[build 396] Colorize Document feature can't convert images with BPC of 1 and ColorSpace of DeviceGray to specified color

[rakunavi]

Hello all,

I noticed that the "Colorize Document" feature added in build 396 cannot convert images with BPC of 1 and ColorSpace of DeviceGray to the specified color.

The sample file consists of three pages, each converted using the "Rasterize Pages" function of the PDF-XChange Editor with the following settings.

• (Page 1) Type: Color, Compression: ZIP
• (Page 2) Type: Grayscale, Compression: ZIP
• (Page 3) Type: Black & White, Compression: ZIP

With Edit Objects mode enabled, the image properties for each page are as follows.

• (Page 1) BPC: 8, Compression: ZIP, Color Space: DeviceRGB
• (Page 2) BPC: 8, Compression: ZIP, Color Space: DeviceGray
• (Page 3) BPC: 1, Compression: ZIP, Color Space: DeviceGray

• sample.pdf

For this sample file, if you specify "Colorize Document" as Type in the "Colorize Document" dialog and convert the colors, only page 3 will not be converted to the specified color. Some colors are converted, but there is a regularity in the colors that can and cannot be converted. The explanation of the regularity is off topic, so it is omitted here.

• Animation1.gif

A workaround does exist. As shown in the figure below, select the image in Edit Objects mode and run the "Recompress Image" command to convert it to RGB (Step 1), then run the "Recompress Image" command again to convert it to Monochrome or Indexed (Step 2). After this, the colors are converted in the "Colorize Document" dialog (Step 3).

• figure.png
  
  
  Animation2.gif

I posted this message in this subforum because I am not sure if this is an issue report or a feature request, but I think it would be ideal if users could just use the "Colorize Document" dialog to complete the process without having to take such workarounds.

Also, as already explained, the "Recompress Image" command is executed with RGB specified in Step 1 and Monochrome or Indexed in Step 2. Running the command twice is redundant, so it would be appreciated if Monochrome or Indexed could be selected from a drop-down list at Step 1.

• dialog.png

Hoping that the above information will be of some help to you.
Thank you so much for your continued support.

Best regards,
rakunavi

- PDF-XChange Editor PRO Version: 10.6.0 build 396
- OS Version: Windows 11 Pro / Home 24H2 Build 26100.3775
- PC Model: GMKtec Nucbox M7 Pro with HUION Kamvas Pro 19 / Lenovo IdeaPad C340-15IWL

[Daniel - PDF-XChange]

Hello, rakunavi

Thank you for the report, after reproducing it, I have passed along the initial issue to our bug team, while the secondary item is now with the Devs for evaluation as a feature request.

[Primary bug report, in progress with Dev team, no ticket made]

[secondary request in review, ticket made]:
RT#7477: FR: one step recompress devicegray > indexed

Kind regards,

[rakunavi]

Hello Daniel, thank you for contacting developers.

Currently, the Colorize Document feature works at the page level, but it would be greatly appreciated if it could be done from the context menu of the base content, similar to the Recompress Images feature. There would be as much demand for colorization at the object level as at the page level.

I am sure the developer is already planning this, but let me make the request just in case.

Best regards,
rakunavi

[Stefan - PDF-XChange]