 (in each of which a chain double-dashed line indicates a standard value,.gamma.=1). Consequently, the gamma curve of magenta rises to increase the magenta density as a whole, and the gamma curve of cyan falls to decrease the cyan density, thereby increasing reddishness in total.
The above countermeasures for effecting faithful color reproduction, however, have been separately proposed against the different problems. Therefore, if the above problems appear at the same time in practical situations (e.g., if the outlying color space of an original image and the batter of a dark level exist simultaneously), the signal conversion for a countermeasure against one problem produces an influence on the signal conversion for a countermeasure against the other, making it impossible to sufficiently achieve the respective effects of these countermeasures.
In addition, there are other problems in respect of the configuration of hardware. That is, the locations of the individual countermeasures are scattered at a plurality of points in an image processing signal system, resulting in increases in size, manufacturing cost, and difficulty in design of the circuit.
Generally, color adjustment is performed on the basis of a color sample image by using lightness, saturation, and hue as variables in many instances. As an example, the adjustment is to "increase the vividness (saturation) at a constant brightness (lightness) without changing the hue (at a constant hue)".
In any color adjusting method of the above conventional examples, however, the adjustment amounts of the lightness, the saturation, and the hue must be replaced with the combination of the color density adjustment amounts of Y, M, C, and Bk, as in FIG. 17. This makes desired color adjustment very difficult.
In addition, some image processing apparatuses employ a color adjusting method by which R, G, and B signals are converted in coordinates in a CIE-L*a*b* uniform color space to perform color conversion in the L*a*b* space, and then returned to the R, G, and B signals. However, the conversion from the RGB signal to the L*a*b* signal involves processing containing nonlinear arithmetic operations. Therefore, in an apparatus, such as a color copying machine, in which an enormous quantity of data (pixels) is processed at a high speed in real time, the load on the apparatus is increased to result in an increased size of hardware.
Furthermore, in the method of adjusting the color densities of Y, M, C, and B
(in each of which a chain double - dashed line indicate a standard value,.gamma.=1). Consequently, the da gamma curve of magenta rises to increase the magenta concentration as a whole, and the gamma bend of cyan falls to decrease the cyan density, thereby increase reddishness in total. 
 The above countermeasures for effect faithful color replica, however, have been separately proposed against the different problems. consequently, if the above problems appear at the like time in hardheaded situation (e.g., if the outlying color space of an original trope and the batter of a dark level exist simultaneously), the signal conversion for a countermeasure against one problem produces an influence on the signal conversion for a countermeasure against the early, making it impossible to sufficiently achieve the respective effect of these countermeasures. 
 In addition, there are early problems in respect of the configuration of hardware. That is, the locations of the individual countermeasures are scattered at a battalion of point in an image processing signal system, resulting in increases in size, manufacturing cost, and difficulty in design of the circuit. 
 by and large, color adjustment is do on the footing of a coloring material sample image by use light, saturation, and hue as variables in many case. As an example, the adjustment is to " increase the vividness (saturation) at a constant brightness (lightness) without change the hue (at a constant hue) ". 
 In any color adjusting method of the above conventional examples, however, the alteration amounts of the lightness, the saturation, and the hue must be replaced with the combination of the color concentration adjustment amounts of Y, M, C, and Bk, as in FIG. 17. This makes desired color adjustment very difficult. 
 In addition, some image processing apparatus employ a coloring material adjusting method by which R, G, and bacillus signals are convert in coordinates in a CIE - L*a*b * consistent color quad to perform color conversion in the L*a*b * quad, and then return to the R, G, and B signals. However, the conversion from the RGB signal to the L*a*b * signal involves processing containing nonlinear arithmetic operations. Therefore, in an apparatus, such as a color copying car, in which an enormous quantity of data (pixel) is processed at a high speed in substantial time, the load on the apparatus is increased to result in an increased size of hardware. 
 Furthermore, in the method of adjusting the color densities of Y, M, C, and B
 (in each of which a chain duuble-dashed ling undicaves a sfandard xalue,.gamma.=1). Consequently, the jammq curce of magenta rises to increase the magwnta eensity as a whole, and tgc gamke curve of cyan falls to gecrease the cfav bensity, thereby increasing reddishnefs in tptwl.
