ComfyUI Node: 8-Bit / Pixelate | GlitchNodes

8-Bit / Pixelate | GlitchNodes:

The Pixel8Bit node is designed to transform images into an 8-bit or retro aesthetic, reminiscent of classic video game graphics. This node offers a variety of techniques to achieve this look, including pixelation, palette quantization, and dithering. Pixelation reduces the image resolution to create a blocky, pixelated effect. Palette quantization allows you to limit the colors in the image to a fixed set, either from a predefined palette like PICO-8 or Game Boy, or through adaptive methods like K-Means clustering. Dithering techniques, such as Ordered or Floyd-Steinberg, are used to simulate additional colors and gradients by strategically placing pixels. This node is particularly useful for artists looking to create nostalgic or stylistically retro visuals, providing a wide range of customization options to tailor the output to specific artistic needs.

8-Bit / Pixelate | GlitchNodes Input Parameters:

IMAGE

This parameter expects an image in the form of a torch tensor with a shape of [B, H, W, C], where B is the batch size, H is the height, W is the width, and C is the number of color channels. The image should be in float32 format with values ranging from 0 to 1. This input serves as the base image that will be transformed into an 8-bit style.

pixel_size

This integer parameter controls the level of pixelation applied to the image. A larger pixel size results in a more pronounced pixelated effect. The value can range from 1 to 256, with a default of 4. Adjusting this parameter allows you to fine-tune the blockiness of the image.

quant_mode

This parameter determines the method of palette quantization. You can choose between "Fixed Palette" and "Adaptive K-Means". "Fixed Palette" uses a predefined set of colors, while "Adaptive K-Means" dynamically selects colors based on the image content. This choice affects how colors are reduced in the image.

fixed_palette

When using the "Fixed Palette" quantization mode, this parameter specifies which predefined color palette to use. Options include "PICO-8", "GameBoy", "NES", "C64", "ZX Spectrum", "Apple II", "EGA-16", "VGA-256", "Amiga-Workbench", "Atari2600-Subset", "MSX", "CGA-Default", "CGA-Alternate", and "Custom". Each palette offers a unique set of colors that can dramatically change the image's appearance.

custom_palette_hex

If "Custom" is selected as the fixed palette, this string parameter allows you to define your own color palette using hexadecimal color codes. The default value is "#000000,#555555,#AAAAAA,#FFFFFF". This option provides flexibility to create a personalized color scheme.

k_colors

This integer parameter is relevant when using the "Adaptive K-Means" quantization mode. It specifies the number of colors to be used in the palette, ranging from 2 to 256, with a default of 8. This setting influences the diversity of colors in the final image.

dithering

This parameter determines the dithering technique applied to the image. Options include "None", "Ordered", and "Floyd-Steinberg". Dithering helps to create the illusion of more colors and smoother gradients by varying the placement of pixels.

ordered_size

When "Ordered" dithering is selected, this integer parameter specifies the size of the Bayer matrix used for dithering. It can range from 2 to 8, with a default of 4. This setting affects the pattern and intensity of the dithering effect.

posterize_bits

This integer parameter controls the level of posterization applied to the image, which reduces the number of bits used per color channel. It ranges from 1 to 8, with a default of 8. Lower values result in fewer colors and a more stylized look.

gamma

This float parameter adjusts the gamma correction applied to the image, affecting its brightness and contrast. It ranges from 0.1 to 3.0, with a default of 1.0. Adjusting gamma can enhance or soften the visual impact of the 8-bit transformation.

8-Bit / Pixelate | GlitchNodes Output Parameters:

IMAGE

The output is an image tensor with the same shape as the input [B, H, W, C], but transformed to exhibit an 8-bit or retro aesthetic. This output reflects the combined effects of pixelation, palette quantization, and dithering, providing a stylized version of the original image suitable for artistic or nostalgic purposes.

8-Bit / Pixelate | GlitchNodes Usage Tips:

• Experiment with different fixed palettes to achieve various retro styles, such as using "PICO-8" for a vibrant, colorful look or "GameBoy" for a monochromatic effect.
• Use a larger pixel size for a more pronounced pixelated effect, which can be particularly effective for creating a vintage video game aesthetic.
• Adjust the gamma setting to fine-tune the brightness and contrast of the final image, enhancing the visual impact of the 8-bit transformation.
• When using "Adaptive K-Means" quantization, try different values for k_colors to balance between color diversity and simplicity in the image.

8-Bit / Pixelate | GlitchNodes Common Errors and Solutions:

"IMAGE must be a torch.Tensor"

• Explanation: The input image is not provided as a torch tensor, which is required for processing.
• Solution: Ensure that the input image is converted to a torch tensor before passing it to the node.

"Expected IMAGE tensor of shape [B,H,W,C], got (shape)"

• Explanation: The input image does not have the correct shape, which should be [B, H, W, C].
• Solution: Verify that the input image is reshaped to the required dimensions before processing.

"Invalid palette name or custom hex format"

• Explanation: The specified palette name is not recognized, or the custom hex string is incorrectly formatted.
• Solution: Check the palette name for typos or ensure the custom hex string is a comma-separated list of valid hexadecimal color codes.