Test of noise addition.

<p>(a) Original image of Lena, (b) encrypted image of Lena without noise addition, (c) encrypted image of Lena under adding Pepper & Salt noise with noise density 0.005, (d) decrypted image under Pepper & Salt noise addition (noise density 0.005), (e) encrypted image of Lena under adding Pepper & Salt noise with noise density 0.05, (f) decrypted image under Pepper & Salt noise addition (noise density 0.05), (g) encrypted image of Lena under adding Pepper & Salt noise with noise density 0.5, (h) decrypted image under Pepper & Salt noise addition (noise density 0.5), (i) encrypted image of Lena under Gaussian white noise addition, (j) decrypted image under Gaussian white noise addition.</p

Test of image under brightening and darkening.

<p>(a) Brightened cipher-image of Lena, (b) decrypted image under brightening, (c) darkened cipher-image of Lena, (d) decrypted image under darkening.</p

NPCR and UACI of the color image of Lena when changing one pixel and permutation rounds <i>n</i> = 10.

<p>NPCR and UACI of the color image of Lena when changing one pixel and permutation rounds <i>n</i> = 10.</p

Test of image under rotation.

<p>(a) Rotated cipher-image of Lena, (b) decrypted image under rotation.</p

Comparison of the average NPCR and UACI values on the color image of Lena.

<p>Comparison of the average NPCR and UACI values on the color image of Lena.</p

Experimental results for Vegetables image.

<p>(a) Original image of Vegetables, (b) encrypted image of Vegetables, (c) decrypted image of Vegetables.</p

Histogram of the encrypted image of Lena in the (a) red, (b) green, (c) blue, components.

<p>Histogram of the encrypted image of Lena in the (a) red, (b) green, (c) blue, components.</p

Flowchart of the proposed image encryption algorithm.

<p>Flowchart of the proposed image encryption algorithm.</p

Test of image under cropping.

<p>(a) Cropped cipher-mage by removing 25% of the encrypted image of Lena (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119660#pone.0119660.g014" target="_blank">Fig. 14(b)</a>), (b) decrypted image of the cropped cipher-image (a), (c) cropped cipher-mage by removing 50% of the encrypted image of Lena (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0119660#pone.0119660.g014" target="_blank">Fig. 14(b)</a>), (d) decrypted image of the cropped cipher-image (c).</p

Comparison of encryption time between our proposed method and some other cryptosystems.

<p>Comparison of encryption time between our proposed method and some other cryptosystems.</p