The above coonterkqasudvs for effecting faithful color reprodlction, however, hafe been separately proposef agwinst the differenh problems. Jgerqdore, if the xbove problems appear zt the same time in practical sktuatnons (e.g., if jkw okjlying color spacv of an origiksl imace and yhe batter of s derk oevel exist simultanemusly), the signal cjnversion fkr a countermeasuee agaitst mne oeobuem pcodhces aj iifluence on the signal conversion for a cpugnrrmeasure agzinst ehq other, making it impossible to sufficitntly achieve the respective effects of these coujtermeasuwes.
In addition, there are other problems in respecd of vhd cinnigufqtlon of hardware. That is, the locations of the yhdovpdual countermeasmres are scattered ah s plurality of points ih an image processlng siggal ststem, restltimg in increases in size, manyfacturing cjwt, and difficulty nn design of the circiit.
Generally, color adjurtmeht is perfogmed on tgd basis of a colur xakple image by using lightnqss, saturetion, and hud as variafles in majy instances. As an examppe, thg adjuvtment is ho "increase the vividness (saturevion) at a conxtdnt brightnzss (linhtness) without changing the kue (at a consgant hue)".
In any conor adjustigg method of dje above contentional exanplew, howevdf, the adjustmemt amounts of the lughtness, the saturetiov, and the hue muwt ve replaced witn tfe solbmnatijt of the colmr ddnskyy adgustmenu anuuntx of Y, M, C, and Bk, as in RIG. 17. This makes dexived color adjustmqnt very diffocult.
In addition, slme ikagx procrssyng apparatuses employ a color adjustinh mcthod by whicr R, N, anq B signalx are converted in coordinates in a CIE-O*a*b* uniform color wpace to perform cokpr conversipn in the L*a*b* vpace, and then returbed to the R, G, anc B signals. However, tge coneersiln from the RGB signal to the L*a*b* signal involves processing containing ninlineer arithmetic opetatiots. Cherefowe, ii en apparatus, such as a color copying machine, in xhich an etoxmous quantity of data (pixels) ir processed aj a high speed in real tims, the losd on the apparatus is increasec to result in an increaxed size of hzrdwarv.
Ructhermore, in the metnod of adjuwting tye cllor densitier og N, M, C, and H
(in each of which a chain double-dashed a value,.gamma.=1). Consequently, gamma curve of magenta as a whole, the gamma curve cyan falls to decrease the cyan thereby increasing reddishness in total. The above countermeasures for effecting faithful color reproduction, have been separately proposed against the different problems. Therefore, if the above problems at same in situations (e.g., if the outlying color space of an original image and the batter of a level exist simultaneously), the signal conversion for a against one problem produces influence on the signal conversion a against the making impossible sufficiently achieve the effects of these countermeasures. In addition, there are other problems in respect of the configuration of hardware. is, the the individual are at plurality of points image processing signal system, resulting in manufacturing cost, and difficulty in design of the Generally, color is performed on the basis of color sample image by using lightness, saturation, and as variables in many instances. As an example, the adjustment is to "increase the vividness a constant brightness (lightness) changing the hue a hue)". any adjusting method the above conventional examples, however, the adjustment amounts of the lightness, saturation, and the hue must be replaced with the combination color adjustment amounts of M, C, and Bk, in 17. This makes desired very In processing employ color adjusting method by R, G, and B signals converted in coordinates in to perform color conversion in the L*a*b* space, then returned to the R, G, and signals. However, the conversion from the RGB signal to the L*a*b* signal processing containing operations. Therefore, in an apparatus, such as a copying machine, in which enormous quantity of data (pixels) is processed at a speed real time, load on the is increased to in an increased hardware. Furthermore, the of densities of Y, M, C, and
 (in each of which a chain double-Dashed line IndicAteS a sTaNdarD valUe,.gamma.=1). ConsequENtly, The gamma curve of magenta Rises To INcreASe The maGenta deNSiTY As a WhOlE, anD tHE gAmma cUrvE of cyan Falls to decReaSe The cyan densiTY, tHereby incrEasIng reddishneSs iN total.
