As shown in Figure 4, the SSIM analysis for HEIF image format further supports the findings of the PSNR evaluation. For HEIF images, the adaptive coding based quantum communication system reaches SSIM values nearing 0.9999 more quickly than the adaptive coding based classical system, demonstrating its superior ability to preserve structural details and overall image quality during transmission. This trend is especially pronounced in low SNR conditions (below 16 dB), where the proposed quantum system significantly outperforms the equivalent classical system. Similarly, as shown in Figure 5, for JPEG images, the proposed adaptive coding based quantum system reaches the maximum SSIM value of 0.9994 at an SNR of 12 dB, whereas the adaptive coding based classical system requires an SNR of 16 dB to achieve the same SSIM. This demonstrates the proposed quantum system’s superior efficiency in preserving image quality, especially under challenging transmission conditions, further underscoring its ability to outperform the equivalent classical system across various formats.