Comparison of four high-contrast data reduction methods applied to the K3 dataset of LkCa 15. The top row a)–d) shows the resulting images at a fixed linear stretch of ± 1.6 × 10^-3 times the stellar peak flux. In order of decreasing conservation of disk flux: a) PCA-assisted reference PSF subtraction, b) classical ADI, c) PCA-ADI, d) conservative LOCI. The bottom row e)–h) shows the same images after renormalizing each concentric annulus around the star by the standard deviation of the pixel values in the annulus at a stretch of ± 4σ. The resulting images resemble signal-to-noise maps, though the effective noise level is dominated by disk flux and thus overestimated in the inner ~0.̋5. Nevertheless, these images serve to reduce the dynamic range of the high-contrast images and visualize the characteristic crescent of positive disk flux left behind by the differential imaging methods.