13 Replies Latest reply on Mar 6, 2008 3:37 AM by Pete Lees

    Low color depth conversions

    nike37773
      Folks, I am using RoboHelp 6 and am importing a 260 page Word doc and converting it to CHM. I am somewhat bummed about the quality of the images in the final file as we've put some considerable time into getting quality images. Most of the the images in the Word doc are jpegs. The resulting images in the CHM file are really pixelated.

      Is there anything I can do while uploading the doc to force RoboHelp to upload the original images and not compress and "mess" up the images?
        • 1. Re: Low color depth conversions
          ElisaFnord Level 2
          Hi, nike37773, and welcome to the forums.

          I don't think RoboHelp is compressing your jpegs - I think Word already has. Word has a really cool compression algorithm for insert>picture that keeps the documents smaller but gives beautiful display and print results. However, it's lossy, and when the picture comes back out of Word, it gets pretty grainy.

          I haven't experimented with importing a Word document with pictures included by reference, but I have overwritten RoboHelp's image files with the originals and gotten good results.

          HTH,
          Elisa
          • 2. Re: Low color depth conversions
            nike37773 Level 1
            Thank you for that pointer Elisa! Any ideas if it's possible to circumnavigate this algorithm? Is it possible to somehow dissect the CHM and put high quality images in there?

            I take it you were working on a WebHelp project as opposed to an HTML Help project which makes CHM when you were overwriting the images?
            • 3. Re: Low color depth conversions
              Peter Grainge Adobe Community Professional
              When you generate the help, one of the options in the dialog is the format of the images. Have you checked they are not being converted to GIFS as that would reduce the quality.

              • 4. Low color depth conversions
                nike37773 Level 1
                Peter, my output format is Microsoft HTML Help and as I am about to generate the final output - the only things i see on the dialog are fields where i can change the output folder and file name, set the conditional build expression and two fields where i can define the default Topic and the default Window.

                The only thing I see on the dialog that might be closely related to compression is a checkbox that says "Optimize CHM File Size". I have unchecked it and have generated several projects and have not seen any difference in file size. Whether I check it or not, I still get the following message at the conclusion of the compilation process:

                ".....Compression decreased file by 3,357,974 bytes.
                Finished compiling HTMLHELP in 46 sec(s)
                Compilation complete."


                Is there any way to turn this compression off? My original Word file is 13mb and the generated CHM file is 10mb - i figure the 3mb that I'm loosing are directly related to image quality....?
                • 5. Re: Low color depth conversions
                  Pete Lees Level 2
                  Hi, nike37773,

                  There's no option to turn off the compression process, as Microsoft didn't take this requirement into account when building the HTML Help compiler. Or more likely this was by design; HTML Help files have quite a lot in common with other compressed formats, such as cabinet (.cab) files. In any case, the compression is never achieved at the expense of reduced image quality, in the same way that adding images to a Zip file has no effect on their quality.

                  I may be mistaken about this, but I had a feeling that RoboHelp's "Optimize CHM file size" feature works by stripping unnecessary markup from the HTML source prior to compilation — kadov tags and the like. Some other tools can improve on the compression rate that the HTML Help compiler achieves and squeeze further dead space from the help file.

                  If you no longer have access to the original source images that you added to the Word document, you could try saving the document as a Web page. This sometimes allows you to recover high-quality versions of the images.

                  Pete
                  • 6. Re: Low color depth conversions
                    Peter Grainge Adobe Community Professional
                    Are you using RH HTML or RH for Word and which version?

                    • 7. Re: Low color depth conversions
                      nike37773 Level 1
                      I've been using RH HTML... are you saying I should probably use RH Word?!
                      • 8. Re: Low color depth conversions
                        Peter Grainge Adobe Community Professional
                        NO! I want to see what options you are being given. You haven't said which version, 5,6 or 7?

                        • 9. Re: Low color depth conversions
                          nike37773 Level 1
                          oh! my fault, I have version 6.
                          • 10. Re: Low color depth conversions
                            Peter Grainge Adobe Community Professional
                            Checking again it is in fact RH for Word that gives you an option to select JPG or GIF when creating the CHM. However, I don't think that is the solution. Otherwise we would all be having problems.

                            Take a look at my site. There's a topic on importing and a topic on images. Maybe something there will help.

                            • 11. Low color depth conversions
                              nike37773 Level 1
                              quote:

                              Originally posted by: Peter Grainge
                              Take a look at my site. There's a topic on importing and a topic on images. Maybe something there will help.


                              Yep, checked that, but didn't exactly find what I was looking for... My main issue being that I've created about 600 images for this manual already, took screenshots with RH ScreenCapture, copied and pasted into Word, where I resized them as necessary. To retake all of the screenshots and then resize them with the ReSize tool isn't really much of a solution, not only because it means redoing the whole manual, but because the images in the manual are constantly being resized when content is added in an effort to keep the page breaks neat. All of which leads me to think Elisa is on to something when she said:
                              quote:

                              Originally posted by: Elisa Firth
                              Word has a really cool compression algorithm for insert>picture that keeps the documents smaller but gives beautiful display and print results. However, it's lossy, and when the picture comes back out of Word, it gets pretty grainy.



                              Regarding the other recommendation I've received - I am having a problem understanding what you folks mean when you say "switch the high res images for the low res images"
                              quote:

                              Originally posted by: Elisa Firth
                              ...I have overwritten RoboHelp's image files with the originals and gotten good results.

                              quote:

                              Originally posted by: Pete Lees
                              If you no longer have access to the original source images that you added to the Word document, you could try saving the document as a Web page. This sometimes allows you to recover high-quality versions of the images.

                              I have saved the Word doc as a web page and do see the higher resolution images along with the lower resolution images. It seems to me that RH is taking the lower resolution images...

                              The thing is, once the project is compiled, the only thing we use out of all of the generated files is the CHM that is located in the .."!SSL!\Microsoft_HTML_Help\" folder. Where should the actual switching of the images happen? I really do not want this to be an manually intensive process as I see us building and rebuilding this project many times over!
                              • 12. Re: Low color depth conversions
                                ElisaFnord Level 2
                                Oh, dear.

                                When RoboHelp imports a Word file, it saves each embedded image as a .gif in the source files. You can see these images in the Project pane - open up the Images fake folder instead of the HTML Topics fake folder. The image files may be directly under Images or they may be in a sub-folder.

                                When Peter and I said "replace the images," we had in mind that you could re-save each original .gif or jpg file over the image file that RoboHelp saved during import. Lots of Save As work, but faster than recapturing. Once the images are in the source, they are included when you generate your .chm file. And if you change an image, you have to change the .gif in the RH source file.

                                But you don't have the original .jpgs, and because the images have already been compressed in Word, they are grainy .gifs. Which means a) redoing the captures or b) finding a setting you can use. And then there's Peter's idea of saving the Word manual as HTML, then importing the HTML files instead of Word. That might work.

                                Tell me, are you doing the original development in Word and just running each release of the manual through RoboHelp to get the online help version? Because if you're going to be revising this online help periodically, it might make more sense to make the RoboHelp source files your primary source and generate Word from RH. There are some formatting issues (Word and HTML are fundamentally incompatible about issues like bullet lists), but I've managed to make it work pretty smoothly.

                                HTH,
                                Elisa
                                • 13. Re: Low color depth conversions
                                  Pete Lees Level 2
                                  The PNG files that you recover when you save a Word document as a Web page have the same file names as the GIF equivalents, other than the file extension obviously. Is there any scope for searching the RoboHelp source for the GIF file names and replacing them with the PNG names?

                                  Pete