A data processing method for rapidly suppressing background high-frequency noise in a digitized image, in which the data processing method comprises configuring a graphical processing unit or a central processing unit to execute following steps: obtaining an input image (INPUT), wherein the input image (INPUT) has a first width and a first height, and includes a plurality of pixels or data points; performing a first amplification process on the input image (INPUT) to multiply the input image (INPUT) by a first amplification factor, and generate a first amplified image; performing a pixel binning process or a first interpolation process on the first amplified image to resize the first amplified image by a reduction factor to generate a first resized image (RESIZE1) that has a second width lower than the first width by the reduction factor and a second height lower than the first height by the reduction factor; performing a first low-pass filtering process on the first resized image (RESIZE1) to obtain a first blurred image (BLUR1); performing a second interpolation process on the first blurred image (BLUR1) to upscale the first blurred image (BLUR1) from the second width and the second height to obtain a second resized image (RESIZE2) having the first width and first height; performing a first subtraction process on the second resized image (RESIZE2) and the first amplified image to subtract the first amplified image from the second resized image (RESIZE2), so as to generate a first subtracted image; performing a second low-pass filtering process on the first subtracted image to obtain a second blurred image (BLUR2); performing a second amplification process on the second blurred image (BLUR2) to multiply the second blurred image (BLUR2) by a second amplification factor, and generate a subtraction mask (MASK) having the first width and first height; and performing a second subtraction process on the input image (INPUT) and the subtraction mask (MASK) to subtract the subtraction mask (MASK) from the input image (INPUT) to generate an output image. obtaining an input image (INPUT), wherein the input image (INPUT) has a first width and a first height, and includes a plurality of pixels or data points; performing a first amplification process on the input image (INPUT) to multiply the input image (INPUT) by a first amplification factor, and generate a first amplified image; performing a pixel binning process or a first interpolation process on the first amplified image to resize the first amplified image by a reduction factor to generate a first resized image (RESIZE1) that has a second width lower than the first width by the reduction factor and a second height lower than the first height by the reduction factor; performing a first low-pass filtering process on the first resized image (RESIZE1) to obtain a first blurred image (BLUR1); performing a second interpolation process on the first blurred image (BLUR1) to upscale the first blurred image (BLUR1) from the second width and the second height to obtain a second resized image (RESIZE2) having the first width and first height; performing a first subtraction process on the second resized image (RESIZE2) and the first amplified image to subtract the first amplified image from the second resized image (RESIZE2), so as to generate a first subtracted image; performing a second low-pass filtering process on the first subtracted image to obtain a second blurred image (BLUR2); performing a second amplification process on the second blurred image (BLUR2) to multiply the second blurred image (BLUR2) by a second amplification factor, and generate a subtraction mask (MASK) having the first width and first height; and performing a second subtraction process on the input image (INPUT) and the subtraction mask (MASK) to subtract the subtraction mask (MASK) from the input image (INPUT) to generate an output image.