PRO SHOWIMAGE, FILE, DITHER=DITHER, CURRENT=CURRENT ;+ ; NAME: ; SHOWIMAGE ; ; PURPOSE: ; Show the contents of a graphics file in the current window. ; ; The input formats supported are: ; GIF 8-bit with color table, ; BMP 8-bit with color table or 24-bit true-color, ; PICT 8-bit with color table, ; TIFF 8-bit with color table or 24-bit true-color, ; JPEG 24-bit true color, ; ; Any conversions necessary to translate 8-bit or 24-bit files ; to 8-bit or 24-bit images on-screen are done automatically. ; ; CATEGORY: ; Input/Output. ; ; CALLING SEQUENCE: ; SHOWIMAGE, FILE ; ; INPUTS: ; FILE Name of the output file (format is identified automatically). ; ; OPTIONAL INPUTS: ; None. ; ; KEYWORD PARAMETERS: ; DITHER Set this keyword to dither the input image when displaying ; 24-bit images on an 8-bit display (default is no dithering). ; CURRENT Set this keyword to display the image in the current window ; (default is to create a new window sized to fit the image). ; ; OUTPUTS: ; None. ; ; OPTIONAL OUTPUTS: ; None ; ; COMMON BLOCKS: ; None ; ; SIDE EFFECTS: ; The color table is modified. ; ; RESTRICTIONS: ; Requires IDL 5.2 or higher (image QUERY functions). ; ; EXAMPLE: ; ;showimage, filepath('rose.jpg', subdir='examples/data') ; ; MODIFICATION HISTORY: ; Liam.Gumley@ssec.wisc.edu ; http://cimss.ssec.wisc.edu/~gumley ; $Id: showimage.pro,v 1.15 1999/11/19 21:20:50 gumley Exp $ ; ; Copyright (C) 1999 Liam E. Gumley ; ; This program is free software; you can redistribute it and/or ; modify it under the terms of the GNU General Public License ; as published by the Free Software Foundation; either version 2 ; of the License, or (at your option) any later version. ; ; This program is distributed in the hope that it will be useful, ; but WITHOUT ANY WARRANTY; without even the implied warranty of ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ; GNU General Public License for more details. ; ; You should have received a copy of the GNU General Public License ; along with this program; if not, write to the Free Software ; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ;- rcs_id = '$Id: showimage.pro,v 1.15 1999/11/19 21:20:50 gumley Exp $' ;------------------------------------------------------------------------------- ;- CHECK INPUT ;------------------------------------------------------------------------------- ;- Check IDL version if float(!version.release) lt 5.2 then begin message, 'IDL 5.2 or higher is required', /continue return endif ;- Check input arguments case 1 of n_params() ne 1 : error = 'Usage: SHOWIMAGE, FILE' n_elements(file) eq 0 : error = 'Argument FILE is undefined' n_elements(file) gt 1 : error = 'Argument FILE must be a scalar string' (findfile(file))[0] eq '' : error = 'Argument FILE was not found' else : error = '' endcase if error ne '' then begin message, error, /continue return endif ;------------------------------------------------------------------------------- ;- CHECK THE GRAPHICS DEVICE ;------------------------------------------------------------------------------- ;- Check for device supporting windows and tvrd() if ((!d.flags and 256) eq 0) or ((!d.flags and 128) eq 0) then begin error = string(!d.name, format='("Graphics device (",a,") is not supported")') message, error, /continue return endif ;- Make sure a window has been opened in this session and get visual depth if !d.window lt 0 then begin window, /free, /pixmap, xsize=20, ysize=20 wdelete, !d.window endif device, get_visual_depth=depth ;- If 8-bit display is low on colors, print a message if (depth eq 8) and (!d.table_size) lt 64 then message, $ 'Display has less than 64 colors; image quality may degrade', /continue ;------------------------------------------------------------------------------- ;- IDENTIFY FILE AND READ IMAGE ;------------------------------------------------------------------------------- ;- Identify the file format result = query_gif(file, info) if result eq 0 then result = query_bmp(file, info) if result eq 0 then result = query_pict(file, info) if result eq 0 then result = query_tiff(file, info) if result eq 0 then result = query_jpeg(file, info) if result eq 0 then begin message, 'File format not recognized', /continue return endif ;- Fix the channel information for GIF images if info.type eq 'GIF' then info.channels = 1 ;- Read the image case info.type of 'GIF' : read_gif, file, image, r, g, b 'BMP' : begin if info.channels eq 1 then begin image = read_bmp(file, r, g, b) endif else begin image = read_bmp(file) image = reverse(temporary(image), 1) endelse end 'PICT' : read_pict, file, image, r, g, b 'TIFF' : begin if info.channels eq 1 then begin image = read_tiff(file, r, g, b, order=order) image = reverse(temporary(image), 2) endif else begin image = read_tiff(file, order=order) image = reverse(temporary(image), 3) endelse end 'JPEG' : read_jpeg, file, image endcase ;- If an 8-bit image was read, reduce the number of colors if info.channels eq 1 then begin reduce_colors, image, index r = r[index] g = g[index] b = b[index] endif ;- Get image size dims = size(image, /dimensions) if n_elements(dims) eq 2 then begin nx = dims[0] ny = dims[1] endif else begin nx = dims[1] ny = dims[2] endelse ;------------------------------------------------------------------------------- ;- CREATE A WINDOW ;------------------------------------------------------------------------------- ;- Create a draw widget sized to fit the image if not keyword_set(current) then begin ;- Set default window size scroll = 0 xsize = nx ysize = ny draw_xsize = nx draw_ysize = ny ;- Adjust the window size if the image is too large device, get_screen_size=screen if nx gt (0.95 * screen[0]) then begin xsize = 0.85 * nx scroll = 1 endif if ny gt (0.95 * screen[1]) then begin ysize = 0.85 * ny scroll = 1 endif ;- Create the draw widget base = widget_base(title=file) draw = widget_draw(base, scroll=scroll) widget_control, draw, xsize=xsize, ysize=ysize, $ draw_xsize=draw_xsize, draw_ysize=draw_ysize endif ;------------------------------------------------------------------------------- ;- HANDLE IDL 8-BIT MODE ;------------------------------------------------------------------------------- if depth eq 8 then begin ;- If the color table of an 8-bit image is larger than ;- the current display table, convert the image to 24-bit if (info.channels eq 1) and (n_elements(r) gt !d.table_size) then begin ;- Convert to 24-bit dims = size(image, /dimensions) nx = dims[0] ny = dims[1] true = bytarr(3, nx, ny) true[0, *, *] = r[image] true[1, *, *] = g[image] true[2, *, *] = b[image] image = temporary(true) ;- Reset the number of channels info.channels = 3 endif ;- If image is 24-bit, convert to 8-bit if info.channels eq 3 then begin ;- Convert 24-bit image to 8-bit image = color_quan(image, 1, r, g, b, colors=!d.table_size, $ dither=keyword_set(dither)) ;- Sort the color table from darkest to brightest table_sum = total([[long(r)], [long(g)], [long(b)]], 2) table_index = sort(table_sum) image_index = sort(table_index) r = r[table_index] g = g[table_index] b = b[table_index] oldimage = image image[*] = image_index[temporary(oldimage)] ;- Reset the number of channels info.channels = 1 endif endif ;------------------------------------------------------------------------------- ;- DISPLAY THE IMAGE ;------------------------------------------------------------------------------- ;- Realize the draw widget if not keyword_set(current) then widget_control, base, /realize ;- Save current decomposed mode and display order device, get_decomposed=current_decomposed current_order = !order ;- Set image to display from bottom up !order = 0 ;- Display the image if info.channels eq 1 then begin device, decomposed=0 tvlct, r, g, b tv, image endif else begin device, decomposed=1 tv, image, true=1 endelse ;- Restore decomposed mode and display order device, decomposed=current_decomposed !order = current_order END