Fix incorrect width ratio calculation in Llama4 image processor

[Jingxiang-Zhang]

In the Llama4ImageProcessorFast class (source), the image resizing ratios for height and width are incorrectly calculated using the image height for both dimensions:

ratio_h, ratio_w = (
    target_size[0] // size.height,
    target_size[1] // size.height,
)

Here, size is defined as:

size = {"height": 336, "width": 336}

This configuration is also present in the preprocessor_config.json:

"size": {
  "height": 336,
  "width": 336
}

Currently, the bug does not cause visible issues because the height and width are equal. However, this would lead to incorrect behavior if the dimensions were different.

Suggested Fix:
Update the width ratio calculation to use size.width instead of size.height:

ratio_h, ratio_w = (
    target_size[0] // size.height,
    target_size[1] // size.width,
)

This change ensures correct aspect ratio handling in cases where the input size is not square.

[Rocketknight1]

cc @qubvel @zucchini-nlp

[qubvel]

Thanks for fixing @Jingxiang-Zhang, looks indeed like a bug 👍

cc @yonigozlan for fast image processors

[yonigozlan]

Thanks for fixing! Typo indeed

[HuggingFaceDocBuilderDev]

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