ComfyUI Node: Image Levels Adjustment

Image Levels Adjustment:

The Image Levels Adjustment node is designed to enhance the visual quality of your images by adjusting the brightness levels across different tonal ranges. This node allows you to fine-tune the minimum, mid, and maximum levels of your image, ensuring that the darkest and brightest parts of the image are appropriately balanced. By manipulating these levels, you can improve the contrast and overall appearance of your images, making them more visually appealing. This adjustment is particularly useful for correcting underexposed or overexposed images, bringing out details in shadows and highlights, and achieving a more balanced and professional look.

Image Levels Adjustment Input Parameters:

min_level

The min_level parameter sets the minimum brightness level for the image. Pixels with brightness values below this threshold will be set to this minimum level, effectively lifting the darkest parts of the image. This adjustment helps in revealing details in the shadow areas. The value should be an integer between 0 and 255, with a default value typically set to 0.

mid_level

The mid_level parameter adjusts the mid-tone brightness of the image. This parameter is used to control the gamma correction, affecting the overall brightness and contrast of the mid-tones without altering the darkest and brightest parts significantly. The value should be an integer between 0 and 255, with a default value typically set to 128.

max_level

The max_level parameter sets the maximum brightness level for the image. Pixels with brightness values above this threshold will be set to this maximum level, effectively compressing the brightest parts of the image. This adjustment helps in preventing overexposure and retaining details in the highlights. The value should be an integer between 0 and 255, with a default value typically set to 255.

Image Levels Adjustment Output Parameters:

image

The output parameter image is the adjusted image with the applied levels correction. This image will have enhanced contrast and balanced brightness levels, making it more visually appealing and detailed. The output is typically in the same format as the input image, ensuring compatibility with subsequent processing steps.

Image Levels Adjustment Usage Tips:

• To enhance details in shadow areas, increase the min_level slightly above 0.
• For a more balanced image, adjust the mid_level to control the overall brightness and contrast.
• To prevent overexposure, reduce the max_level slightly below 255. - Experiment with different combinations of min_level, mid_level, and max_level to achieve the desired visual effect.

Image Levels Adjustment Common Errors and Solutions:

Image appears too dark or too bright

• Explanation: This issue occurs when the min_level, mid_level, or max_level parameters are not set correctly, leading to an imbalance in brightness levels.
• Solution: Adjust the min_level, mid_level, and max_level parameters incrementally to find the right balance. Start with default values and make small adjustments.

Loss of detail in shadows or highlights

• Explanation: Setting the min_level too high or the max_level too low can result in loss of detail in the shadow or highlight areas, respectively.
• Solution: Ensure that the min_level is not set too high and the max_level is not set too low. Adjust these parameters to retain details in both shadows and highlights.

Image looks washed out

• Explanation: This can happen if the mid_level is set too high, causing the mid-tones to be overly brightened.
• Solution: Lower the mid_level to bring back the contrast in the mid-tones and achieve a more natural look.

Image has too much contrast

• Explanation: Excessive contrast can occur if the min_level is set too low and the max_level is set too high.
• Solution: Adjust the min_level and max_level to reduce the contrast and achieve a more balanced image.