feat: support Ideogram4 in stablediffusion-ggml backend + gallery (#10201)

* feat(stablediffusion-ggml): support Ideogram4 unconditional diffusion model

Bump stable-diffusion.cpp from 1f9ee88 to b9254dd, the upstream commit that
adds Ideogram4 support (leejet/stable-diffusion.cpp#1609). Ideogram4 derives
its classifier-free guidance from a separate unconditional diffusion model,
exposed upstream through the new sd_ctx_params_t.uncond_diffusion_model_path
field.

Wire that field into the gosd wrapper via a new uncond_diffusion_model_path
option. The _path suffix is deliberate: the Go loader only resolves options
whose name contains "path" to an absolute path under the model directory, so
this keeps the option consistent with diffusion_model_path and
high_noise_diffusion_model_path.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: Claude:claude-opus-4-8 [Claude Code]

* feat(gallery): add Ideogram4 stablediffusion-ggml models

Single-file GGUF weights for Ideogram4 are now published
(stduhpf/ideogram-4-gguf), so add the model to the gallery. Ideogram4 is a
text-to-image model with strong, accurate in-image text rendering, driven by
a Qwen3-VL-8B text encoder and real classifier-free guidance from a separate
unconditional diffusion model (the uncond_diffusion_model_path support added
in the preceding commit).

Two index entries, both built on gallery/virtual.yaml with the full config
inlined in overrides (same pattern as the other models, no dedicated template
file):
- ideogram-4-iq4nl-ggml (4-bit, ~11.6GB diffusion)
- ideogram-4-q8_0-ggml  (8-bit, ~20GB diffusion)

Each bundles the diffusion + unconditional GGUF (stduhpf), the
Qwen3-VL-8B-Instruct text encoder (unsloth), and the FLUX.2 VAE (Comfy-Org
mirror, non-gated). cfg_scale is 7 to match the upstream Ideogram4 default,
since it performs real CFG unlike the guidance-distilled Flux/Z-Image models.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: Claude:claude-opus-4-8 [Claude Code]

---------

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>

backend/go/stablediffusion-ggml/Makefile

@@ -8,7 +8,7 @@ JOBS?=$(shell nproc --ignore=1)
 
 # stablediffusion.cpp (ggml)
 STABLEDIFFUSION_GGML_REPO?=https://github.com/leejet/stable-diffusion.cpp
-STABLEDIFFUSION_GGML_VERSION?=1f9ee88e09c258053fa59d5e05e23dfb10fa0b13
+STABLEDIFFUSION_GGML_VERSION?=b9254dda0d10b91ee6f17fb7f4420097dd29824b
 
 CMAKE_ARGS+=-DGGML_MAX_NAME=128
 

backend/go/stablediffusion-ggml/cpp/gosd.cpp

@@ -386,6 +386,7 @@ int load_model(const char *model, char *model_path, char* options[], int threads
     const char *llm_vision_path = "";
     const char *diffusion_model_path = stableDiffusionModel;
     const char *high_noise_diffusion_model_path = "";
+    const char *uncond_diffusion_model_path = "";
     const char *taesd_path  = "";
     const char *control_net_path = "";
     const char *embedding_dir = "";
@@ -472,6 +473,7 @@ int load_model(const char *model, char *model_path, char* options[], int threads
         if (!strcmp(optname, "llm_vision_path")) llm_vision_path = strdup(optval);
         if (!strcmp(optname, "diffusion_model_path")) diffusion_model_path = strdup(optval);
         if (!strcmp(optname, "high_noise_diffusion_model_path")) high_noise_diffusion_model_path = strdup(optval);
+        if (!strcmp(optname, "uncond_diffusion_model_path")) uncond_diffusion_model_path = strdup(optval);
         if (!strcmp(optname, "taesd_path")) taesd_path = strdup(optval);
         if (!strcmp(optname, "control_net_path")) control_net_path = strdup(optval);
         if (!strcmp(optname, "embedding_dir")) {
@@ -571,6 +573,7 @@ int load_model(const char *model, char *model_path, char* options[], int threads
     ctx_params.llm_vision_path = llm_vision_path;
     ctx_params.diffusion_model_path = diffusion_model_path;
     ctx_params.high_noise_diffusion_model_path = high_noise_diffusion_model_path;
+    ctx_params.uncond_diffusion_model_path = uncond_diffusion_model_path;
     ctx_params.vae_path = vae_path;
     ctx_params.audio_vae_path = audio_vae_path;
     ctx_params.embeddings_connectors_path = embeddings_connectors_path;

