In this paper a new blind technique using one dimensional Walsh coding to improve the robustness of image watermarking is presented. The proposed technique inserts the binary bits of handwritten signatures in the DCT blocks of the Y channel of the digital color image. The 1-D Walsh coding can be applied either horizontally or vertically. The work was carried out using the horizontal 1-D Walsh coding. Results prove that the use of Walsh coding has improved robustness against JPEG compression.