DepthBuffer low resolution

when i enable a shader that uses depthbuffer, there is extreme aliasing due to the low depthbuffer resolution.
my resolution is 2560x1080.
ibb.co/9T3gkfX

i tried to change some numbers in displaydepth.fx hoping that somehow i could fix it, even though i know nothing about coding.
so i changed the PixelSize.xy value and the aliasing was gone but the image flickered a lot.
so i assumed that the limitation is from the shader it self.


i changed the bold line value
________________________________________________________
float3 NormalVector(float2 texcoord)
{
    float3 offset = float3(ReShade:pixelSize.xy, 0.0);
    float2 posCenter = texcoord.xy;
    float2 posNorth  = posCenter - offset.zy;
    float2 posEast   = posCenter + offset.xz;

    float3 vertCenter = float3(posCenter, 1) * GetDepth(posCenter);
    float3 vertNorth  = float3(posNorth,  1) * GetDepth(posNorth);
    float3 vertEast   = float3(posEast,   1) * GetDepth(posEast);

    return normalize(cross(vertCenter - vertNorth, vertCenter - vertEast)) * 0.5 + 0.5;
}
________________________________________________________

if any one could me understand how i could increase the resolution, pls reply

What you are seeing is a visualization that tries to calculate screen space normals from the depth data in the depth buffer. This is not necessarily precise and can have artifacts, but that does not matter, it's only job is to make things easier to see for configuration. Other effects use the actual depth data as input, which has more precision, not the normals visualization (the data range that can be stored in the depth buffer is generally higher than what can be displayed as color, so the conversion for visualization is always lossy).

I tried a different shader that uses depth data(chromakey). but there is still allot of aliasing. I tried a variety of different shader and they give the same result. I tried using different depth buffers in the dx11 tab, but still same issue.

image of chroma key
ibb.co/xqRLvbp