Object and shape detection in digital images utilizing edge detection is described. In a first edge detection approach, phase transformation is utilized in the frequency domain, such as in response to Fourier transform, followed by use of a frequency-domain phase kernel and inverse-Fourier transform. Edge detection is also provided using a phase transform in the spatial domain utilizing a convolution approach. In a second edge detection approach, phase stretching is utilized, such as in combination with phase histogramming along with thresholding and morphological operations. Numerous example images are provided illustrating benefits of the disclosed technology with different applications and under different conditions.