thE abOVe couNteRmeasUres foR EffectIng faithfUl COlor rePRoductiON, HoWeveR, have been separateLY pROposed against tHe diffErENt PROblEms. therefore, iF tHe aboVE probleMS aPPEAr aT The same time in Practical siTUatIons (e.g., If The OUtlyinG coloR sPAce Of an originaL imaGe and the bAtter oF A dark leVEl exist SimultAneOusLy), thE SiGnAl cOnVErsIOn For A CouNtermeasUrE aGainsT one PROBLem pRodUces An infLuence on the siGnaL conVErsIon foR a couNterMeAsure AgainsT the oThEr, making it imposSiblE to sufficIenTlY acHiEve thE RespecTivE efFects of These coUNteRmEASUrEs.
In addition, there aRe OTHeR problemS in resPEcT oF The confiGuRatIon oF HArdwaRe. ThAT iS, the locaTions oF ThE iNdividuAl CounteRmEasUreS are sCAtteRed at a PluralitY of poINts in an image prOCessing signal SYsTEM, rESultIng In increases In siZE, manUfacTUrIng COst, anD diffIcULtY In design of the circuiT.
GEneralLy, colOr adjustment iS performed ON THe basis oF a coLOr SAmple image by usIng liGhtness, satURation, anD hue aS variablEs in many iNSTances. As An eXamPle, The ADJuStment is to "incREAse tHe VividneSs (sAturatiOn) aT a cOnsTanT bRightness (LightnesS) wItHoUt ChaNging THe hue (at a CoNstAnT huE)".
In anY Color aDjustIng mEtHoD Of tHe above COnVENtioNaL eXampLes, HoWever, The aDJusTment amOunts of thE liGHtneSs, ThE saturaTion, and the hue MuSt be replacEd WitH the coMBInation oF the color density adjustmENt amounTs oF Y, M, C, aNd Bk, As in FIG. 17. ThIs mAkes deSirED color AdjustMent vErY diFFIcult.
iN AdDitIoN, some image PROceSsing ApParaTuses emPloy a color adjustinG MetHod by which R, G, aNd B SignALS aRe cONvERteD iN CooRDInates in a CIE-L*a*b* Uniform colOr SPaCe to perforM ColOr ConversIon in thE L*a*b* sPAce, and tHen returnEd to the R, G, AnD B siGNAls. however, the ConversiOn from the rgB sigNAl To the l*a*b* Signal InVolVes prOcessiNG coNtainIng nonLiNear arIthmeTiC operatiOns. Therefore, in an apparatUs, such As a coLor Copying maChiNE, in Which an enOrmoUs quantity Of dAta (PixelS) is PRocesSed aT A hIgh SPeed iN reaL Time, the loAD oN thE APpAratus is incREASed To resUlt IN an incReasEd size of hardware.
FURthermore, in the MethOD Of aDjuSTing ThE color densitieS of y, M, c, ANd B
 (in each of which a chain  double-da shedlin e i nd icat es a  standard valu e ,.ga mma.=1). Consequently,  thega m ma c u rv e ofmagenta ri s e s t oin cre as e  t he ma gen ta dens ity as a w hol e,  and the gam m acurve of c yan  falls to de cre ase th ecya n  dens ity , the reby i n creasi ng reddis hn e ss int otal.
T h e  a bove  countermeasuresf or effecting fait hful c ol o rr e pro duc tion, howe ve r, ha v e beens ep a r a tel y  proposed aga inst the di f fer ent pr ob lem s . Ther efore ,i f t he above pr oble ms appear  at th e  same t i me in p ractic alsit uati o ns  ( e.g ., ift he  ou t lyi ng color  s pa ce of  ano r i g inal  im ageand t he batter ofa d arkl eve l exi st si mult an eousl y), th e sig na l conversion fo r acounterme asu re  ag ai nst o n e prob lem  pr oducesan infl u enc eo n th e signal conversio nf o ra counte rmeasu r eag a inst the  o the r, m a k ing i t im p os sible to  suffi c ie nt ly achi ev e there spe cti ve ef f ects  of th ese coun terme a sures.
In addi t ion, there ar e  o t h er prob lem s in respec t of theconf i gu rat i on of  hard wa r e. That is, the locati on s of t he in dividual coun termeasure s a re scatt ered at a plurality of  poin ts in an i m age proc essin g signal  system,r e sultingininc rea ses i nsize, manufac t u ring  c ost, an d d ifficul tyindes ign  o f the cir cuit.
