A method comprising: determining a two dimensional block of pixels within an image for coding the image; coding the pixels in the two dimensional block of pixels using two dimensional differential pulse code modulation; creating a hybrid implicit / explicit bitstream by inserting an operational mode bit with a selected value in the bitstream that differentiates between implicit coding parameter determination and explicit coding parameter determination; when the operational mode bit with the selected value selects the explicit coding parameter determination, inserting a coding parameter indicator into the bitstream, wherein the coding parameter indicator indicates an adjustment to an implicitly determined coding parameter; wherein the implicitly determined coding parameter is a quantization parameter, and the adjustment is based upon a flatness determination for a group of pixels; wherein the flatness determination for the group of pixels comprises: determining whether a first set of pixels in the group meets a flatness threshold; if the first set of pixels meets the flatness threshold, adjusting the quantization parameter for the group of pixels; if the first set of pixels does not meet the flatness threshold, determining whether a second set of pixels in the group meets the flatness threshold; and if the second set of pixels meets the flatness threshold, adjusting the quantization parameter for the group of pixels. determining a two dimensional block of pixels within an image for coding the image; coding the pixels in the two dimensional block of pixels using two dimensional differential pulse code modulation; creating a hybrid implicit / explicit bitstream by inserting an operational mode bit with a selected value in the bitstream that differentiates between implicit coding parameter determination and explicit coding parameter determination; when the operational mode bit with the selected value selects the explicit coding parameter determination, inserting a coding parameter indicator into the bitstream, wherein the coding parameter indicator indicates an adjustment to an implicitly determined coding parameter; wherein the implicitly determined coding parameter is a quantization parameter, and the adjustment is based upon a flatness determination for a group of pixels; wherein the flatness determination for the group of pixels comprises: determining whether a first set of pixels in the group meets a flatness threshold; if the first set of pixels meets the flatness threshold, adjusting the quantization parameter for the group of pixels; if the first set of pixels does not meet the flatness threshold, determining whether a second set of pixels in the group meets the flatness threshold; and if the second set of pixels meets the flatness threshold, adjusting the quantization parameter for the group of pixels. determining whether a first set of pixels in the group meets a flatness threshold; if the first set of pixels meets the flatness threshold, adjusting the quantization parameter for the group of pixels; if the first set of pixels does not meet the flatness threshold, determining whether a second set of pixels in the group meets the flatness threshold; and if the second set of pixels meets the flatness threshold, adjusting the quantization parameter for the group of pixels.