Algorithm 1 Proposed Algorithm for COVID-19 Detection

Input: COVID-19 Chest X-ray image dataset (D) with resize image (M) Extraction: Extract Feature Matrix (f). CNN Feature Vector (Fc). Step 1: Initialize ${\mathit{F}}_{\mathit{c}}$ ≥ ${\mathit{M}}_{\mathit{i}}\mathit{.}\mathit{i}=\mathbf{1}$ Step 2: Extract each image feature $D\left(\mathit{i}\mathbf{,}\mathbf{1}\mathbf{,}\mathbf{570}\right).$ Step 3: ${\mathit{F}}_{\mathit{c}}$ $\left(\mathit{i}\mathbf{,}\mathit{1}\right)$ = $M\left(\mathit{x}\mathbf{,}\mathbf{1}\right)$ + ${\mathit{F}}_{\mathit{c}} \left(\mathit{i}\mathbf{,}\mathbf{1}\right).$ Step 4: ${\mathit{F}}_{\mathit{c}}$ = overall CNN features. Histogram Oriented Gradient (HOG). Step 1: Initialize. ${\mathit{H}}_{\mathbf{0}}=\mathit{L}o\mathit{w} \mathit{p}\mathit{a}\mathit{s}\mathit{s} \mathit{o}\mathit{u}\mathit{t}\mathit{p}\mathit{u}\mathit{t}$,${\mathit{H}}_{\mathbf{1}}=\mathit{B}\mathit{a}\mathit{n}\mathit{d} \mathit{p}\mathit{a}\mathit{s}\mathit{s} \mathit{o}\mathit{u}\mathit{t}\mathit{p}u\mathit{t}$. Step 2: HOG $\left(\mathit{i}\mathbf{,}\mathbf{1}\right)$ = ${\mathit{H}}_{\mathbf{0}}$ $\left(\mathit{i}\mathbf{,}\mathbf{1}\right)$ + ${\mathit{H}}_{\mathbf{1}}$ $\left(\mathit{i}\mathbf{,}\mathbf{1}\right)$. Step 3: HOG = overall Histogram Oriented Gradient Fusion of features in Vector (V). $\mathit{T}\mathit{r}\mathit{a}\mathit{i}\mathit{n}\mathit{i}\mathit{n}\mathit{g} \mathit{f}\mathit{e}\mathit{a}\mathit{t}\mathit{u}\mathit{r}\mathit{e} \left(\mathit{V}\right)=[{\mathit{F}}_{\mathit{c}} \mathbf{,} \mathit{H}\mathit{O}\mathit{G}]$. $\mathit{t}\mathit{e}\mathit{s}\mathit{t}\_\mathit{i}\mathit{m}\mathit{a}\mathit{g}\mathit{e}=\mathit{i}\mathit{m}\mathit{r}\mathit{e}\mathit{a}\mathit{d}\left(\mathit{i}\mathit{m}\mathit{g}\right)$. Extract test feature (T) = repeat step 1, 2 from test_image. $\mathit{r}\mathit{e}\mathit{s}\mathit{u}\mathit{l}\mathit{t} \left(\mathit{i}\right)=\mathit{c}\mathit{l}\mathit{a}\mathit{s}\mathit{s}\mathit{i}\mathit{f}\mathit{y} \left(\mathit{t}\mathit{r}\mathit{a}\mathit{i}\mathit{n}\mathit{i}\mathit{n}\mathit{g} \mathit{f}\mathit{e}\mathit{a}\mathit{t}\mathit{u}\mathit{r}\mathit{e}\mathbf{,} \mathit{T}\right)$. Output: $\mathit{r}\mathit{e}\mathit{s}\mathit{u}\mathit{l}\mathit{t} \left(\mathit{i}\right)= COVID19 Positive or Normal.$