1. An apparatus for image/video compression utilizing spatially decorrelated blocks of picture elements (pixels) in at least one image or at least one video frame comprising: a memory; and a processor coupled to the memory, the processor configured to: receive a block of input sample values corresponding to a block of pixels via an interface, determine if the block of input sample values comprises full input value or scaled input values and: if the block of input sample values comprises full input values, then perform a full two-dimensional (2D) transform on the block of input sample values to obtain a block of output values corresponding to a block of encoded pixels, comprising: performing a scaled one-dimensional (1D) transform on each row of the block of input sample values to obtain a first intermediate block, performing a scaled 1D transform on each column of the first intermediate block to obtain a second intermediate block comprising scaled transform coefficients, and scaling the second intermediate block to obtain a block of output values, and if the block of input sample values comprises scaled input values, then perform a scaled two-dimensional (2D) transform on the block of input sample values to obtain a block of output values corresponding to a block of encoded pixels, comprising: performing a scaled one-dimensional (1D) transform on each row of the block of input sample values to obtain a first intermediate block, performing a scaled 1D transform on each column of the first intermediate block to obtain a second intermediate block comprising scaled transform coefficients, and scaling the second intermediate block to obtain a block of output values, quantizing and entropy encoding the block of output values to form a compressed data unit, and transmitting the compressed data unit.