Resize and crop by any single dimension

README.md

@@ -12,7 +12,7 @@ image_filter watermark;
 
 image_filter_watermark_width_from 300;
 image_filter_watermark_height_from 400;
-    
+
 image_filter_watermark "PATH_TO_FILE";
 image_filter_watermark_position center-center; # top-left|top-right|bottom-right|bottom-left|right-center|left-center|bottom-center|top-center|center-center|center-random`
 ```
@@ -77,3 +77,43 @@ Usage with resize and crop:
        image_filter_watermark_position center-center;
    }
 ```
+
+Resize and crop can omit any dimension value
+
+* For example, nginx locations configuration:
+
+```
+location /resize/ {
+    alias /path/to/background/image;
+
+    image_filter resize $arg_w $arg_h;
+
+    image_filter_watermark /path/to/watermark/image;
+    image_filter_watermark_position center-center;
+}
+
+location /crop/ {
+    alias /path/to/background/image;
+
+    image_filter crop $arg_w $arg_h;
+
+    image_filter_watermark /path/to/watermark/image;
+    image_filter_watermark_position center-center;
+}
+```
+
+* Requests with args:
+
+1. for proportionally reduces an image to the specified width
+
+```
+    http://localhost/resize/test.png?w=200
+    http://localhost/resize/test.png?w=200&h=-
+```
+
+2. for proportionally reduces an image to the width size and crops by height
+
+```
+    http://localhost/crop/test.png?h=250
+    http://localhost/crop/tets.png?w=-&h=250
+```

ngx_http_image_filter_module.c

@@ -621,27 +621,25 @@ ngx_http_image_process(ngx_http_request_t *r)
         return ngx_http_image_resize(r, ctx);
     }
 	}
-	ctx->max_width = ngx_http_image_filter_get_value(r, conf->wcv, conf->width);
 
-    if (ctx->max_width == 0) {
-        return NULL;
-    }
+    ctx->max_width = ngx_http_image_filter_get_value(
+                                    r,
+                                    conf->wcv,
+                                    conf->width
+                            );
 
-    ctx->max_height = ngx_http_image_filter_get_value(r, conf->hcv,
-                                                      conf->height);
-    if (ctx->max_height == 0) {
+    ctx->max_height = ngx_http_image_filter_get_value(
+                                    r,
+                                    conf->hcv,
+                                    conf->height
+                            );
+
+    if (ctx->max_width == 0 && ctx->max_height == 0) {
         return NULL;
     }
 
-    if (rc == NGX_OK
-        && ctx->width <= ctx->max_width
-        && ctx->height <= ctx->max_height
-        && ctx->angle == 0
-        && !ctx->force
-        && !conf->watermark.data)
-    {
-        return ngx_http_image_asis(r, ctx);
-    }
+    if(ctx->max_width == 0)  ctx->max_width =ctx->width;
+    if(ctx->max_height == 0) ctx->max_height=ctx->height;
 
     return ngx_http_image_resize(r, ctx);
 }