Image Conversion

Master ComfyUI's image conversion! This guide enhances Image-To-Image with precise control, facial referencing, and high-definition upscaling.

ComfyUI Image Conversion - Before and After

Thinking Process:

Comfyui's Image conversion is similar to webui's Img2Img, where an original image is uploaded and its style is modified through the model. However, to enhance the precision of the conversion, we can add a few new steps:

I. Add a model magnification node to control the size of the original image.

II. Increase similarity to the original image:

a. Use ipadapter faceid to reference facial features.

b. Reverse-engineer the original image prompts.

c. Add ControlNet (openpose, canny, depth).

III. Upscale the final Image

ComfyUI Image Conversion Process

Step 1: Build the Model Group

We can start building on the basis of the Img2Img template. First, selectively add an "Upscale Image By" node behind the original image to control the size of the original image. Lora can be added according to individual needs, or not added at all. Add a "CLIP Set Last Layer" node according to your needs, which can also be omitted. This node allows skipping of layers, and finally, connect the corresponding nodes.

ComfyUI Image Conversion - Build the Model Group

Add nodes:

Upscale Image By

CLIP Set Last Layer

Step 2: Reference the Original Image

(Reverse-engineer prompts + Ipadapter + Control Net)

  1. Reverse-engineer prompts: WD14 Tagger node

Double-click to search and add the WD14 Tagger node.

Connect the image node.

Right-click on the positive prompts node and select "Convert text to input" to connect the WD14 Tagger to the positive prompts node.

ComfyUI Image Conversion - BReverse-engineer Prompts: WD14 Tagger Node 1

However, this only includes the prompts from the image. If you want to add other prompts, You need to create a new Text Concatenate node, which can connect multiple segments of prompts together.

Then create a new Primitive node. The Primitive node can be connected to any node to become a related attribute.

Enter additional prompts on the Primitive, such as Lora Trigger Words, some quality words, etc.

ComfyUI Image Conversion - BReverse-engineer Prompts: WD14 Tagger Node 2
ComfyUI Image Conversion - BReverse-engineer Prompts: WD14 Tagger Node 3

At this point, the prompts not only include the ones reverse-engineered from the image but also those we input.

  1. Next, set up the IPadapter FaceID to reference facial features:

Double-click to search for IPadapter FaceID and match the input nodes accordingly.

ComfyUI Image Conversion - Set up the IPadapter FaceID to Reference Facial Features

After dragging out the node, create new nodes:

ipadapter→ IPAdapter Model Loader

clip_vision→ Load CLIP Vision

insightface→ IPAdapter InsightFace Loader

Connect the output to the sampler.

Add nodes:

IPadapter FaceID

IPAdapter Model Loader

Load CLIP Vision

IPAdapter InsightFace Loader

  1. Set up the ControlNet

It is recommended to use the CR Multi-ControlNet Stack node, which allows the addition of multiple ControlNets. Then add the corresponding preprocessors. It is recommended to use OpenPose, Canny, and Depth as the ControlNet. You can add or remove them based on the final visual needs. Afterwards, add a ControlNet application node at the output: CR Apply Multi-ControlNet. It is recommended to set the resolution at the preprocessor to 1024.

*Finally, remember to turn on the switches of the ControlNet that will be used.

ComfyUI Image Conversion - Set up the ControlNet

Input:

Connected to the positive and negative prompt nodes.

Output:

Connected to the sampler.

Add nodes:

CR Multi-ControlNet Stack

CR Apply Multi-ControlNet

Step 3: High-Definition Restoration

After the model group and reference to the original image have been set up, we can add an image high-definition restoration step at the final output of the image:

ComfyUI Image Conversion - High-Definition Restoration

Add Nodes: Upscale Image (using Model)

After assembling the nodes, you can organize them into a group for easier viewing.

ComfyUI Image Conversion - Add Nodes to Upscale Image 1
ComfyUI Image Conversion - Add Nodes to Upscale Image 2

Finally, it's necessary to adjust the relevant parameters based on the output image, such as ckpt, Lora weights, prompt words, sampler, redraw scale, etc.

Key parameters for this conversion include:

CLIP _layer:-2

Upscale Image By: 1.5

steps: 40

sampler_name: dpmpp_2m

scheduler: karras

denoise: 0.7

Note: If you choose the SDXL model, you will also need the corresponding SDXL Lora, and adjust the ControlNet to SDXL; otherwise, the image output will fail.

ComfyUI Image Conversion - Corresponding SDXL Lora

The above is a complete workflow for image conversion. Based on this, you can also add VAE or FreeU_V2 to adjust the final image:

FreeU_V2: Mainly controls color and extracts some content for optimization.

Load VAE: Fine-tunes the color and details of the image.

Adjust Image with VAE or FreeU_V2 - Before and After
ComfyUI Image Conversion - Adjust Image with VAE or FreeU_V2

Through such a workflow, you can achieve conversions to different styles.

ComfyUI Image Conversion - Various Styles

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