Interpolation type

At transformation serial recalculation from system of coordinates of output raster into system of coordinates of an input raster is carried out. Usually, the calculated point falls not into the center of pixel of input raster, and the area, limited by four adjacent pixels. In this case color of required pixel can be defined in the different ways:

- Nearest the neighbour. In a target raster a color of the pixel nearest to the calculated point on an initial raster is recorded. The maximal speed of transformation is reached, however on contrast rasters there is a change of straight lines on one pixel in places of discontinuity at the coordinates rounding.

- Bilinear interpolation. Color of pixel is defined by linear interpolation of color of four neighboring pixels. Average speed of transformation, there is no distortion of lines. In contrast rasters is a slight blurring on the border of regions of different colors.

- Bicubic interpolation. Color of pixel is determined by cubic interpolation of color of 16 neighboring pixels.

Maximum quality at the lowest speed of transformation. There is no distortion of lines and blurring of the borders on contrast rasters.

At the transformation of low-contrast images, such as photos, the difference in image quality at use of different types of interpolation is almost negligible.