/**
 * Options for configuring image source validation behavior.
 */
export interface IsImageSrcOptions {
    /**
     * List of supported image file extensions. If provided, only URLs with these extensions are considered valid.
     * Extensions should be specified with leading dots (e.g., '.jpg', '.png').
     *
     * @defaultValue A comprehensive list of common image extensions
     */
    supportedExtensions?: string[];
}
/**
 * Checks if the provided source is a valid image source.
 *
 * This function verifies whether the input `src` is a valid image source by performing
 * several checks:
 *
 * 1. **Non-null String Check**: It first checks if `src` is a non-null string using the
 *    `isNonNullString` function.
 *
 * 2. **Trim Whitespace**: The function trims any leading or trailing whitespace from the
 *    source string to ensure accurate validation.
 *
 * 3. **Blob URL Handling**: If the source starts with `blob:http`, it removes the `blob:`
 *    prefix for further validation. Note that `ltrim` should be defined elsewhere in your code.
 *
 * 4. **Validation Checks**: The function then checks if the modified source is:
 *    - A valid data URL using the `isDataUrl` function.
 *    - A string that matches supported image file extensions.
 *
 * The function returns `true` if any of these conditions are met, indicating that the source
 * is a valid image source; otherwise, it returns `false`.
 *
 * @param {any} src - The source to validate as an image source.
 * @param {IsImageSrcOptions} options - Optional configuration for validation behavior.
 * @returns {boolean} - Returns `true` if the source is a valid image source,
 *                      `false` otherwise.
 *
 * @example
 * // Valid image sources with default extensions
 * console.log(isImageSrc('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA...')); // true
 * console.log(isImageSrc('https://example.com/image.jpg')); // true
 * console.log(isImageSrc('image.png')); // true (if file extension is valid)
 *
 * // With custom supported extensions
 * console.log(isImageSrc('image.webp', { supportedExtensions: ['.jpg', '.png'] })); // false
 * console.log(isImageSrc('image.jpg', { supportedExtensions: ['.jpg', '.png'] })); // true
 *
 * // Invalid image sources
 * console.log(isImageSrc(null)); // false
 * console.log(isImageSrc('')); // false
 * console.log(isImageSrc('not-a-valid-url')); // false
 * console.log(isImageSrc('blob:http://example.com/...')); // true (if valid blob URL)
 */
export declare const isImageSrc: (src: string | null | undefined, options?: IsImageSrcOptions) => boolean;