The docs for make-argb read: Constructs a new argb value. The vector has four entries for each pixel, an alpha, red, green, and blue value. The int specifies the width of the image; the height is the size of the vector, divided by 4, divided by the width.
This documentation doesn't specify whether the mapping from vector to coordinate is in row-major or column-major order. t propose adding a sentence to clarify: Constructs a new argb value. The vector has four entries for each pixel, an alpha, red, green, and blue value. The int specifies the width of the image; the height is the size of the vector, divided by 4, divided by the width. The values for pixel (x,y) are taken starting at position (y*width+x)*4 in the vector. Maybe you can do better? John
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