A method for compressing an image, the method comprising: receiving an error level definition representing a maximum quantization error for compressing the image; identifying first transform coefficients to quantize within a first area of the image; selecting, based on the error level definition, a first sequence of quality control metrics for controlling a quantization of the first transform coefficients and evaluating image quality loss; wherein each quality control metric is associated with an error level definition and a quantization matrix for implementing a particular type of image content reduction; determining a first candidate bit cost by quantizing a first copy of the first transform coefficients according to the error level definition and the sequence of quality control metrics; determining a second candidate bit cost by quantizing a second copy of the first transform coefficients according to a modified error level and the sequence of quality control metrics; determining whether the second candidate bit cost is lower than the first candidate bit cost; responsive to determining that the second candidate bit cost is lower than the first candidate bit cost, iteratively processing the first transform coefficients according to the modified error level and the sequence of quality control metrics to produce first quantized transform coefficients; iteratively processing second transform coefficients of a second area of the image using a second sequence of quality control metrics to produce second quantized transform coefficients; producing a compressed image based on the first quantized transform coefficients and the second quantized transform coefficients; and wherein iteratively processing the first transform coefficients according to the modified error level and the sequence of quality control metrics to produce the first quantized transform coefficients comprises: quantizing the first transform coefficients using a first quality control metric of the sequence of quality control metrics, wherein quantizing the first transform coefficients using the first quality control metric results in a quantization error; determining that the quantization error exceeds a quality score calibration associated with the first quality control metric; and responsive to determining that the quantization error exceeds the quality score calibration, further quantizing the first transform coefficients using a second quality control metric of the sequence of quality control metrics. receiving an error level definition representing a maximum quantization error for compressing the image; identifying first transform coefficients to quantize within a first area of the image; selecting, based on the error level definition, a first sequence of quality control metrics for controlling a quantization of the first transform coefficients and evaluating image quality loss; wherein each quality control metric is associated with an error level definition and a quantization matrix for implementing a particular type of image content reduction; determining a first candidate bit cost by quantizing a first copy of the first transform coefficients according to the error level definition and the sequence of quality control metrics; determining a second candidate bit cost by quantizing a second copy of the first transform coefficients according to a modified error level and the sequence of quality control metrics; determining whether the second candidate bit cost is lower than the first candidate bit cost; responsive to determining that the second candidate bit cost is lower than the first candidate bit cost, iteratively processing the first transform coefficients according to the modified error level and the sequence of quality control metrics to produce first quantized transform coefficients; iteratively processing second transform coefficients of a second area of the image using a second sequence of quality control metrics to produce second quantized transform coefficients; producing a compressed image based on the first quantized transform coefficients and the second quantized transform coefficients; and wherein iteratively processing the first transform coefficients according to the modified error level and the sequence of quality control metrics to produce the first quantized transform coefficients comprises: quantizing the first transform coefficients using a first quality control metric of the sequence of quality control metrics, wherein quantizing the first transform coefficients using the first quality control metric results in a quantization error; determining that the quantization error exceeds a quality score calibration associated with the first quality control metric; and responsive to determining that the quantization error exceeds the quality score calibration, further quantizing the first transform coefficients using a second quality control metric of the sequence of quality control metrics. quantizing the first transform coefficients using a first quality control metric of the sequence of quality control metrics, wherein quantizing the first transform coefficients using the first quality control metric results in a quantization error; determining that the quantization error exceeds a quality score calibration associated with the first quality control metric; and responsive to determining that the quantization error exceeds the quality score calibration, further quantizing the first transform coefficients using a second quality control metric of the sequence of quality control metrics.