;+
; NAME:
; TVREAD
;
; PURPOSE:
;
; To get accurate screen dumps with the IDL command TVRD on 24-bit
; PC and Macintosh computers, you have to be sure to set color
; decomposition on. This program adds that capability automatically.
; In addition, the program will optionally write BMP, GIF, JPEG,
; PICT, PNG, and TIFF color image files of the screen dump.
;
; AUTHOR:
;
; FANNING SOFTWARE CONSULTING
; David Fanning, Ph.D.
; 1645 Sheely Drive
; Fort Collins, CO 80526 USA
; Phone: 970-221-0438
; E-mail: davidf@dfanning.com
; Coyote's Guide to IDL Programming: http://www.dfanning.com
;
; CATEGORY:
;
; Graphics
;
; CALLING SEQUENCE:
;
; image = TVREAD(xstart, ystart, ncols, nrows)
;
; The returned image will be a 2D image on 8-bit systems and
; a 24-bit pixel interleaved true-color image on 24-bit systems.
; A -1 will be returned if a file output keyword is used (e.g., JPEG, TIFF, etc.).
;
; OPTIONAL INPUTS:
;
; XSTART -- The starting column index. By default, 0.
;
; YSTART -- The starting row index. By default, 0.
;
; NCOLS -- The number of columns to read. By default, !D.X_Size - XSTART
;
; NROWS -- The number of rows to read. By default, !D.Y_Size - YSTART.
;
; KEYWORD PARAMETERS:
;
; BMP -- Set this keyword to write the screen dump as a color BMP file.
;
; CANCEL -- An output keyword set to 1 if the user cancels out of a
; filename dialog. Set to 0 otherwise.
;
; COLORS -- If a 24-bit image has to be quantized, this will set the number
; of colors in the output image. Set to 256 by default. Applies to BMP,
; GIF, PICT, and PNG formats written from 24-bit displays.(See the
; COLOR_QUAN documentation for details.)
;
; CUBE -- If this keyword is set to a value between 2 and 6 the color
; quantization will use a cubic method of quantization. Applies to BMP,
; GIF, PICT, and PNG formats written from 24-bit displays.(See the
; COLOR_QUAN documentation for details.)
;
; DITHER -- If this keyword is set the quantized image will be dithered.
; Applies to BMP, GIF, PICT, and PNG formats written from 24-bit displays.
; (See the COLOR_QUAN documentation for details.)
;
; FILENAME -- The base name of the output file. (No file extensions;
; they will be added automatically.) This name may be changed by the user.
;
; image = TVREAD(Filename='myfile', /JPEG)
;
; No file will be written unless a file output keyword is used
; (e.g., JPEG, TIFF, etc.) in the call. By default the FILENAME is
; set to "idl". The file extension will be set automatically to match
; the type of file created.
;
; GIF -- Set this keyword to write the screen dump as a color GIF file.
;
; JPEG -- Set this keyword to write the screen dump as a color JPEG file.
;
; NODIALOG -- Set this keyword if you wish to avoid the DIALOG_PICKFILE
; dialog that asks you to name the output file. This keyword should be
; set, for example, if you are processing screens in batch mode.
;
; ORDER -- Set this keyword to determine the image order for reading the
; display. Corresponds to !Order and set to such as the default.
;
; OVERWRITE_PROMPT -- Set this keyword if you would like to get a prompt
; if you are overwriting a file. This applies only to operations with
; DIALOG_PICKFILE.
;
; PICT -- Set this keyword to write the screen dump as a color PICT file.
;
; PNG -- Set this keyword to write the screen dump as a color PNG file.
;
; TIFF -- Set this keyword to write the screen dump as a color TIFF file.
;
; TRUE -- Set this keyword to the type of interleaving you want. 1 = Pixel
; interleaved, 2 = row interleaved, 3 = band interleaved.
;
; TYPE -- Can be set to the type of file to write. Use this instead of
; setting BMP, GIF, JPEG, PICT, PNG, or TIFF keywords: TYPE='JPEG'. The
; primary purpose of this is to make event handlers easier to write.
;
; QUALITY -- This keyword sets the amount of compression for JPEG images.