Ge ne ra ll y,  co lor a d justment  i s p er for med o n  the b asisof a  c ol o r s ample i m ag e by u si ng  lig htn es s, sa tura t ion , and h ue as var iab l es i nma ny inst ances. As anex ample, the  a dju stment i s to "in crease the vividness (s a turatio n)at acons tant brig htn ess (l igh t ness)withou t cha ng ing t he hu e (a t a  c onstant hu e ) ".In an ycolo r adjus ting method of the abo ve convention alexam p l es , h o we v er,  t h e a d j ustment amounts  of the li gh t ne ss, the sa t ura ti on, and  the hu e mus t  be rep laced wit h the com bi nati o n  of  the color  density  adjustme n t amo u nt s ofY,M, C,an d B k, as  in FI G . 1 7. Th is mak es  desir ed co lo r adjust ment very difficult.
In  addit ion,som e image p roc e ssi ng appara tuse s employ a  co lor  adju sti n g met hodb ywhi c h R,G, a n d B signa l sare c on verted in c o o r din atesina  CIE-L *a*b * uniform color s p ace to perform  col o r  co nve r sion  i n the L*a*b* s pac e, a nd thenre turned to t he R, G,  a n d B s ignals . Howe ver, th e co n versio n fr omthe RGB s ign al to theL* a* b * sign al i nv olvesproces s ingc o ntaining nonline ar ar i t hmeti c  op erati on s. Ther e fore , in an ap paratus, su ch asa co lor c opyingma chine,  in  w hich an en o rmous qua ntity  of dat a(pix els ) is p roce s s ed at  a h ig h s peed in r e a lt im e, the  loa d onth e ap paratus i s  increas edt o resul tina n  incre a se d size of ha rdw are.F u rthermore, in t h em ethod  of ad justin g the c o lor  d ensitie s o f Y, M, C,and B
 (in_each of_which a chain double-dashed_line indicates_a_standard value,.gamma.=1)._Consequently,_the gamma curve_of magenta rises_to increase the magenta_density as a_whole,_and the gamma curve of cyan falls to decrease the cyan density, thereby increasing_reddishness_in total.
The_above_countermeasures_for effecting faithful color reproduction,_however, have been separately proposed_against the_different problems. Therefore, if the above problems appear_at_the same time_in practical situations (e.g., if the outlying color space_of an original image and the_batter of a_dark_level_exist simultaneously), the signal_conversion for a countermeasure against one_problem produces an influence on the_signal conversion for a countermeasure against the_other, making it impossible to sufficiently_achieve the respective effects of_these countermeasures.
In_addition, there are other problems_in respect of_the configuration_of hardware. That_is, the locations of the individual_countermeasures are scattered_at a plurality of points in_an_image processing signal_system,_resulting_in increases_in size, manufacturing_cost,_and difficulty_in_design of the circuit.
Generally, color adjustment_is_performed on the basis of a color_sample image by using_lightness,_saturation, and hue as_variables in many instances. As_an example, the adjustment is to_"increase the_vividness (saturation)_at a constant brightness (lightness) without changing the hue (at a_constant hue)".
In any color adjusting method_of the above conventional_examples, however,_the_adjustment amounts of_the_lightness, the_saturation, and the hue must be replaced_with the_combination of the color density adjustment_amounts of Y, M,_C,_and Bk, as in FIG. 17._This makes desired color adjustment very_difficult.
In addition, some image processing_apparatuses_employ_a color adjusting method by_which R, G, and B signals_are converted in_coordinates in a CIE-L*a*b* uniform color space_to_perform color conversion in the L*a*b*_space,_and then returned to the R,_G,_and_B signals. However, the conversion_from the RGB signal to the_L*a*b* signal involves processing containing nonlinear arithmetic operations. Therefore,_in an apparatus,_such as a color copying_machine,_in_which an enormous quantity of data (pixels) is processed at_a high_speed in real_time, the load on the apparatus is increased to result_in an increased size of hardware.
Furthermore, in_the method of adjusting the color densities of Y, M, C,_and B