Effect of subtraction of diffuse background in SFR tracers on spatially-resolved (∼560 pc) Schmidt relations in NGC 0628. Upper panel: analysis on the images with diffuse background (no subtraction). Lower panel: analysis on the images where diffuse background is subtracted. Left panel: Σ_SFR versus Σ_H I, middle panel: Σ_SFR versus Σ_H2. Right panel: Σ_SFR versus Σ_H I+H2. The error bars include the random error and systematic error on the flux measurements. The solid black line in each plot denotes the best-fit line to the data where equal weight is given to each data point on both axes. N and A denote the power-law index and the star-formation efficiency. The slope of the Σ_SFR versus Σ_H2 and Σ_SFR versus Σ_H I+H2 increases after subtraction of diffuse background. We note the saturation of H I at ∼10 M_⊙ pc⁻². Here, we assumed a Kroupa IMF and adopted a constant X(CO) factor = 2.0 × 10²⁰ cm⁻² (K km s⁻¹)⁻¹.