; It should be set to a value between 0 and 100. It is set to 75 by default.
; (See the WRITE_JPEG documentation for details.)
;
; WID -- The index number of the window to read from. The current graphics window
; (!D.Window) is selected by default. An error is issued if no windows are
; currently open on a device that supports windows.
;
; _EXTRA -- Any keywords that are appropriate for the WRITE_*** routines are
; also accepted via keyword inheritance.
;
; COMMON BLOCKS:
;
; None
;
; RESTRICTIONS: Requires IDL 5.2 and higher.
;
; MODIFICATION HISTORY:
;
; Written by David W. Fanning, 9 AUG 2000.
; Added changes to make the program more device independent. 16 SEP 2000. DWF.
; Removed GIF file support for IDL 5.4 and above. 18 JAN 2001. DWF.
; Added NODIALOG keyword. 28 MAR 2001. DWF.
; Added an output CANCEL keyword. 29 AUG 2001. DWF.
; Added ERROR_MESSAGE code to file. 17 DEC 2001. DWF.
; Added ORDER keyword. 25 March 2002. DWF.
; Now create 24-bit PNG files if reading from a 24-bit display. 11 May 2002. DWF.
; Now create 24-bit BMP files if reading from a 24-bit display. 23 May 2002. DWF.
; Removed obsolete STR_SEP and replaced with STRSPLIT. 27 Oct 2004. DWF.
; Unleashed the GIF code for IDL 6.2 and above. 10 Nov 2005. DWF.
; Rolled back previous change to IDL 6.1. 24 Jan 2006. DWF.
; Fixed a problem in which 16-bit displays were treated as 24-bit displays,
; and as a result could not produce WHITE colors. Now all 16-bit displays
; are treated as 8-bit displays. It is an ugly trade-off. 24 Jan 2006. DWF.
; Added TYPE keyword 27 Sep 2006. DWF.
; Updated program to work with 24-bit Z-buffer in IDL 6.4. 11 June 2007. DWF.
; Added OVERWRITE_PROMPT keyword. 2 Oct 2008. DWF.
; Found an extra line of code that wrote PNG files twice! Removed. 10 Nov 2010. DWF.
; Replaced TVREAD_ERROR_MESSAGE with ERROR_MESSAGE. 25 Nov 2010. DWF.
;-
;
;******************************************************************************************;
; Copyright (c) 2008, by Fanning Software Consulting, Inc. ;
; All rights reserved. ;
; ;
; Redistribution and use in source and binary forms, with or without ;
; modification, are permitted provided that the following conditions are met: ;
; ;
; * Redistributions of source code must retain the above copyright ;
; notice, this list of conditions and the following disclaimer. ;
; * Redistributions in binary form must reproduce the above copyright ;
; notice, this list of conditions and the following disclaimer in the ;
; documentation and/or other materials provided with the distribution. ;
; * Neither the name of Fanning Software Consulting, Inc. nor the names of its ;
; contributors may be used to endorse or promote products derived from this ;
; software without specific prior written permission. ;
; ;
; THIS SOFTWARE IS PROVIDED BY FANNING SOFTWARE CONSULTING, INC. ''AS IS'' AND ANY ;
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES ;
; OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT ;
; SHALL FANNING SOFTWARE CONSULTING, INC. BE LIABLE FOR ANY DIRECT, INDIRECT, ;
; INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED ;
; TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; ;
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ;
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ;
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS ;
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ;
;******************************************************************************************;
FUNCTION TVREAD, xstart, ystart, ncols, nrows, $
BMP=bmp, $
Cancel=cancel, $
Colors=colors, $
Cube=cube, $
Dither=dither, $
_Extra=extra, $
Filename=filename, $
GIF=gif, $
JPEG=jpeg, $
NoDialog=nodialog, $
Order=order, $
Overwrite_Prompt=overwrite_prompt, $
PICT=pict, $
PNG=png, $
TIFF=tiff, $
True=true, $
TYPE=type, $
Quality=quality, $
WID=wid

