Update cli.py to make POST method work

Use another class for post requirements:
Following the form example you give, classical HTML forms send form fields and not JSON, so you need to use Form for POST method (and not Query, as for GET method - read here for more : https://fastapi.tiangolo.com/tutorial/request-forms/?h=form+data) to be sure to retrieve correct data.

rembg/cli.py

@@ -9,7 +9,7 @@ import click
 import filetype
 import uvicorn
 from asyncer import asyncify
-from fastapi import Depends, FastAPI, File, Query
+from fastapi import Depends, FastAPI, File, Query, Form
 from fastapi.middleware.cors import CORSMiddleware
 from starlette.responses import Response
 from tqdm import tqdm
@@ -294,10 +294,10 @@ def s(port: int, log_level: str) -> None:
             ),
             a: bool = Query(default=False, description="Enable Alpha Matting"),
             af: int = Query(
-                default=240, ge=0, description="Alpha Matting (Foreground Threshold)"
+                default=240, ge=0, le=255, description="Alpha Matting (Foreground Threshold)"
             ),
             ab: int = Query(
-                default=10, ge=0, description="Alpha Matting (Background Threshold)"
+                default=10, ge=0, le=255, description="Alpha Matting (Background Threshold)"
             ),
             ae: int = Query(
                 default=10, ge=0, description="Alpha Matting (Erode Structure Size)"
@@ -311,6 +311,32 @@ def s(port: int, log_level: str) -> None:
             self.ae = ae
             self.om = om
 
+    class CommonQueryPostParams:
+        def __init__(
+            self,
+            model: ModelType = Form(
+                default=ModelType.u2net,
+                description="Model to use when processing image",
+            ),
+            a: bool = Form(default=False, description="Enable Alpha Matting"),
+            af: int = Form(
+                default=240, ge=0, le=255, description="Alpha Matting (Foreground Threshold)"
+            ),
+            ab: int = Form(
+                default=10, ge=0, le=255, description="Alpha Matting (Background Threshold)"
+            ),
+            ae: int = Form(
+                default=10, ge=0, description="Alpha Matting (Erode Structure Size)"
+            ),
+            om: bool = Form(default=False, description="Only Mask"),
+        ):
+            self.model = model
+            self.a = a
+            self.af = af
+            self.ab = ab
+            self.ae = ae
+            self.om = om
+            
     def im_without_bg(content: bytes, commons: CommonQueryParams) -> Response:
         return Response(
             remove(
@@ -355,7 +381,7 @@ def s(port: int, log_level: str) -> None:
             default=...,
             description="Image file (byte stream) that has to be processed.",
         ),
-        commons: CommonQueryParams = Depends(),
+        commons: CommonQueryPostParams = Depends(),
     ):
         return await asyncify(im_without_bg)(file, commons)