Working with Image Data and ImageTexture in the Blender Python API

What will you learn in this guide?

Learn how to create an Image data block with the Blender Python API, scale its image buffer, and change pixel values. We’ll also look at the role of update() in making edits visible in the image, and what to keep in mind about the buffer when copying an Image data block. Finally, we’ll cover how ImageTexture options relate to tiling, alpha, and image boundaries.

This guide is for architectural visualization teams and Blender users who want to prepare image data with scripts or examine texture behavior more closely. The examples are limited to operations described in the API documentation; assigning materials to a scene and setting up a node network are outside its scope.

Requirements

• Access to the Python API in Blender is required. The sources are Blender’s current API documentation; these pages do not specify the minimum Blender version required for the operations described.

• The code examples use the bpy module in Blender’s Python environment. The sources do not mention any external account requirements.

• The API documentation does not provide hardware requirements, fees, or licensing costs for these operations. Do not assume specific requirements; check the version and working environment you plan to use separately.

Step by step: Work with an Image data block

1. Create an image data block

You can create a new Image data block with bpy.data.images.new(). The example below uses the starting dimensions shown in the source document. The size property lets you read the image buffer’s width and height in pixels.

import bpy

image_src = bpy.data.images.new("Mimari_Kontrol", 1024, 102)
print(image_src.size)

An Image data block should not be thought of as holding all the image’s data itself. The documentation says that information such as the pixel buffer and dimensions is stored in an image buffer, while the Image data block references an image file or a generated image. This distinction matters, especially when you edit the buffer and then copy the data block.

2. Scale the buffer and apply the changes to the image

scale() changes the size of the image buffer. The pixels property provides access to the pixel buffer, which consists of floating-point values. The example below scales the image to 1024 × 720, changes the first four buffer values, and then updates the image.

image_src.scale(1024, 720)
image_src.pixels[0:4] = (0.5, 0.5, 0.5, 0.5)
image_src.update()

print(image_src.size)
print(image_src.pixels[0:4])

This code only assigns values to the first four buffer entries; it does not fill the entire image. Calling update() refreshes the displayed image to reflect edits made to the floating-point buffer. If the result is unexpected, first check that the variable points to the correct Image data block and that the update call has run.

3. Check the copy behavior

Copying an Image data block does not necessarily mean that buffer changes are copied automatically. The documentation cautions that buffers are not shared between different Image data blocks and are not duplicated when an image is copied. As a result, buffer edits that have not been saved to disk may not be present in the copy.

image_dest = image_src.copy()
image_dest.update()

print(image_dest.size)
print(image_dest.pixels[0:4])

After creating the copy, check its dimensions and buffer values separately. Don’t assume it will contain the latest edits made to the source image. If buffer changes need to appear in the copy, consider whether you need to save the image to disk first, then verify the copy.

4. Save the image or pack it into the project file

The Image API provides save() to save an image and save_render() to save it to a specific path using the scene’s render settings. pack() can be used to embed the image as data in the .blend file.

image_src.pack()

Packing, saving, and reloading are different operations. In the API, unpack() extracts a packed image to disk, while reload() loads the image again from its source path. The right method depends on how you want to manage the image’s file path and data in the project. Before delivery, check that the image is in the expected location and confirm its status in the project file.

How to choose ImageTexture settings

ImageTexture options determine how an image is handled as a texture. The extension property selects the behavior outside the image’s own boundaries. REPEAT tiles the image horizontally and vertically; EXTEND extends the edge pixels; CLIP leaves the area outside the image dimensions transparent. The documentation also lists CLIP_CUBE and CHECKER as options.

repeat_x and repeat_y set the horizontal and vertical repeat factors separately. For alpha, there are use_alpha and invert_alpha to invert alpha values. use_interpolation controls interpolation, while filter_size affects the filter size used for interpolation. When reviewing these settings, consider the source image’s alpha channel and how the texture will be used.

The Image API lists STRAIGHT, PREMUL, CHANNEL_PACKED, and NONE as alpha modes. The documentation describes CHANNEL_PACKED as a use case where different images are packed into the RGB and alpha channels, which should not affect one another. If you don’t know how the source file’s channels are arranged, check how the image was prepared before changing its alpha settings.

Common mistakes

• Assuming the buffer is copied too: Unsaved changes may not appear in the copy. Check the copy’s dimensions and buffer values.

• Forgetting to call update() after editing: Update the image after making changes to the buffer.

• Not checking behavior at texture boundaries: REPEAT, EXTEND, and CLIP produce different results. Decide how the image edges should behave.

• Changing alpha settings without considering the source image: Confirm whether the alpha channel is used and which alpha mode is appropriate.

• Treating saving and packing as the same operation: save(), pack(), unpack(), and reload() serve different purposes. Check the image state in the project file and on disk separately.

Next steps

Try the operations in a small test file first. After creating the image, print its dimensions; after scaling it and changing pixel values, update the buffer and inspect the values again. When testing copy behavior, compare the source and copy values. Then try boundary behavior and tiling settings for ImageTexture in a controlled way. Before moving to an architectural visualization scene, check the source image’s file path, alpha usage, and whether it should be packed into the project.

Source and license

This guide is based on the bpy.types.Image and bpy.types.ImageTexture pages in Blender’s official Python API documentation. Both sources are licensed under CC BY-SA 4.0; the content has been adapted into Turkish.