gallery/index.yaml

@@ -26165,6 +26165,106 @@
     - filename: ae.safetensors
       sha256: afc8e28272cd15db3919bacdb6918ce9c1ed22e96cb12c4d5ed0fba823529e38
       uri: https://huggingface.co/ChuckMcSneed/FLUX.1-dev/resolve/main/ae.safetensors
+- name: ideogram-4-iq4nl-ggml
+  url: "github:mudler/LocalAI/gallery/virtual.yaml@master"
+  urls:
+    - https://huggingface.co/ideogram-ai/ideogram-4-fp8
+    - https://huggingface.co/stduhpf/ideogram-4-gguf
+  description: |
+    Ideogram 4 is a text-to-image diffusion model known for state-of-the-art prompt adherence and exceptional, accurate text rendering inside images. It is driven by a Qwen3-VL-8B text encoder and performs real classifier-free guidance from a separate unconditional diffusion model.
+
+    This is the iQ4_NL (4-bit) quantization, a good balance of quality and footprint (~5.8GB diffusion + ~5.8GB unconditional). The bundle also pulls the Qwen3-VL-8B-Instruct text encoder and the FLUX.2 VAE. Quantized GGUF weights by stduhpf for use with stable-diffusion.cpp.
+  license: ideogram-non-commercial-model-agreement
+  tags:
+    - ideogram
+    - ideogram4
+    - text-to-image
+    - image-generation
+    - gguf
+    - quantized
+    - 8b
+    - diffusion
+  last_checked: "2026-06-06"
+  overrides:
+    backend: stablediffusion-ggml
+    step: 25
+    # Ideogram4 runs real classifier-free guidance from a separate
+    # unconditional diffusion model, so it needs a CFG scale > 1 (unlike the
+    # guidance-distilled Flux / Z-Image models). 7 matches the upstream
+    # stable-diffusion.cpp default used in the Ideogram4 example.
+    cfg_scale: 7
+    options:
+      - diffusion_model
+      - uncond_diffusion_model_path:ideogram4_unconditional-iQ4_NL.gguf
+      - llm_path:Qwen3-VL-8B-Instruct-Q4_K_M.gguf
+      - vae_path:flux2-vae.safetensors
+      - sampler:euler
+      - offload_params_to_cpu:true
+    parameters:
+      model: ideogram4-iQ4_NL.gguf
+  files:
+    - filename: ideogram4-iQ4_NL.gguf
+      sha256: 578502024f23e8e988e0cb297201f1ac88dddad5706726ad222d918727e0211d
+      uri: huggingface://stduhpf/ideogram-4-gguf/ideogram4-iQ4_NL.gguf
+    - filename: ideogram4_unconditional-iQ4_NL.gguf
+      sha256: 4140e58c6818dac8221fa590a6814246b5336bb23246fbbb96b9048e887f47cf
+      uri: huggingface://stduhpf/ideogram-4-gguf/ideogram4_unconditional-iQ4_NL.gguf
+    - filename: Qwen3-VL-8B-Instruct-Q4_K_M.gguf
+      sha256: 108e7ff92b78eefd3db4741885104acba514255c11b617d3c7b197a5f46efe89
+      uri: huggingface://unsloth/Qwen3-VL-8B-Instruct-GGUF/Qwen3-VL-8B-Instruct-Q4_K_M.gguf
+    - filename: flux2-vae.safetensors
+      sha256: 868fe7b343cc8f3a19dbcfcafbc3d5f888802be3f89bd81b65b3621a066ce8f3
+      uri: https://huggingface.co/Comfy-Org/Ideogram-4/resolve/main/vae/flux2-vae.safetensors
+- name: ideogram-4-q8_0-ggml
+  url: "github:mudler/LocalAI/gallery/virtual.yaml@master"
+  urls:
+    - https://huggingface.co/ideogram-ai/ideogram-4-fp8
+    - https://huggingface.co/stduhpf/ideogram-4-gguf
+  description: |
+    Ideogram 4 is a text-to-image diffusion model known for state-of-the-art prompt adherence and exceptional, accurate text rendering inside images. It is driven by a Qwen3-VL-8B text encoder and performs real classifier-free guidance from a separate unconditional diffusion model.
+
+    This is the Q8_0 (8-bit) quantization for highest quality (~10.1GB diffusion + ~10.1GB unconditional). The bundle also pulls the Qwen3-VL-8B-Instruct text encoder and the FLUX.2 VAE. Quantized GGUF weights by stduhpf for use with stable-diffusion.cpp.
+  license: ideogram-non-commercial-model-agreement
+  tags:
+    - ideogram
+    - ideogram4
+    - text-to-image
+    - image-generation
+    - gguf
+    - quantized
+    - 8b
+    - diffusion
+  last_checked: "2026-06-06"
+  overrides:
+    backend: stablediffusion-ggml
+    step: 25
+    # Ideogram4 runs real classifier-free guidance from a separate
+    # unconditional diffusion model, so it needs a CFG scale > 1 (unlike the
+    # guidance-distilled Flux / Z-Image models). 7 matches the upstream
+    # stable-diffusion.cpp default used in the Ideogram4 example.
+    cfg_scale: 7
+    options:
+      - diffusion_model
+      - uncond_diffusion_model_path:ideogram4_unconditional-Q8_0.gguf
+      - llm_path:Qwen3-VL-8B-Instruct-Q4_K_M.gguf
+      - vae_path:flux2-vae.safetensors
+      - sampler:euler
+      - offload_params_to_cpu:true
+    parameters:
+      model: ideogram4-Q8_0.gguf
+  files:
+    - filename: ideogram4-Q8_0.gguf
+      sha256: feb6cae997927ba0e339bf6ef64b14df9353064f60805d53f84c592643addcfd
+      uri: huggingface://stduhpf/ideogram-4-gguf/ideogram4-Q8_0.gguf
+    - filename: ideogram4_unconditional-Q8_0.gguf
+      sha256: 9261d1473d328aa7edbe1b3fa48a9b9bd2e19fe78439fe6a293af1016c63debd
+      uri: huggingface://stduhpf/ideogram-4-gguf/ideogram4_unconditional-Q8_0.gguf
+    - filename: Qwen3-VL-8B-Instruct-Q4_K_M.gguf
+      sha256: 108e7ff92b78eefd3db4741885104acba514255c11b617d3c7b197a5f46efe89
+      uri: huggingface://unsloth/Qwen3-VL-8B-Instruct-GGUF/Qwen3-VL-8B-Instruct-Q4_K_M.gguf
+    - filename: flux2-vae.safetensors
+      sha256: 868fe7b343cc8f3a19dbcfcafbc3d5f888802be3f89bd81b65b3621a066ce8f3
+      uri: https://huggingface.co/Comfy-Org/Ideogram-4/resolve/main/vae/flux2-vae.safetensors
 - name: whisper-1
   url: github:mudler/LocalAI/gallery/whisper-base.yaml@master
   urls: