FileUnitTestCase::testImageDimensions in modules/file/tests/file.test

Tests storing image height and width as file metadata.

file_validate_image_orientation in includes/file.inc

Check for EXIF orientation data and rotate file if needed.

file_validate_image_resolution in includes/file.inc

Verifies that image dimensions are within the specified maximum and minimum.

image_style_create_derivative in modules/image/image.module

Creates a new image derivative based on an image style.

ImageToolkitGdTestCase::testManipulations in modules/simpletest/tests/image.test

Since PHP can't visually check that our images have been manipulated properly, build a list of expected color values for each of the corners and the expected height and widths for the final images.

ImageToolkitUnitTest::testSave in modules/simpletest/tests/image.test

Test the image_save() function.