portion of an image in the preview area.Used with the Histogram function to adjust image brightness. When this tool isclicked on the image, all areas that are brighter are set to pure white.