Display JPEG image from POST request in *image-output* buffer

test.el

(defvar server)
(progn
  (delete-process server)
  (let ((coding-system-for-read 'binary))
    (setq server
          (make-network-process
           :name "image-server"
           :buffer "*image-server*"
           :family 'ipv4
           :service 9009
           :sentinel 'image-server-sentinel
           :filter 'image-server-filter
           :coding 'binary
           :server 't)))
  )

(defun image-server-sentinel (proc msg)
  (let ((buffer-name (concat " *image-server-" (process-name proc) "*")))
    (if (string-match "^open" msg)
        (process-put
         proc
         'buffer
         (with-current-buffer (get-buffer-create buffer-name)
           (erase-buffer)
           (toggle-enable-multibyte-characters -1)
           (current-buffer)))
      (progn (kill-buffer (get-buffer-create buffer-name))
             (with-current-buffer (get-buffer-create "*image-output*")
               (let ((img (create-image (process-get proc 'payload) 'jpeg t)))
                 (insert-image img)))))))

(defun image-server-filter (proc string)
  (with-current-buffer (process-get proc 'buffer)
    (insert string)
    (save-excursion
      (goto-char (point-min))
      (cond
       ((not (process-get proc 'boundary))
        (let ((point (search-forward-regexp "\r\n\r\n" nil t 1)))
          (when point
            (process-put proc 'boundary point)
            (goto-char (point-min))
            (search-forward "Content-Length: " point nil 1)
            (process-put proc
                         'content-length
                         (string-to-number (buffer-substring (point) (line-end-position)))))))
       (t
        (let ((boundary (process-get proc 'boundary))
              (content-length (process-get proc 'content-length)))
          (when (>= (point-max) (+ boundary content-length))
            (process-put proc 'payload
                         (buffer-substring-no-properties boundary content-length))
            (delete-process proc))))))))

(provide 'test)