Methods and apparatus, including computer program products, for compression include decomposing an image into wavelet transform coefficients, applying a first quantizer to the wavelet transform coefficients, and applying a second quantizer to a set of wavelet transform coefficients representing a background of the image. The method can include rounding the wavelet transform coefficients and rounding the wavelet transform coefficients can include rounding to a nearest integer value. The method can include multiplying the set rounded quantized background wavelet transform coefficients by the second quantizer and rounding all wavelet transform coefficients. Rounding all wavelet transform coefficients can include rounding to a nearest integer value.