; Error handling.

Catch, theError
IF theError NE 0 THEN BEGIN
Catch, /Cancel
;ok = Error_Message()
IF N_Elements(thisWindow) EQ 0 THEN RETURN, -1
IF thisWindow GE 0 THEN WSet, thisWindow
RETURN, -1
ENDIF

cancel = 0

; Check for availability of GIF files.

thisVersion = Float(!Version.Release)
IF (thisVersion LT 5.3) OR (thisVersion GE 6.1) THEN haveGif = 1 ELSE haveGIF = 0

; Go to correct window.

IF N_Elements(wid) EQ 0 THEN wid =!D.Window
thisWindow = !D.Window
IF (!D.Flags AND 256) NE 0 THEN WSet, wid

; Check keywords and parameters. Define values if necessary.

IF N_Elements(xstart) EQ 0 THEN xstart = 0
IF N_Elements(ystart) EQ 0 THEN ystart = 0
IF N_Elements(ncols) EQ 0 THEN ncols = !D.X_Size - xstart
IF N_Elements(nrows) EQ 0 THEN nrows = !D.Y_Size - ystart
IF N_Elements(order) EQ 0 THEN order = !Order
IF N_Elements(true) EQ 0 THEN true = 1
dialog = 1 - Keyword_Set(nodialog)

; Do you want to write an image file instead of
; capturing an image?
IF N_Elements(type) NE 0 THEN BEGIN
CASE StrUpCase(type) OF
'BMP': bmp = 1
'GIF': gif = 1
'JPEG': jpeg = 1
'JPG': jpeg = 1
'PICT': pict = 1
'PNG': png = 1
'TIFF': tiff = 1
'TIF': tif = 1
ELSE: Message, 'Cannot write a file of type: ' + StrUpCase(type) + '.'
ENDCASE
ENDIF
writeImage = 0
fileType = ""
extention = ""
IF Keyword_Set(bmp)THEN BEGIN
writeImage = 1
fileType = 'BMP'
extension = 'bmp'
ENDIF
IF Keyword_Set(gif) THEN BEGIN
IF havegif THEN BEGIN
writeImage = 1
fileType = 'GIF'
extension = 'gif'
ENDIF ELSE BEGIN
ok = Dialog_Message('GIF files not supported in this IDL version. Replacing with JPEG.')
writeImage = 1
fileType = 'JPEG'
extension = 'jpg'
ENDELSE
ENDIF
IF Keyword_Set(jpeg) THEN BEGIN
writeImage = 1
fileType = 'JPEG'
extension = 'jpg'
ENDIF
IF Keyword_Set(PICT) THEN BEGIN
writeImage = 1
fileType = 'PICT'
extension = 'pict'
ENDIF
IF Keyword_Set(png) THEN BEGIN
writeImage = 1
fileType = 'PNG'
extension = 'png'
ENDIF
IF Keyword_Set(tiff) THEN BEGIN
writeImage = 1
fileType = 'TIFF'
extension = 'tif'
ENDIF

IF N_Elements(colors) EQ 0 THEN colors = 256
IF N_Elements(quality) EQ 0 THEN quality = 75
dither = Keyword_Set(dither)

; On 24-bit displays, make sure color decomposition is ON.

IF (!D.Flags AND 256) NE 0 THEN BEGIN
Device, Get_Decomposed=theDecomposedState, Get_Visual_Depth=theDepth
IF theDepth GT 8 THEN BEGIN
Device, Decomposed=1
IF theDepth EQ 24 THEN truecolor = true ELSE truecolor = 0
ENDIF ELSE truecolor = 0
IF thisWindow LT 0 THEN $
Message, 'No currently open windows. Returning.', /NoName
ENDIF ELSE BEGIN
truecolor = 0
theDepth = 8
ENDELSE

; Fix for 24-bit Z-buffer.
IF (Float(!Version.Release) GE 6.4) AND (!D.NAME EQ 'Z') THEN BEGIN
Device, Get_Decomposed=theDecomposedState, Get_Pixel_Depth=theDepth
IF theDepth EQ 24 THEN truecolor = true ELSE truecolor = 0
ENDIF


; Get the screen dump. 2D image on 8-bit displays. 3D image on 24-bit displays.

image = TVRD(xstart, ystart, ncols, nrows, True=truecolor, Order=order)

; Need to set color decomposition back?

