Due to resource constraints, digital image transmissions are a significant challenge for image sensor based Wireless Sensor Networks (WSN). In this paper, we propose a novel robust and energy-efficient scheme, called Image Component Transmission (ICT) in WSN by providing various levels of reliability during image transmissions. Essential components such as the information for the positions of significant wavelet coefficients are transmitted with higher quality assurance. Relatively less important components such as the information for the values of pixels are transmitted with lower overhead. Simulation results show the proposed scheme achieves higher energy efficiency in WSN, with image transmission quality enhanced considerably by up to 6dB in terms of the Peak Signal to Noise Ratio (PSNR).