How to import and cut n images in 6 parts hopefully proportional to the written and export them to a directory?

Update 2

This is a better implementation of the parts function that does not assume that the spacings are the same. It finds groups of rows in the image that are not composed of entirely white pixels and splits by those groups.

ClearAll@parts

parts[image_] := Module[{width, height, imageData},
  {width, height} = ImageDimensions@image;
  imageData = ColorConvert[image, "Grayscale"] // ImageData;

  imageData // 
  Position[#, ConstantArray[1., width]] & //       
  Flatten //
  Complement[Range[height], #] & //     
  Split[#, (#2 - #1 == 1 &)] & //
  Map[MinMax] //   
  Map[Take[imageData, #] & /* Image]]

The rest of the code in the update below is unchanged.

Update

To process a directory of images

importPath = "path to import directory";
exportPath = "path to export directory"; (* Must already exist *)

ClearAll[parts, exporter];

parts[image_] := ImagePartition[image, Scaled[{1, 1/6}]] // Flatten

exporter[baseName_, parts_] := 
 MapThread[
  Export[baseName <> "_" <> #1 <> ".png", #2] &, {{"a", "b", "c", "d", "e", "f"}, parts}]

importedImages = AssociationMap[Import, FileNames["*.png", importPath]];

importedImages // 
  KeyValueMap[exporter[FileNameJoin[{exportPath, FileBaseName@#1}], parts[#2]] &];

---

If the spacing between the text is the same then you can partition it

img = Import["~/Downloads/21ttc.png"];
parts = ImagePartition[img, Scaled[{1, 1/6}]] // Flatten

Each image in the list can be exported to a different file.

MapThread[Export["P01_" <> #1 <> ".png", #2] &, {{"a", "b", "c", "d", "e", "f"}, parts}]