Minimal images support

[webcarrot]

Minimal/primitive images support:

• images put into formImage.Pages[].Images[]
• does not analyze, verify or convert image data
• omits position, scaling etc
• skip groups, masks and inline images
• omits duplicates

Typical output:

{
  "formImage": {
    "Transcoder": "[email protected] [https://github.com/modesty/pdf2json]",
    "Agency": "",
    "Id": {
      "AgencyId": "",
      "Name": "",
      "MC": false,
      "Max": 1,
      "Parent": ""
    },
    "Pages": [
      {
        "Height": 52.625,
        "HLines": [],
        "VLines": [],
        "Fills": [
          {
            "x": 0,
            "y": 0,
            "w": 0,
            "h": 0,
            "clr": 1
          }
        ],
        "Texts": [],
        "Fields": [],
        "Boxsets": [],
        "Images": [
          {
            "src": "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQEASABIAAD//gATQ3JlYXRlZCB3aXRoIEdJTVD/2wBDAAMCAgMCAgMDAwMEAwMEBQgFBQQEBQoHBwYIDAoMDAsKCwsNDhIQDQ4RDgsLEBYQERMUFRUVDA8XGBYUGBIUFRT/wgALCAABAAEBAREA/8QAFAABAAAAAAAAAAAAAAAAAAAACP/aAAgBAQAAAAEqf//EABQQAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQEAAQUCf//EABQQAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQEABj8Cf//EABQQAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQEAAT8hf//aAAgBAQAAABD/AP/EABQQAQAAAAAAAAAAAAAAAAAAAAD/2gAIAQEAAT8Qf//Z"
          },
          {
            "width": 1,
            "height": 1,
            "data": {
              "0": 255,
              "1": 255,
              "2": 255,
              "3": 255
            }
          }
        ]
      }
    ],
    "Width": 37.188
  }
}
`

[modesty]

base64 encoded image output, nice add-on, thanks. It'd be less impact on current clients if it's optional, controlled by a new command line arg, for example.

[jonaskello]

What is the status of this PR? Seems there is still not any support for parsing information about images?

[jonaskello]

@modesty If we fix the merge conflicts of this PR would it be possible to merge it?

[fancydev18]

Please, this would be so useful! Would it be possible to merge it? @modesty

[modesty]

please, fix the conflicts first

[jonaskello]

@modesty I opened a new PR in #253 that has conflicts resolved. Could you please review it?

[webcarrot]

-> #253

[modesty]

a few notes:

1. Minimal images support (updated) #253 still has conflicts. An easier way would be to create a new branch based off master then reapply change and submit new PR
2. More importantly, JSON is data exchange text format, generally not for binary data, including images. A preferred way is to create separate image files, like how other parsed files work
3. Another reason for supporting image separately is performance, it should be an opted-in process for requested caller, needs to be off by default for common use cases to avoid unnecessary CPU cycles and memory usage. A new command line switch is recommended
4. Coding wise, lib/imagedata.js is a new file with single function exported while referencing this internally. Better to encapsulate all image related data and ops in lib/pdfimage.js file, extending it with functionality of your lib/imagedata.js and function addImage(image, images)
5. needs sample testing PDF. you can add it to test/pdf/misc and add more test script

thanks.

[jonaskello]

@modesty Thanks for the input, I'll try to find some time to go through all of your feedback :-). Just a quick note about #253, when I view the PR github says "This branch has no conflicts with the base branch". I'm not sure where to look for the conflicts you mentioned?