IF theDepth GT 8 THEN Device, Decomposed=theDecomposedState

; If we need to write an image, do it here.

IF writeImage THEN BEGIN

; Get the name of the output file.

IF N_Elements(filename) EQ 0 THEN BEGIN
filename = 'idl.' + StrLowCase(extension)
ENDIF ELSE BEGIN
filename = filename + "." + StrLowCase(extension)
ENDELSE
IF dialog THEN filename = Dialog_Pickfile(/Write, File=filename, OVERWRITE_PROMPT=Keyword_Set(overwrite_prompt))

IF filename EQ "" THEN BEGIN
cancel = 1
RETURN, image
ENDIF

; Write the file.

CASE fileType OF

'BMP': BEGIN
IF truecolor THEN BEGIN
; BMP files assume blue, green, red planes.
temp = image[0,*,*]
image[0,*,*] = image[2,*,*]
image[2,*,*] = temp
Write_BMP, filename, image, _Extra=extra
ENDIF ELSE BEGIN
TVLCT, r, g, b, /Get
Write_BMP, filename, image, r, g, b, _Extra=extra
ENDELSE
END

'GIF': BEGIN
IF truecolor THEN BEGIN
CASE Keyword_Set(cube) OF
0: image2D = Color_Quan(image, 1, r, g, b, Colors=colors, Dither=dither)
1: image2D = Color_Quan(image, 1, r, g, b, Cube=2 > cube < 6)
ENDCASE
ENDIF ELSE BEGIN
TVLCT, r, g, b, /Get
image2D = image
ENDELSE
Write_GIF, filename, image2D, r, g, b, _Extra=extra
END

'JPEG': BEGIN
IF truecolor THEN BEGIN
image3D = image
ENDIF ELSE BEGIN
s = Size(image, /Dimensions)
image3D = BytArr(3, s[0], s[1])
TVLCT, r, g, b, /Get
image3D[0,*,*] = r[image]
image3D[1,*,*] = g[image]
image3D[2,*,*] = b[image]
ENDELSE
Write_JPEG, filename, image3D, True=1, Quality=quality, _Extra=extra
END

'PICT': BEGIN
IF truecolor THEN BEGIN
CASE Keyword_Set(cube) OF
0: image2D = Color_Quan(image, 1, r, g, b, Colors=colors, Dither=dither)
1: image2D = Color_Quan(image, 1, r, g, b, Cube=2 > cube < 6)
ENDCASE
ENDIF ELSE BEGIN
TVLCT, r, g, b, /Get
image2D = image
ENDELSE
Write_PICT, filename, image2D, r, g, b
END

'PNG': BEGIN
IF truecolor THEN BEGIN
Write_PNG, filename, image, _Extra=extra
ENDIF ELSE BEGIN
TVLCT, r, g, b, /Get
image2D = image
Write_PNG, filename, image2D, r, g, b, _Extra=extra
ENDELSE
END

'TIFF': BEGIN
IF truecolor THEN BEGIN
image3D = Reverse(image,3)
ENDIF ELSE BEGIN
s = Size(image, /Dimensions)
image3D = BytArr(3, s[0], s[1])
TVLCT, r, g, b, /Get
image3D[0,*,*] = r[image]
image3D[1,*,*] = g[image]
image3D[2,*,*] = b[image]
image3D = Reverse(Temporary(image3D), 3)
ENDELSE
Write_TIFF, filename, image3D, 1, _Extra=extra
END
ENDCASE
RETURN, -1
ENDIF

; Return the screen dump image.

RETURN, image
END ;-------------------------------------------------------------------------------