preserve img-cfg default behavior

Author: leejet

examples/cli/README.md

@@ -129,7 +129,8 @@ Generation Options:
   --hires-upscale-tile-size <int>          highres fix upscaler tile size, reserved for model-backed upscalers (default:
                                            128)
   --cfg-scale <float>                      unconditional guidance scale: (default: 7.0)
-  --img-cfg-scale <float>                  image guidance scale for inpaint or image edit models: (default: 1.0)
+  --img-cfg-scale <float>                  image guidance scale for inpaint or image edit models: (default: same as
+                                           --cfg-scale)
   --guidance <float>                       distilled guidance scale for models with guidance input (default: 3.5)
   --slg-scale <float>                      skip layer guidance (SLG) scale, only for DiT models: (default: 0). 0 means
                                            disabled, a value of 2.5 is nice for sd3.5 medium
@@ -140,7 +141,7 @@ Generation Options:
   --flow-shift <float>                     shift value for Flow models like SD3.x or WAN (default: auto)
   --high-noise-cfg-scale <float>           (high noise) unconditional guidance scale: (default: 7.0)
   --high-noise-img-cfg-scale <float>       (high noise) image guidance scale for inpaint or image edit models (default:
-                                           1.0)
+                                           same as --cfg-scale)
   --high-noise-guidance <float>            (high noise) distilled guidance scale for models with guidance input
                                            (default: 3.5)
   --high-noise-slg-scale <float>           (high noise) skip layer guidance (SLG) scale, only for DiT models: (default:

examples/common/common.cpp

@@ -940,7 +940,7 @@ ArgOptions SDGenerationParams::get_options() {
          &sample_params.guidance.txt_cfg},
         {"",
          "--img-cfg-scale",
-         "image guidance scale for inpaint or image edit models: (default: 1.0)",
+         "image guidance scale for inpaint or image edit models: (default: same as --cfg-scale)",
          &sample_params.guidance.img_cfg},
         {"",
          "--guidance",
@@ -972,7 +972,7 @@ ArgOptions SDGenerationParams::get_options() {
          &high_noise_sample_params.guidance.txt_cfg},
         {"",
          "--high-noise-img-cfg-scale",
-         "(high noise) image guidance scale for inpaint or image edit models (default: 1.0)",
+         "(high noise) image guidance scale for inpaint or image edit models (default: same as --cfg-scale)",
          &high_noise_sample_params.guidance.img_cfg},
         {"",
          "--high-noise-guidance",

examples/server/README.md

@@ -231,7 +231,8 @@ Default Generation Options:
   --hires-upscale-tile-size <int>          highres fix upscaler tile size, reserved for model-backed upscalers (default:
                                            128)
   --cfg-scale <float>                      unconditional guidance scale: (default: 7.0)
-  --img-cfg-scale <float>                  image guidance scale for inpaint or image edit models: (default: 1.0)
+  --img-cfg-scale <float>                  image guidance scale for inpaint or image edit models: (default: same as
+                                           --cfg-scale)
   --guidance <float>                       distilled guidance scale for models with guidance input (default: 3.5)
   --slg-scale <float>                      skip layer guidance (SLG) scale, only for DiT models: (default: 0). 0 means
                                            disabled, a value of 2.5 is nice for sd3.5 medium
@@ -242,7 +243,7 @@ Default Generation Options:
   --flow-shift <float>                     shift value for Flow models like SD3.x or WAN (default: auto)
   --high-noise-cfg-scale <float>           (high noise) unconditional guidance scale: (default: 7.0)
   --high-noise-img-cfg-scale <float>       (high noise) image guidance scale for inpaint or image edit models (default:
-                                           1.0)
+                                           same as --cfg-scale)
   --high-noise-guidance <float>            (high noise) distilled guidance scale for models with guidance input
                                            (default: 3.5)
   --high-noise-slg-scale <float>           (high noise) skip layer guidance (SLG) scale, only for DiT models: (default:

src/stable-diffusion.cpp

@@ -2853,7 +2853,7 @@ char* sd_sample_params_to_str(const sd_sample_params_t* sample_params) {
              sample_params->guidance.txt_cfg,
              std::isfinite(sample_params->guidance.img_cfg)
                  ? sample_params->guidance.img_cfg
-                 : 1.0f,
+                 : sample_params->guidance.txt_cfg,
              sample_params->guidance.distilled_guidance,
              sample_params->guidance.slg.layer_count,
              sample_params->guidance.slg.layer_start,
@@ -3338,7 +3338,7 @@ struct GenerationRequest {
         // img_cfg == txt_cfg means that img_cfg is not used
         bool img_cfg_was_unset = !std::isfinite(guidance->img_cfg);
         if (!std::isfinite(guidance->img_cfg)) {
-            guidance->img_cfg = 1.0f;
+            guidance->img_cfg = guidance->txt_cfg;
         }
 
         if (!sd_version_supports_img_cfg(sd_ctx->sd->version, has_ref_images)) {