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#lang racket/base
;;; Portions Copyright (C) 2012 Jose Antonio Ortega Ruiz.
(require file/convertible
racket/file
racket/vector)
(provide convert-image?
convert-image)
;; save-temporary-image : bytes? -> string?
;;
;; Write bytes to a temporary file and return "#<Image: filename>".
(define (save-temporary-image png-bytes)
(define filename (make-temporary-file "racket-image-~a.png"))
(with-output-to-file filename #:exists 'truncate
(λ () (display png-bytes)))
(format "#<Image: ~a>" filename))
(define (convert-image? v)
(convertible? v))
(define (convert-image v)
(cond [(and (convertible? v) (convert v 'png-bytes)) => save-temporary-image]
[else v]))
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