An apparatus for generating a stereoscopic image based on an original image by synthesizing images for left and right eyes, the apparatus comprising: pixel value storing means for storing a pixel value for each of pixels included in the original image, the pixel value being generated from any of brightness, saturation, or luminosity of the pixel; determining means for determining a depth value for each of the pixels included in the original image based on a comparison of pixel values between a pixel and at least one neighboring pixel; a depth value storing means for storing the depth value for each of the plurality of pixels, a threshold storing means for storing a threshold; and stereograph means for generating a stereoscopic image based on the depth values of the pixels determined by the determining means; wherein the determining means comprises: selecting means for sequentially selecting a plurality of pixels included in the original image in accordance with an arrangement of the plurality of pixels, the selected pixels lying in a prescribed direction; checking means for determining whether the pixel value of the pixel selected by the selecting means is larger or smaller than the pixel value of an adjacent pixel lying in the prescribed direction; counting means for counting a first count of a number of successive pixels for which pixel values are larger than the pixel value of the selected pixel, and a second count of a number of successive pixels for which pixel values are smaller than the pixel value of the selected pixel; comparing means for comparing each of the first and second counts with the threshold stored in the threshold storing means, changing means for determining an increasing or decreasing tendency in variation in pixel values by checking whether the pixel value of the selected pixel is larger or smaller than the pixel value of an adjacent pixel lying in the prescribed direction, and changing the determined depth value of the selected pixel by adding a predefined step value if a decreasing tendency is reversed, and subtracting the predefined step value if an increasing tendency is reversed, and changing the depth value stored in the depth value storing means by adding the predefined step value when the first count exceeds the threshold, and by subtracting the predefined step value when the second count exceeds the threshold. pixel value storing means for storing a pixel value for each of pixels included in the original image, the pixel value being generated from any of brightness, saturation, or luminosity of the pixel; determining means for determining a depth value for each of the pixels included in the original image based on a comparison of pixel values between a pixel and at least one neighboring pixel; a depth value storing means for storing the depth value for each of the plurality of pixels, a threshold storing means for storing a threshold; and stereograph means for generating a stereoscopic image based on the depth values of the pixels determined by the determining means; selecting means for sequentially selecting a plurality of pixels included in the original image in accordance with an arrangement of the plurality of pixels, the selected pixels lying in a prescribed direction; checking means for determining whether the pixel value of the pixel selected by the selecting means is larger or smaller than the pixel value of an adjacent pixel lying in the prescribed direction; counting means for counting a first count of a number of successive pixels for which pixel values are larger than the pixel value of the selected pixel, and a second count of a number of successive pixels for which pixel values are smaller than the pixel value of the selected pixel; comparing means for comparing each of the first and second counts with the threshold stored in the threshold storing means, changing means for determining an increasing or decreasing tendency in variation in pixel values by checking whether the pixel value of the selected pixel is larger or smaller than the pixel value of an adjacent pixel lying in the prescribed direction, and changing the determined depth value of the selected pixel by adding a predefined step value if a decreasing tendency is reversed, and subtracting the predefined step value if an increasing tendency is reversed, and changing the depth value stored in the depth value storing means by adding the predefined step value when the first count exceeds the threshold, and by subtracting the predefined step value when the second count exceeds the threshold.