1. An endoscope apparatus comprising: an endoscope for picking up an image signal; an image generating portion for generating an image from the image signal picked up by the endoscope; an original image recording portion for temporarily recording the image generated by the image generating portion as an original image; an image correcting portion for performing image correction on the image generated by the image generating portion to generate a corrected image; a display device for displaying the corrected image; a measurement point designating portion for designating a measurement point on the corrected image displayed on the display device; and a measurement portion for transforming a pixel coordinate of the measurement point designated on the corrected image to a corresponding pixel coordinate on the original image, and performing measurement processing on the original image temporarily recorded by the original image recording portion using the corresponding pixel coordinate on the original image.