Hello Muhammad,

from your post I could not find out whether the characters have a fixed specific color or not. If they do have a specific color, then a solution might be (let img be your original image):

red = {.93, .1, .15};
letterImg = ImageApply[If[EuclideanDistance[#, red] < .2, 0, 1] &, img]

giving:

which can be treated with TextRecognize. If one uses the documentation the result is frustrating: It simply does not work! Only when choosing a non-documented (!) option, things appear to work a bit:

I myself learned about this valuable option (and more) from another interesting post of Marco Thiel (thanks Marco!). I do not understand why those details are undocumented. (In case it is documented meanwhile (v10.3.1), then just ignore my last remark.)

Regards -- Henrik

Hello Muhammad,

I am afraid I did not read you first post careful enough, sorry! OK, here comes another try:

Let img be your original image, then I construct and apply a sort of an "edge mask":

img1 = ColorQuantize[img, 15];
edgeMask = ColorNegate@Dilation[EdgeDetect[img1], 2];
img2 = ImageMultiply[img1, edgeMask]

which gives:

Having done this preparation we can convince ourself that MorphologicalComponents does the trick:

(mc = MorphologicalComponents[img2]) // Colorize

This results in more than 1000 components, which are represented in their own part of the image (using automated crop). Since the font size is fixed, one can have a rough idea about the expected size of those images which contain letters:

{min, max} = MinMax[mc]
(* Out:  {0, 1029} *)

levelImages = ParallelTable[{n, i = Function[{level}, ImageCrop@Image@Map[If[# == level, 0, 1] &, mc, {2}]][n], 
    ImageDimensions[i]}, {n, min, max}];

letterCandidats = Select[levelImages, With[{xdim = #[[3, 1]], ydim = #[[3, 2]]}, (40 < xdim < 70) && (40 < ydim < 70)] &];

{#1, #2, TextRecognize[#2, "SegmentationMode" -> 6]} & @@@ letterCandidats

The result then looks like:

Maybe this might be a way for an approach . Regards -- Henrik

You should post sample images and some initial CODE that you wrote.