An overdrive technology was developed and is widely used to diminish motion blur in LCDs. To store a previous frame in the overdrive operation in a limited-sized memory, simple image-compression techniques are required. By considering the strong correlation of nearby pixels in natural images, a new 6:1 color-image-compression method based on directional prediction is proposed. Different from the directional prediction of intra-coding in H.264/AVC, the predictable direction is determined beforehand to minimize the computation complexity. A simple content-adaptive quantization and bit-streaming method, which preserves image details and is free from blocking artifacts, is also proposed. The experimental results show that our proposed method outperforms the vector quantization block truncation coding method with an average 3-dB peak signal-to-noise ratio (PSNR) as well as the subjective quality in terms of blocking artifacts.